Category Archives: Uncategorized

Will ChatGPT / AI replace experts?

My interest in this question derives from many years working with large organisations internationally in both the public and private sector, who strive to improve their curation and uptake of institutional knowledge by the experts within the organisation. So, I am not thinking in terms of the general use of tools such as ChatGPT as simply a better Google, for use on the internet.

AI and Jobs

Will Artificial Intelligence (AI) tools make people redundant? 

Some people, undoubtedly, particularly if they are doing mundane desk-based jobs collating information or giving advice that is based on a body of accepted information. In some cases, the jobs may not be regarded as mundane, but may be be subject to procedures that are relatively easy to emulate.

But will ChatGPT or subsequent AI tools replace experts? It depends a little on what we mean by an expert.

Imagine a community centre where experts are paid to offer advice to people on their entitlement to benefits. One can well imagine an AI tool very quickly replacing the basic role of synthesising the information needed to help someone know their rights.

Is this enough? I don’t think so. Context is crucial.

The person’s situation may be complicated by multiple factors including complex domestic relationships, mental health problems, access to transport, and many others. The adviser will need to display emotional intelligence not only knowledge of the current state of legislation. It may be that in being able to get support in checking knowledge of the latest legislation on benefits, the adviser can spend more quality time with someone who is in desperate need of support.

In this example AI would not be replacing a human, but would be helping redefine the role of the human, to increase their true value to society.

AI as an on-demand wikipedia without editors

In the context of knowledge in general, the AI models that are emerging today, are being seen as ‘oracles’, able to dispense accurate and well sourced summary answers to complex questions.

However, it is worth noting that AI models such as ChatGPT have to feed off source material.  Who chooses the scope of this source material? If the material is of varying quality and provenance, what rules are embedded in the AI to help it decide on the level of trust it gives to different sources?

When such tools try to synthesise knowledge from public resources on the internet they confront the very real issue that much of what is written on a subject is copied; and often without being checked first. Even trusted actors can fall foul of using poorly researched information and unwittingly give it credibility by propagating it.

If you ask Google ‘when did the Titanic sink?’ you’ll get the basic answer pretty quick. An AI tool does not do much more. They will refer to the collision with an iceberg and broken compartments taking on water.

If I ask the question ‘why did the Titanic sink?’, things get more interesting, and the AI tool can do better than Google. However, it may not anticipate the 5 whys that inevitably result. Why was it going too fast, and so on.

I had to experiment with one AI tool to get the right question in order to get to the primary cause I was interested in:

What were the company pressures that influenced the captain of the Titanic to maintain high speed despite the risk of iceberg collisions?

The answer I received was:

There were allegations that Captain Edward J Smith was under pressure to maintain high speed despite the risk of iceberg collisions. It was claimed that he ordered to ‘make a record crossing’ thus indirectly causing the collision with the iceberg. However, it is also suggested that the Titanic hit an iceberg in 1912 because of a basic steering error, and only sank as fast as it did because an official persuaded the captain to continue sailing.

I still feel I would need a historian with expertise in this area to really delve into the history. Having a very smart on-demand dictionary is great, but is Wikipedia-without-editors (as some may see it) really enough? What about the intentions that lie behind a question or the specific context that it is being raised in? 

A historian might conceivably point me to diaries written by the captain long before the ship sailed, and only recently discovered – and are not fully digitised – that reveal the pressures he felt under to go as fast as possible.

AI and complex questions of science and history

Let’s try a much more difficult question. 

When was the science settled that the world is warming as a result of man-made emissions of greenhouse gases?

I got the following answer from an AI tool (a ChatGPT derivative):

The science of climate change has been studied for over a century. In the late 19th century, scientists first argued that human emissions of greenhouse gases could change Earth’s energy balance and climate1. The United Nations Environment Programme (UNEP) was formed in 1972 as a result of growing concern about the impact of human activities on the environment. The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by the World Meteorological Organization and the United Nations Environment Programme to provide scientific information on climate change. The IPCC Third Assessment Report in 2001 found “new and stronger evidence” that humanity’s emissions of greenhouse gases are the main cause of the warming seen in the second half of the 20th Century.

Not a bad answer, but not one I feel would satisfy an expert climate scientist. 

This is what Spencer Weart writes in The Discovery of Global Warming, referring to the seminal 1967 paper by Manabe and Wetherald:

This was the first time a greenhouse warming computation included enough of the essential factors, in particular the effects of water vapour, to seem plausible to experts. Wallace Broecker, who would later play a major role in climate change studies, recalled that it was the 1967 paper “that convinced me that this was a thing to worry about.” Another scientist called it “arguably the greatest climate-science paper of all time,” for it “essentially settled the debate on whether carbon dioxide causes global warming.” Experts in a 2015 poll agreed, naming it as the “most influential” of all climate change papers.

So I went back to the AI tool, to ask the question more precisely, and anticipating something closer to what I expected:

When were climate scientists finally convinced of the greenhouse gas theory for global warming on Earth.

I got the following answer:

The greenhouse gas theory for global warming on Earth was first proposed by Swedish scientist Svante Arrhenius in 1896. In his 1938 study, he showed that humans had already emitted enough CO2 into the atmosphere to increase the average temperature on Earth and that the Earth was responding: Over the previous 50 years, the average temperature had indeed increased as per Arrhenius’s proposed greenhouse effect. Many other theories of climate change were advanced, involving forces from volcanism to solar variation. In the 1960s, the evidence for the warming effect of carbon dioxide gas became increasingly convincing.

By around 2000, many climate scientists were convinced that the rise in temperature was likely to continue as greenhouse gases accumulated. Some predicted that an unprecedented global warming would become apparent.

Let’s forgive the fact that the tool confused Callendar with Arrhenius when  referring to the seminal 1938 paper (it was Callendar who first showed empirical evidence of man-made emissions causing global warming), or the suggestion that Arrhenius was the first to understand the carbon dioxide driven greenhouse effect (Tyndall certainly did, much earlier, but Arrhenius was the first to calculate its magnitude). 

The bigger surprise was that the AI tool did not cite or allude to the 1967 Manabe and Wetherald paper.

I am sure that new versions of ChatGPT and other tools will fix such problems when answering complex and nuanced questions.

AI in an organisational knowledge context

There is however a more fundamental issue with the use of such tools within organisations – whether public or private – that are aiming to become learning organisations and develop  a body of trusted knowledge.

Chinese walls, confidentiality and other factors mean we cannot simply let rip with open access to the information held in organisations.  And while quantity is useful to AI it is much  less important to an expert than the quality of the information and insight being parsed.

Let’s consider a scenario.

A multi-national consulting engineering company has done thousands of projects around the world. It partners with diverse international and local companies – experts in specific disciplines such as new materials, acoustics, carbon accounting, and much more – in design, project management and construction 

On the one hand, the consulting company wants its intellectual property respected, and in many cases, kept confidential. Clients and partners want the same for their contributions to projects. A complex Venn diagram emerges of private and shared information, and the insights (knowledge) that emerges from these experiences. Document management systems are used to apply both open access but also need-to-know policies, and often at quite a granular level.

Documents never get printed and left on trains because people who by virtue of their role need access to certain collections of information, get it – by design. Documents that are needed to be retained and never unintentionally lost, never are – by design. This is just basic content management good practice – notwithstanding the inability of Governments and many companies to apply these 20th Century capabilities effectively.

The issue for AI is that it would need to be able to navigate these complex access rights when providing answers to questions. The same question would have to give different answers to different people; even within the same organisation if chinese walls are not to be breached. This is the Achille’s heal of AI if it is to be commercialised in an institutional setting.

I am grateful to a relative (Jon Hayter) for making the following observation:

 Isaac Asimov clearly gave some serious thought to this when he wrote “I,Robot” 

At one point when the hero is speaking to a holographic version of his deceased mentor the programme gives him information but can only answer specific questions. At one point when he has made a statement based on his own thought processing the hologram says “That, is the right question”

On the other hand, the consulting organisation also wants to parade their experience and say that it uses its unique collective know-how on past projects in the conduct of new ones. This is in part through the tacit knowledge of their expert employees, as well as the codified experience within the organisation (guidelines, technique papers, anonymised project summaries, etc.) embodied in the lingua franca of knowledge: documents.

Resolving this tension between confidentiality and reuse is part of the art of working in complex organisations, and especially in consulting.

It begs a question as to the source set of information that an AI tool can or should use to answer a queries like:

We’ve been asked to design and manage the construction of a new theatre in north east China that will be a  showcase for regional Chinese culture, and an exemplar of sustainable construction and operation. What projects should we learn from and who would we ideally partner with?

Financial constraints, unrealistic expectations, political interference and resulting scope creep will be at least as important as innovative design and engineering, and all have to be factored into the answer.

Much of what is most useful as source material will be the tacit knowledge that is often not written down, and by definition, unparseable.  This is gold dust.

To counter the ‘not written down’ issue, some organisations conduct informal review interviews and workshops at the end of each project to tease out insights. For those enlightened consultancies that actually make time to do this, these reviews would aim to provide not only an overview of what was done (the what), but also why it was done that way.

Those candid reflections; those serendipitous encounters; those lightbulb moments – none of which appeared in the project file – might be scribbled in notebooks or might surface in those informal post-project reviews. Sometimes it has to wait till the exit interview or even retirement (to save the blushes)!

As things stand, only true experts can navigate the intersection between technical know-how, personal testimony, historical and current context, emotional factors, politics, deep insights, and much more, that explain the why’s and wherefore’s of key decisions on complex endeavours. 

Would ChatGPT conjure up a Sidney Opera House design out of the blue if nothing remotely similar existed beforehand?

You know the answer.

That does not mean that the AI of the future cannot play a role as an assistant in these endeavours – taking on some of the mundane tasks that exist in the curation of information and even knowledge.

For example, in the business of applying subject-specific metadata based on controlled vocabularies, AI could certainly prove a powerful assistant by making time-consuming tasks more efficient, if not quite a complete replacement for the expert knowledge curator.

However, I am confident that for the foreseeable future, it will not replace the true expert within an organisation.

Your job is safe.

(c) Richard W. Erskine, May 2023


Filed under Uncategorized

Heating a listed Cotswold stone building with an air-source heat pump: our journey

Here is a plot spoiler: my wife and I are delighted with the results of living in our listed Cotswold stone home heated by an air-source heat pump since December 2021. I want to share our story as a corrective to the belief, widely expressed in the media, that it would be impossible to do what we did: self-evidently, this is untrue.

In case you want answers to the burning questions I often hear, I’ve collected a few (see Note [1]).

Here’s our story.


Twenty five years ago my wife and I bought an old Grade 2 Listed property with friends and split it in two.  It was a bargain; ignoring the subsequent years of work! Renovations of sash windows and shutters, valley gutter lead work, lime mortar of the end terrace, and so much more, followed over the years.

It turned out the party wall used to be an external wall when the property was first built in 1805, but about a decade later the mill-owner who acquired it wanted something much more substantial. He extended the small cottage outwards and upwards into what was advertised later as a “capital messuage”. Not a property I’d ever imagined owning, but somehow we found ourselves as custodians of this beautiful property.

When we arrived there was a higgledy piggledy array of partitioned rooms created for the care home it had been used for prior to its closure. We set about restoring it to its former Georgian glory. But there is always something to do on an old house, and the journey continues. That’s why it always amuses me when people talk about ‘retrofit’ as if it is some fast and easy project, because from my point of view, maintaining the fabric of a property is always a process not an event; a process that never really ends.

We couldn’t find any way to split the existing water, gas and electricity utilities in two, externally or internally. So we had to start again with new services, that were routed in at the back of the property, so as not to impact on the Georgian front elevation. Both households were essentially starting with a blank canvas and put in completely new plumbing and gas boilers. We called our plumber ‘Danny the ferret’ because of his ability to get into impossible spaces and never leave a mess. The small new gas boiler could now heat our now separate property in less than an hour; like a Ferrari, able to go from 0 to 60 in 5 seconds. 

Little did we know then, but Danny did such a great job on the pipework and radiators that when last year we had an air-source heat pump fitted, the plumbing through the house turned out to be fit for purpose (big enough pipes in the right places). No new copper piping required except to connect the new equipment, and only one third of the double-panel (with fins) radiators he fitted needed fattening a little to be replaced by triple-panel radiators.

Exploring opinions on heat pumps

While I am no laggard, I’m also generally not an ‘early adopter’ of anything, even when I believe its the right thing to do. It took me a decade longer than most to switch from a film to a digital camera because I was unconvinced they were good enough. I tend to prefer for others to learn the lessons and pass them on. I like it also when there is an inevitable reduction in costs as a market matures a little. So I did get a digital camera finally, 20 years ago now, and it’s been great, but I was hardly an advocate for ‘new tech’.

My old friend Chris runs a successful business, Yorkshire Energy Systems (YES), installing solar and heat pump systems (amongst others), and had already been giving me an education on heat pumps.  I thought we should consider one when we had to replace our existing system, but again, I was in no rush, I needed time to explore the subject.

I invited Chris down to Nailsworth to give a talk to the local climate group I helped run (Nailsworth Climate Action Network), and also invited leaders of local political parties of all persuasions from the Stroud Valleys, including the then MP for Stroud, David Drew for Labour, and the prospective Conservative candidate, Siobhan Baillie (who in a subsequent election became our MP). 

The talk went down extremely well – Chris is a brilliant speaker.

Chris later gave another talk for us online during Covid. This also went down well and was recorded, then posted on our website: What if we could all heat our buildings with renewable technologies? It addresses most of the myths you hear about heat pumps, and a number of people have told me how it helped make up their mind, and go for a heat pump.

I have a good natural science background, so I was not in any doubt about the soundness of the 19th century physics that underpin the workings of a heat pump, which we all blithely rely on every day (most people have a fridge, which pumps heat from inside the fridge to its outside). But understanding the science is rarely enough, even for ex-scientists!

While in one ear Chris was telling me that any building that can be heated with a gas boiler can be heated with a heat pump, in the other ear, other friends, including experts in insulating old buildings, told me that ‘deep retrofit’ was an essential precursor to heating an old building with a heat pump, especially an air-source heat pump. Doubts crept in.

I also cannot have been totally immune to the drip drip effect of reports on the BBC and elsewhere. Heat pumps were first demonstrated in 1830 and the theory was in place in 1852 [Note 2], yet this is what Roger Harrabin said in a 2014 report on a water-source heat pump installed to heat the historic house of Plas Newydd in Wales (science facepalm warning):

It’s barely believable that this sea water has enough heat to warm anything, it’s pretty chilly at this time of year, but yet, thanks to an extraordinary technology called a heat exchanger, it’s the sea that’s going to heat this house.

But cold water contains enormous amounts of energy. Thermal energy is just the jostling of molecules. So the water Roger Harrabin was feeling, say at 7°C, is a sweltering 280 Kelvin (on the absolute temperature scale), with no shortage of jostling molecules from which energy can be extracted. Similarly for air. If you stand in front of an air-source heat pump the air blown out is colder than the surrounding air by a few degrees, because the heat pump has extracted thermal energy from it (using the same tech that a fridge uses to extract thermal energy from anything you put in the fridge). This is more than enough to heat a home.

Yet journalists and commentators have continued to assert that heat pumps can’t heat older buildings without substantial insulation work. Our national broadcaster (the BBC) is culpable, despite its duty to “inform, educate and entertain”. Most recently, during the 8th March 2023 episode of Jeremy Vine’s BBC Radio 2 programme, the host expressed dismay that a radiator was lukewarm. What hope is there when a key programme is failing to “inform and educate” in this way. A hint: it is the thermometer in the room that tells how warm the room is, not any preconceptions on how hot a radiator should be.

Roger Harrabin, Jeremy Vine and many others in the media do a great disservice by sharing their incredulity, and repeating unfounded beliefs about heat pumps.

Why did we decide to go for it?

For us there was a stark choice we faced that forced us to stop vacillating, and certainly stop listening to the naysayers:

  • Firstly, the 25 year old gas boiler was creaking and behaving a bit oddly even after a service. There was no ‘ripping out’ as the tabloids and others emotively campaign against, merely the natural end of life that could no longer be serviced to stay in operation much longer.
  • Secondly, I had seen the data from the Energy Saving Trust, and it was quite clear that getting off using gas to heat our home and replacing it with a heat pump would massively reduce our annual carbon footprint (as I wrote about in Are Air Source Heat Pumps (ASHPs) a Silver Bullet?). This is true even after allowing for an electricity grid that was not yet fully powered by wind, solar and other alternatives to fossil fuels. As a family who wanted to do their bit to reduce the impact of our household on global warming, this was a pivotal moment. If we didn’t take the plunge now, we’d be locking in a high carbon footprint for another 20 or so years with a new gas boiler.
  • Thirdly, the idea that we must carry out extensive insulation (as the The Retrofit Academy claims) before even considering a heat pump, was simply impractical.  Even if we could have afforded the eye-wateringly expensive costs of ‘deep retrofit’, Listed Building approval would not have been forthcoming. Imagine wrapping this Georgian splendour in external wall insulation, or removing coving and panelling to somehow fit internal wall insulation.
  • Finally, at the time, the domestic Renewable Heat Incentive (RHI) was still available but due to close at the end of March 2022, so we needed to get a heat pump system in by then if we were to benefit from the scheme.

Going for it – plans and preparations

So we made the decision in July 2021 to ‘go for it!’. I prepared an outline plan, checklist, questions, etc. We wanted to do it right first time.

I prepared a plan of the house showing the floor area and volume of each room, existing radiators, etc. We bought seven digital thermometers to distribute around the house to ‘benchmark’ how it behaved with the existing gas boiler. I did calculations using current bills and ‘what if’ estimates of future gas and electricity prices to determine whether we would break even on running costs. I remember saying to my wife “gas prices are likely to go up faster than electricity prices sometime in the future. So while our running costs may struggle to compete with cheap gas today, with the current ratio of units costs, that’ll change sooner or later, as the grid gets greener”. Little did I know then that a combination of Putin and a super efficient heat pump would make it sooner, not later.

The biggest challenge was our living room with its large bay window – a thing of beauty but also a significant challenge in terms of heat loss. When the sun is up, even in winter, the room receives a lot of extra warmth (so-called ‘solar gain’), but when the sun goes down, we have to use shutters to reduce heat loss. Not ideal, but sometimes compromises have to be made.

The project forced us to finally clear out the loft. About 100 boxes from our two daughters and us needed sorting, many unsorted from when we had moved in 1998! After several dusty visits to the loft we cleared it, cleaned it, then beefed up the insulation with 300mm depth of Knauf insulation rolls.

The first thing to be grateful to the heat pump for is that it forced us to clear the loft when in our late 60s, rather than having to face it in a decade or two when our knees will have gone. It was such a relief, I can’t tell you.

We had already done what we could to reduce draughts. Our beautiful sash windows could not be replaced even if we’d wanted to. When we had a major servicing job done on them (thanks to a local firm Simply Sash Windows with expertise in historic buildings). We had discreet brushes fitted that paid back immediately with a significant reduction in draughts (when our local climate group did a local ‘retrofit fair’ we included short video snippets on our website to explore options, such as for draught proofing).

For other homes and householders there may be good reasons for carrying out more extensive insulation and other ‘retrofit’ measures. However, bear in mind that if the objective is to get off gas, and thereby reduce your carbon footprint significantly, you really should leave enough in your budget to finance a heat pump system. I discussed this in an essay Insulate Britain: Yes, but by how much? that has attracted a fair amount of mostly positive attention.

For building regulation reasons when we took on the property, we’d had fire strips with brushes fitted around existing internal doors, and it turns out this was very helpful in reducing the turnover of air in the house, and so reducing heat loss.

We contacted two companies specialising in heat pumps. My old friend Chris’s company YES in Yorkshire, and a local company CEG (Cotswold Energy Group) which was recommended to me by a customer of theirs in Nailsworth. Both firms have a proven track record of installing high quality systems (my research assured me). 

We had approval from the Listed Building Officer in August 2021 to proceed, based on outline plans I submitted for locating the external unit well out of sight at the rear of the property. The new services we got installed 25 years ago ran up the back of the building and into a boiler room that could be repurposed for the internal units required for the new system. We had a few lucky breaks like that. The new hot water tank would just fit. Another lucky break.

The surveying of the house is a crucial stage in the process and ought to be whatever heating system is installed. Overall, these were the checkpoints I ticked off on the project prior to installation:

  • Listed Building approval ✔︎
  • Electrical ‘load survey’ and mains fuse; existing 80 Amps would be fine ✔︎
  • Water pressure checks ✔︎
  • Sizing of pipework in the house ✔︎
  • Cleared loft and installed new beefed up insulation ✔︎
  • Sorted out draughts in windows and doors ✔︎
  • EPC certificate ✔︎
  • RHI requirements met ✔︎
  • Check by installers of suitability of platform outside for external units ✔︎
  • Check space inside for internal units ✔︎

We were now ready to proceed and made our requirements very clear. For example, I said I was not interested in a hybrid system with gas as a backup; that seemed a bit like buying a petrol car in 1910 and having towing arms for a horse, just in case. A few people tried that, but it didn’t catch on.

The instructions was clear: size the system properly to meet our requirements and those of any subsequent owner (including one who might have 4 teenage children who shower a lot).

The two quotes were very similar in terms of proposed design and costs. In the end, we felt that everything else being equal, going local swung it, in case we needed any call outs to sort out teething issues and future servicing. Chris felt this was an important factor to be taken into consideration.

System design

With a big enough heat pump you can heat any building that a gas boiler can heat. Geneva City Hall has been heated by a water-source heat pump since 1928, and a large air-source heat pump at Hillpark Drive, Glasgow has been heating 350 homes since 2017.

The system design followed MCS standards (Microgeneration Certification Scheme), which stipulates that the system should be able to achieve at least 21°C in living rooms, 18°C in hallways and bedrooms, and 22°C in bathrooms; and be able to do this on the nominal coldest day of the year for your location. For our system and location, that meant that the heat pump itself, and radiators, were sized to achieve these targets with a flow temperature of 50°C, when it was -1.6°C outside. The ‘flow temperature’ refers to the temperature of the heated water pumped to the radiators.

It is crucial that the assessment is done room by room. If just one large room has an undersized radiator, the room may not reach its desired temperature at the expected flow temperature, undermining expectations, for no fault of the heat source itself.

The heat pump itself must be able to achieve the peak heating demand for the whole house.

Because the largest heat pump available at the time was just short of the peak demand estimated for our home, we ended up with a so-called ‘cascade’ system, with two smaller heat pumps working in parallel, in conjunction with a buffer tank. In total, it had more peak power than we needed, but not so much as to cause an issue.

In a way, the cascade system turned out to have the benefit that when it was comparatively warm outside, only one of these units needs to be in operation at any time. The clever electronics made sure that each one shared the work equally over the year.

The only issue was that both firms were maxed out with work because others like us were trying to get things done before the end of the Renewable Heat Incentive (RHI). In addition the Covid pandemic had disrupted supply chains for heat pumps, like everything else, so kit was also scarce.

The installation

Consequently, the installation was finally done at the start of December 2021, taking just over a week. It was a larger than normal system for a larger than normal house, but the principles are the same, whatever the property.

The twin Mitsubishi Ecodans were placed on a platform we created outside the old boiler room:

The new internal setup looked as follows:

You may think that this looks complicated, but it is not a complexity that you need to deal with or even to understand, any more than you need to understand how a modern car works. In many ways, the increase in sophistication of systems (be they cars or heat pumps) reflects their ability to be ‘easier to drive’, extremely efficient, environmentally aware, and with very little in the way of maintenance to worry about. Hardware and software combining forces!

The installation process went as follows:

  • Introduction to installation team, and logistics agreed
  • Old gas boiler and tank removed
  • Existing pipes and radiators flushed
  • Heat pump and other kit moved into position
  • Plumbing in of kit (heat pump, hot water tank, etc.)
  • Plumbing in the few new radiators required 
  • Heat pump connected to electrical power
  • Control system system installed 
  • One wireless thermostat placed in living room, set to 21°C
  • Various control setups competed
  • Setback thermostat by 3°C to 18°C between 10pm and 6am
  • Weather compensation setup
  • System put into operation
  • Radiators ‘balanced’ to ensure optimal heat distribution
  • Metering installed for flow/return heat and electricity usage
  • Certificates produced for MCS compliance

In addition to the assessor/ designer who did the design we had two plumbers who did the physical work and ‘plumbing in’ of the new kit, followed by an electrician who did the setting up of the heat pump (see ‘The Team’, Note [3]).

As it turned out, only on a few very cold days (in practice, a minimum of -5°C) did the flow temperature ever get as high as 50°C (the maximum design ‘flow temperature’ for our system). The flow temperature is best kept as low as possible, while still doing its job (see Note [4]).

The results

So how did things turn out?

We get the space heating we need and plenty of hot water. Our hot showers have never been better. We have bills that of course have gone up due to the energy crisis, but less than they would have done if we’d stayed on gas.

A key measure of the success of a heat pump installation is the performance it actually achieves in practice – as opposed to some published figure that assumes an idealised situation.

For any heating system one needs to think of the performance of the whole system. In addition to the heating system, there are the radiators and fabric of the building, because it is all these together that determine how efficiently rooms are maintained at a desired temperature.

For our heat pump, performance was assessed using the ‘seasonal coefficient of performance’ (or SCOP), which is the heat energy delivered during the year (in kilowatt-hours (kWh)) divided by the electrical energy used by the heat pump (in kWh).

For our system, the SCOP achieved in the year to March 2023 was 3.3, or 330% in percentage terms; pretty impressive I feel. That means that for every 1 kWh of electricity we put in, we get 3.3 kWh of heat out of the heat pump (2.3 kWh of this is harvested from the ambient air). By comparison, the old gas boiler was only 72% efficient, meaning that for every 1 kWh of primary energy in the gas put in we got 0.72 kWh of heat out.

This means that even though the unit electricity price is greater than the unit gas price by a factor of over 3, this is more than offset by the relative performance of the new heat pump compared to the boiler it replaced. So our running costs are less by comparison.

This result is totally at odds with the naysayers we hear incessantly in the media that they are difficult to install, won’t work on older buildings without substantial insulation measures, or will cost a fortune to run. None of this received wisdom has been true in our case.

Our experience is in line with the Catapult study (2021/22) that concluded that All housing types are suitable for heat pumps, finds Electrification of Heat project

The project has not identified any particular type or age of property that cannot have a successful heat pump installation. The suggestion that there are particular home archetypes in Britain that are “unsuitable” for heat pumps is not supported by project experience and data.

So I don’t believe our experience is in any sense exceptional or to be treated as anecdotal. Rather, it demonstrates that even in a building that is ‘hard to treat’, as the experts would call it, there is no reason an air-source heat pump cannot be successfully installed and operated, with a little care and preparation.

I hope that our story provides an illuminating corrective to the media naysayers, and others who should know better.

If it gives encouragement to those wishing to get off gas for whatever reason, it will have done its job.

If you are doing it to lower your carbon footprint, then whatever your lifestyle, it will be one of the most impactful decisions you will ever make in your lifetime.

© Richard W. Erskine, 2023

If you liked this essay, you might also be interested in Insulate Britain: Yes, but by how much?



[1] Burning Questions (and Answers)

Q. So can you really heat a large old house with an air-source heat pump, without ‘deep’ retrofit?

A. Yes

Q. But does it cost more to run than than if you’d stuck with a gas boiler?

A. No,  comparatively it costs less. Of course, gas and electricity unit prices have both gone up, but gas proportionally more and the efficiency of the heat pump trumps the differential in electricity-to-gas unit price. See Will my heating bill increase if I get a heat pump? another essay I have written, where I show this in detail.

Q. But it’s really expensive to install surely?

A. It costs less than a new kitchen that is mostly MDF and air, and yet we all seem happy to pay for a new kitchen that the next owner of the house will quite possibly “rip out”. The heat pump will probably last for 25 years and will over its lifetime save you more in carbon emissions than anything else, for a typical householder at least 3 tonnes of carbon dioxide per year compared to gas with the electricity grid as at present (and even more as the grid gets greener). Octopus Energy are creating a market for a low cost heat pump installation, that may meet the needs of a majority of householders, if not outlier cases such as mine.

Q. But can we go green using biogas?

A. Burning stuff is so last century! And as Prof. David Mackay said, if you have some gas it is much more efficient to send it to a gas turbine to create electricity to power a heat pump in your home than to burn the gas in your home. The same would be true of biogas, an idea that has been heavily criticised by independent expert Dr Richard Lowes , and flies in the face of the clear recommendations of the Climate Change Committee, see Note [6].

Q. Should we hold on for hydrogen boilers?

A. No. Using ‘green hydrogen’ from excess renewable electricity to make hydrogen to burn in our homes would require 6 times as many wind turbines than if we simply sent the electricity direct to home to power heat pumps. Hydrogen will be in demand in hard to decarbonise sectors including fertiliser production, etc. Anyone who gets a hydrogen boiler will be locked into expensive hydrogen. The Climate Change Committee expect hydrogen to play only a niche role in heating (see Note [6]).

Q. Did you have to change all your radiators, and pipework?

A. No. The pipework did not need changing and only 1/3rd of the radiators needed fattening a little (from 2-panel to 3-panel); their width and height were unchanged.

Q. Is it noisy?

A. Not at all, even standing close by. If birds are singing you can’t hear it at all.

Q. Can it heat hot (tap) water?

A. Yes. It does that in shortish bursts, and because the hot water tank is under mains pressure, the showers are now much better.

Q. Does it use an immersion heater some of the time?

A. Not for day-to-day water heating. It does use an immersion heater periodically to boost the tank’s temperature from 50°C (the target temperature, achieved with the heat pump) to 60°C (required to kill the organisms); no point flogging the heat pump for this little job. This deals with the risk of Legionella, which is a requirement under current regulations (even though the sealed nature of the system makes it an extremely low risk). In any typical month, the legionella ‘purge’ occurs only for a few hours overnight every two weeks. It has very little impact on the measured performance or the heating bills.

Q. But my plumber said you can’t get the water hot enough?

A. Untrue. Because who wants the hot water from a tap to be more than the new building regulation of 48°C, which a heat pump can easily achieve. Why would we want young or older relatives and visitors to scold themselves?

Q. My plumber also said that radiators never get hot enough?

A. Your plumber is mistaken. Again the new building regulations (whatever the source of heat) are that the ‘flow’ temperature should not exceed 55°C. If your room needs to get to 21°C say, then (depending on the external temperature) you may only need 35°C, 40°C or 50°C (in the most cold days), to get the room to 21°C. Not as fast as if the flow temperature was 75°C, but just as assuredly, and more cost effectively. Your skin temperature is say 34°C, so a radiator at 40°C or even 50°C might feel lukewarm, but that is irrelevant. It’s what the thermometer on the wall says that counts. Don’t touch, look!

Q. Was the project disruptive?

A. Not the fitting of the heat pump, which took just over a week. For us, the most challenging thing was clearing the loft, in order to increase the loft insulation to modern standards, and get the grant.

Q. Do you have smart controls around the house?

A. No. A well designed system (whatever the source), which includes properly sized radiators and weather compensation, will always ensure that if the single thermostat in your living room is reading the target temperature there, the other rooms will also be at their target temperature. No fiddling with controls in rooms or zones. By keeping it simple in this way, we actually can forget we have a heat pump at all. It works reliably, without us ever having to fiddle with any dials or thermostats. We just let it do its thing.

You will have many more questions no doubt, but these are typical of the ones people raise with me, so I hope the answers have proved illuminating.

[2] History of heat and heat pumps

19th Century scientists developed the ‘kinetic theory of heat’.

They established that ‘heat’ in substances was no more than the jostling of molecules, and the higher the temperature, the greater the average speed of their jostling. Not only that, but that this jostling only ceases at ‘absolute zero’, which is -273.15 degrees on the Celsius scale. So the water Roger Harrabin was feeling, say at 7°C, was a sweltering 280 Kelvin (the name subsequently given to this new scale). No shortage of jostling molecules from which energy can be extracted. A balmy -5°C for winter air passing through an air source heat pump – no problem – it being a balmy 268 Kelvin.

As has been noted:

The first working compression–expansion refrigerator (or heat pump) was built by Jacob Perkins in the 1830s. William Thomson (Lord Kelvin) first proposed using heat pumps for space heating in 1852.

For those interested in learning more about the history, Boltzmann’s Atom: The Great Debate That Launched a Revolution in Physics is a great biography of one the principal scientists who shaped this theory, and fought a long battle with naysayers such as Mach who couldn’t bring himself to believe in the existence of atoms.

[3] The Team, for our project overall were:

  • Senior manager, who provided oversight at every stage to ensure a quality delivery: during assessment, proposal, installation and hand-over.
  • The assessor/ designer. She was in her 20s, a graduate with a 1st Class degree in Geophysical Sciences who’d decided to not go into the oil & gas industry, and instead become a heat pump consultant. She did the surveying of the property, estimating heat loss for every room, and preparing a detailed design and costing for the system.
  • There were two plumbers who did the physical work, both young (also in their 20s). They first removed the existing boiler and hot water tank. They then got the units in place on the day, including a heat pump (actually two in our case) that had to be lumbered up a steep path to reach the back of the house (built into the side of a hill); a hot water tank; water pumps etc. They then connected all the pipework to the units. Because they were part of a team, these plumbers didn’t need a deep knowledge of heat pumps, just the principles of low flow temperature systems. They drained and flushed the existing plumbing in the house, and found no issues with it holding the slightly higher water pressure needed for a heat pump. Only a third of the radiators needed up-sizing to triple panel ones – and given all the dire warnings I’d heard (false as it turned out) I was pleasantly surprised by this. Once the system was operating, they ‘balanced’ the system, so heat was as evenly distributed as possible.
  • There was one electrician, who not only did the electrical connections, but also setup the controls for the heat pump(s). The so-called ‘weather compensation’ is a crucial part of the setup, as it optimises the efficiency of the system. The temperature of the water being pumped around the radiators is kept as low as needed to deliver the space heating. We also decided to have the heat pump on continuously but set back a few degrees at night. This meant that the heat pump was not having to work too hard in the morning to reach the target temperature in rooms. With our thick walls, it would not be a good idea for these to cool down too much. Paradoxically, we use less energy this way than if the system went off completely over night.

I explore the question of how we scale up capacity in heat pumps in How hard will it be to scale up heat pump capacity in the UK?, another essay of mine.

[4] Flow temperature is best kept as low as possible, that does the job

The larger the surface area of the radiator, the lower the flow temperature needed to deliver the required amount of heat. This is why underfloor heating is often able to operate at a mere 35°C. But even for a system like ours, the flow temperature can be relatively much lower than expected. For example, in the last 7 days, the external temperature has ranged from 8°C to 11°C, and the flow temperature has never exceeded 36°C.

Which is why the talk of ‘high temperature heat pumps’ to deal with difficult buildings strikes me as a non sequiter.

In any case, building regulations that came into force in June 2022 in the UK mean that all new systems must have a flow temperature no higher than 55°C, whatever the heat source, so those trying to flog high temperature heat pumps are barking up the wrong tree in my view. 

Just design the low flow temperature system properly. Job done.

[5] Performance of air-source heat pump based system

The performance for the system relates to the heat pump, radiators and the fabric of the building itself. Any one of these can influence how good the measured performance is. The performance over a given period (say a day) is calculated as the ratio of the heat energy that the system delivers (in kilowatt hours, kWh), and the electrical energy used by the system (in kWh). Because a heat pump harvests energy from the ambient environment (air, ground or water) warmed by the sun, the performamce will be greater than one (or 100%).

For space heating the performance gets less the greater the difference is between the outside temperature and the required internal temperature. We follow a common practice of calling the performance measure the ‘coefficient of performance’ (or COP) and over a whole year, calling it the ‘seasonal coefficient of performance’ (or SCOP).

A 2013 Study by Energy Saving Trust – – reckoned that the SCOP for an air-source heat pump is typically 2.5 (or 250%), but as we have seen, it is more common to get a SCOP of over 3 (300%) in 2023, using a modern heat pump and practices.

But what about the daily performance? Well, for our system, even when it was -5°C (colder than the nominal coldest day -1.6°C) the daily COP was 2.1 (210%) and over the year, the daily COP got as high as 5.4 (540%).

The SCOP we achieved of 3.3 (330%) was extremely good, in our view.

Another way to measure performance is the kilowatt hours required to heat one square metre per annum (kWh/m².a). The average British home needs over 130 kWh/m².a, but a new house built to Passivhaus standards would need just 15 kWh/m².a. The Association of Environmentally Conscious Builders aim for 50 kWh/m².a when doing retrofit on existing buildings, with a “certifier approved exemption” 100 kWh/m².a for difficult older buildings. Their standards for doing retrofit can be found here:

Our building was using 154 kWh/m².a to heat the house when using the gas boiler. After modest retrofit ‘fabric’ measures and moving to the air-source heat pump, the demand has reduced by about 25% to about 110 kWh/m².a (not far off the AECB higher “exemption” of 110 kWh/m².a, although I should stress we have not asked an AECB member to review our fabric measures). I somehow doubt this 25% reduction is due to the fabric measures alone (loft insulation and some draught measures). I am convinced that the gentler heating with the heat pump (rather than the wild swings we had with the gas boiler) gives rise to a lower energy demand overall.

[6] Heat pumps will be primary tool in decarbonising heating

The Committee on Climate Change (CCC) in their 6th Carbon Budget stated (based on very detailed modelling of scenarios, costs and risks):

‘By 2030 37% of public and commercial heat demand is met by low-carbon sources. Of this low-carbon heat demand 65% is met by heat pumps, 32% district heating and 3% biomass. By 2050 all heat demand is met by low-carbon sources of which 52% is heat pumps, 42% is district heat, 5% is hydrogen boilers and around 1% is new direct electric heating.’

Other experts agree. LETI conclude that heat pumps are a far superior option for home heating than hydrogen; see their report Hydrogen: A decarbonisation route for heat in buildings?”, LETI, February 2021


I’d like to thank my old friend Chris Wilde, who is Managing Director of Yorkshire Energy Systems (YES), for educating me on heat pumps over the last few years, and showing me the art of the possible. Always witty and wise, I have learned so much from Chris.

Also, thanks to the team from Cotswold Energy Group (CEG), who were very professional at all stages in the project. I’d like in particular to thank Zoe Phillips for her advice and support.

Thanks to Marilyn, my wife, for reviewing the essay and providing improvements, but most of all, for being my companion on this journey.

Any errors in the essay are all mine.


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Will my heating bill increase if we get a heat pump?

I was asked this question by a householder who is in the process of considering making the switch from a gas boiler to a heat pump, in part due to a desire to reduce their carbon footprint. After an exchange where I learned their current situation and thoughts, they asked:

One thing that keeps going through my mind are the electricity costs for the heat pump. We are billed for 40,000 kWh of gas, which is a lot. How much would it cost us for the electricity to run a heat pump?

Also, can we install a solar PV system that would be able to generate at least some of the electricity we need?

I replied as follows:

“It depends in part on the extent of the fabric measures you do implement, although I understand that you have decided not to execute the ‘deep retrofit’ that an architect recommended due to the huge cost, for your 17th Century home. Can I just make it clear that your architect is ill-informed in saying that deep retrofit is essential before you consider a heat pump.

No change in heat demand

“Let’s assume your current gas boiler has been operating at 80% efficiency.

That means the actual current delivered heat energy is 0.8 x 40,000 kWh = 32,000 kWh, which is then the actual heat demand! (You say that the bulk of this is on space heating, so I am ignoring the complication of the split in energy use between water and space heating, for simplicity).

Let’s assume in first instance that you don’t reduce this amount in the short term (through insulation etc.), in order to make a like for like comparison.

Let’s also assume that you achieve a SCOP (Seasonal Coefficient of Performance) of 3 (by the way, my listed house has a predicted SCOP of 3.6, so better than 3. So, for the calculation below, this can be regarded as a conservative estimate, as long as your system is professionally designed and installed; and remembering that the system as a whole may require some radiators to be upgraded).

That would imply the amount of electrical energy required would be 

= 32,000/ 3 = 10,700 kWh (rounded up)

I am going to use capped prices (as at Autumn 2022) to get a ‘worst case’ for you at least this winter.

At the current capped rate of 34p/kWh for electricity this would mean an annual cost of

10,700 kWh x 34 p/kWh = 363,800p = £3,638 using the heat pump system

The cost of using the current boiler, with 10.3/p/kWh for gas, would be:

= 40,000kWh x 10.3p/kWh = 412,000p = £4,120 using the gas boiler.

This calculation (with its assumptions) implies that the running costs would be less for the heat pump than with the gas boiler.

This might at first surprise you given the higher unit cost of electricity, but it rather demonstrates the impact that much higher efficiency has on running costs.

Obviously, this will change if/ when the unit prices change, but not necessarily in a bad way. If, as has been muted, electricity costs from renewables are decoupled from the costs of gas station generated electricity (which is dependent on world market costs, which then tends to drive up the costs of all domestically generated electricity irrespective of source. Then in future, we could see a drop in electricity, and this would be a progessive reduction as the grid gets greener and greener over time). “

After fabric measures

“It would also be different if – as would be prudent – any measures are undertaken like loft insulation to reduce heat demand. You said you planned some measures. As my essay explained, there is a trade-off between insulation (and other fabric measures) and a heat pump, which depend in part on your overall retrofit budget. All I suggest is that you leave some money in the pot to get a heat pump, but that’s not to say that fabric measures are not important, far from it.

Suppose that following loft insulation and other fabric measures you decide to implement, the actual heat demand of 32,000kWh was reduced by 20%, to 25,600kWh.

With the same SCOP, that would imply the amount of electrical energy required would be

= 25,600/ 3 = 8,500 kWh

At the current capped rate of 34p/kWh for electricity this would mean an annual cost of

8,500 kWh x 34 p/kWh = 289,000p = £2,890 using the heat pump.”

With domestic solar PV

“Solar energy peaks in summer whereas heating requirements peak in winter (but both are middling during Spring and Autumn, the ‘shoulder’ months). Nevertheless, one could reasonably expect – thanks to the ‘shoulder’ months – that the home grown electricity would reduce the heat pump running costs by roughly 25% (only a professional house survey, taking into account the orientation of panels, tree shading, etc., would answer this question precisely).”


“With your current gas boiler your annual heating costs are: £4,120

With a professionally designed and installed heat pump system and no insulation measures your annual running costs should be no more than: £3,638

With a 20% reduction in heat demand following cost effective insulation/ draught proofing, the heat pump annual system running costs would be: £2,890

With solar PV, let’s assume a further reduction in costs of 25% giving the heat pump system annual running cost of: £2,168

I hope that helps.”

(c) Richard W. Erskine, 2022


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If we can’t stop flying, can we at least stop lying … to ourselves

“Flying is only 2% of global emissions, so it’s ok to fly.” That’s what I heard from a neighbouring table in a restaurant. I didn’t have the heart to lob in a comment “Yeh, but I bet it’s not 2% of your emissions!”

The Oxfam Extreme Carbon Inequality report [1] showed that top 10% by income were responsible for 50% of emissions and bottom 50% were responsible for just 10%, so averages such as that 2% figure can conceal some important truths and not a lttle of moral hazard.

The significant warming that the planet is experiencing [2] is thereby much more of an issue currently of high consumption in the West than population growth in the global south.

We can quite easily get a feel for the numbers.

Let’s start with averages

The world emits about 40 billion (giga) tonnes of carbon dioxide a year (or 40 GtCO₂/yr) from burning fossil fuels [3].

We have a world population of about 8 billion, so the average CO₂ emissions per person is 5 tonnes of CO₂ a year (5 tCO₂/yr).

2% of that figures gives 0.1 tCO₂/yr.

Time to relax?

So what about the average flyer?

2% of 40 GtCO₂/yr is 0.8 GtCO₂/yr, or 800 MtCO₂/yr.

A Smithsonian Mag article [4] estimated that only 6% of the world’s population flew in any one year; 6% of 8 billion is 480 million people.

If we share out the 800 MtCO₂/yr of flying emissions amongst those 480 million in any year, we get 1.7 tCO₂/yr per person. Given that a UK to Madrid flight is estimated as 265 kgCO₂ (0.265 tCO₂) [5], it shows the impact that longer journeys and frequent flyers are having in pushing the average up to over 6 times this number.

Needless to say 1.7 tCO₂/yr is nearly 40% of the world’s average per person total footprint, not a comforting 2%.

What about the UK?

Pre-COVID figures suggest that nearly 50% of UK citizens fly at least once per year, and flying accounts for 7% of the UK’s emissions. However, 1% of UK residents were found to be responsible for 20% of overseas flights [6].

It gets worse

The emissions from flying become stacked higher and higher with increasing income. The top 1% globally emit a staggering 7,500 tCO₂/yr, and are responsible for half of the world’s flying emissions [7].

The takeaway message

Let’s not kid ourselves that our flying emissions are ‘small’. In the UK they are on average 7% of our CO₂ emissions but the actual emissions increases in line with our consumption, which tends to correlate with incomes.

The case for a fair system that does not penalise the least well off, and has an escalating frequent flyer levy, is now undeniable. It needs to be sufficient to disincentivise frequent flying. Whereas the incentives today are completely the opposite. Airlines reward frequent flyers with gold membership cards, priority boarding, deluxe lounges and streams of offers.

As more people in the world gain access to flying, and as the relatively easy-to-decarbonise sectors (like cars and heating) are dealt with, the percentage of emissions from flying – however you wish to measure it – will only grow.

I’m not going to tell anyone “don’t fly!”, how could I? When I was working as a consultant until my retirement in 2016 I was making 10 to 15 flights a year. I’m in no position to preach to anyone. But we have all been in denial about flying, myself included, for too long.

If we can’t stop flying, can we at least stop lying … to ourselves!

(c) Richard W. Erskine, August 2022.


  1. Extreme Carbon Inequality, Oxfam,
  2. IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 3−32, doi:10.1017/9781009157896.001.
  3. See Figure SPM.4(a) in Reference [2]. This does not include the contribution from other greenhouse gases that currently make a lower but still very significant contribution as shown in Figure SPM.2 in Reference [2].
  4. How Much of the World’s Population Has Flown in an Airplane?, Christine Negroni, 6th January 2016,
  5. Climate change: Should you fly, drive or take the train?, BBC, 24th August 2019,
  6. 1% of English residents take one-fifth of overseas flights, survey shows, Niko Kommenda, 25th September 2019,
  7. 1% ‘super emitters’ responsible for over 50% of aviation emissions, Andrew Murphy, Transport & Environment, 3rd December 2020,


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“Stuff & Nonsense” confronts climate change

One would like to imagine that Middle England might have woken up to the reality of climate change with ever more frequent heatwaves (not to mention flooding), but judging from the latest screams of derision from the usual suspects at the warnings of imminent heat stress, it’s hard to tell.

So, how do we navigate the conversation on climate change during a heatwave? 

How do we make the link between the latest extreme heat wave to climate change when we have been telling people for years that weather extremes are not to be confused with the long term trends associated with climate change?

For example, in situations such as when a US Senator held up an unseasonal snowball to ‘demonstrate’ there is no global warming, he was rightly reminded of this distinction.

I’ll get back to these questions. I wanted firstly to illustrate the challenge we face in trying to have a conversation with the doggedly unconcerned.

Stuff and Nonsense

I overheard someone in a delicatessen yesterday joking about “hilarious” letters in The Times, writing on how we didn’t need extreme weather warnings back in 1976. 

Can’t we just enjoy it? 

Chuckle, chuckle. 

Bloody nanny state. 

Helloooo … It’s called summer!

What’s the world coming to?

I wanted to ask if she knew that there were 70,000 excess deaths across Europe during the 2003 heatwave, and that just this week fires have been raging across Europe, from Portugal to Croatia, devastating many communities.

I resisted the temptation.  No, I chickened out.

It reminded me of the ‘stuff and nonsense’ sketch French & Saunders did some years back satirising Middle England’s perpetual angst over our alleged nanny state (you know, the one that gave us food banks, Grenfell, and a host of nannyish things). 

The sketch – which I cannot find on YouTube – had two portly conservative stalwarts trying to outdo each other with stories of how much pain they have endured without needing to call a doctor. Shotgun accidentally blew my foot off … ha, ha, ha, no problem!

bloody bed-wetters these days …. 

… stuff and nonsense.

It’s really no different to the ‘Elf ’n’ safety’ campaign Richard Littlejohn, Boris Johnson and others have pursued over many years in their toxic opinion pieces in the Daily Mail, Daily Telegraph, and elsewhere. This is now firmly embedded in the psyche of Middle England and a favourite source of jokes at Conservative Party conferences.

Extreme weather and climate change

Yes, we did have a very hot summer in 1976, but what does that prove? 

Whataboutery only proves that the speaker has no ideas and no grasp of the evidence.

The truth is that as with a progressively loaded dice, the odds keep changing. This is the latest from the MetOffice [1]:

“We found that in just two decades, the probability of seeing those record breaking 2003 temperatures again have become more than 10 times more likely.”

And the chances will keep increasing. Warnings like this are not new. Dr Peter Stott from the Met Office wrote in 2014:

“Updated model projections of future changes suggest that by the end of the century summers as hot as 2003 will be considered unusually cool.”

That is no longer exceptionally hot, but exceptionally cooler than the new normal.

Think about it.

The odds have increased because of our human emissions of greenhouse gases, principally carbon dioxide from fossil fuels. The odds get worse with every year we continue to emit the stuff.

I don’t think our progeny will be chuckling away in 2100 at anti-woke opinion, just despairing at the obdurate ignorance of those led us to this place.

The language of weather and climate

The British have a very well developed language of weather, which suffuses our every day encounters, our poetry, our paintings and our culture generally.

Surrounded as we are by a warm ocean, a cold pole, a European continent and, from below us, the Mediterranean and Saharan land mass, our weather can seem unpredictable.

We are less articulate when it comes to climate; barely literate.

But we have been told not to confuse weather with climate. Climatologists customarily defined climate change as a trend that could be discerned over a few decades, not a few days. 

This makes it hard to talk about any one particular event – such as the 2003 heatwave – and put it down to climate. This was a godsend to climate change deniers, who like tobacco companies before them would make the defence that this person could have got lung cancer anyway (the increased odds don’t prove that THIS person would not have got it anyway).

Of course the counter reflex of claiming that every extreme event is the result of our human emissions doesn’t convince either; our weather variability doesn’t go away in a warming world, it is just gets superimposed on a rising trend.

So, just as a pinball machine on a tilt will still produce apparently random outcomes, the biases formed by the tilt will increase the odds of some outcomes versus others. The UK is getting warmer, and that has consequences as both ends of the hydrological cycle: be it extreme heatwaves or extreme flooding. 

A new science has come to the rescue in our attempts to unpick the apparent contradictions in talking about short term weather extremes in the context of longer term climate change: extreme weather attribution.

Extreme weather attribution

It is now possible for climate scientists to put a number on a particular event and say how much more likely it was as a result of man-made global heating; 20%, 50%, 3000%, or whatever the physics and historical records together show.

This is actually not so new in its general application, as the quotes from the MetOffice above attest to. General retrospective studies on the raised chance of, say, a hot summer across the UK or Europe, have been published before.

What is relatively new is taking a specific event that may be relatively localised and ascribing odds to it, and doing this within a few days of the event occurring; of extreme weather attributions as a service.

Dr Friederike Otto is one of the pioneers of this science and approach. Her book is an unputdownable account of her journey and the implications of this work: Angry Weather: Heat Waves, Floods, Storms, and the New Science of Climate Change, 2020

Speaking of the floods in Germany in 2021 she said [4]:

“These floods have shown us that even developed countries are not safe from severe impacts of extreme weather that we have seen and known to get worse with climate change,”

In May this year, the World Weather Attribution (WWA) organisation issued [5] its analysis of the extreme / early heat wave in Pakistan/ India in early Spring, which they concluded was 30 times more likely (i.e. 3000% more likely) than it would have been without human caused global heating.

A different conversation

So what do I do next time I’m in a queue and I hear someone chuckling at the latest opinion piece in the papers mocking those concerned at climate change and the latest extreme weather event? I might try a gentle question:

“Can I ask why you think there is nothing to worry about?”

This should flush out enough to respond to with the material I covered earlier. 

It’s real, the impacts can be life threatening, and the trends mean it’s going to get more frequent and more intense. One could continue:

“Why does this have to be part of an on-going culture war?  

Why isn’t this something that should unite us, if not for our own sake, for the sake of our grandchildren?

Surely that is no laughing matter?”

. . . o o O o o . . .

(c) Richard W. Erskine. 17th July 2022.

References and notes

 1. ’New study examines chances of record June temperature’, MetOffice, 29th June 2022, 

2. ‘Heatwave increases’, MetOffice, 2014,  

3. ‘Angry Weather: Heat Waves, Floods, Storms, and the New Science of Climate Change’, Friederike Otto, 2020

4. ‘Germany’s deadly floods were up to 9 times more likely because of climate change, study estimates’, Angela Dewan, 24th August 2021, CNN,

5. ‘Climate Change made devastating early heat in India and Pakistan 30 times more likely’, World Weather Attribution (WWA), 23rd May 2022, 

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My Sceptical Friend

How does one speak about climate change to a friend, colleague or neighbour who is not engaged, and sceptical about the need for urgent action?

I was prompted to write this essay because I have been asked this question three times in the last two weeks, and it got me thinking.

In the local climate group I help run, we focus on positive local action. Unlike many climate groups we do not post dystopian images of the latest horror from the front line of climate impacts. This is not because we deny them but because we have found it is not the best way to engage people who are thinking about getting involved, or are avoiding getting engaged! 

They can find the scary material elsewhere, and our job, as a climate group, is to facilitate and catalyse change, through networks, conversations and projects.

But then there are some people – in every community – who clearly do not feel that urgent action is needed. So can we really avoid dealing with those sceptics?

The sceptics we are talking about here do not fit the stereotype of an ideological ‘denier’ – such as Lord Lawson – but they have often heard or read things that reassure them that action is not urgent (‘those alarmists have gone too far!’, they hear, a reassuring salve). Conservative newspapers actively dismiss the need for urgent action. 

So will facts change a sceptic’s mind?

It is well established that while facts are important, a key reason why people believe in certain things is their culture and values (I recommend reading Katharine Hayhoe on this [1]). 

If one group believes in the freedom of communities to do their own thing, free of central Government ‘interference’, there is then a perceived conflict of values with others who favour the need for regulations to promote change. The challenge is to find the common ground, the shared values.

If someone believes that the planet will work things out, with or without our help, they may be quite fatalistic about society’s ability to change ‘there is nothing we can do’. The challenge then is to show how – assuming we had sufficient agency to cause the problem – we also have the ability to prevent the worst happening.

Most people are neither deniers nor fatalists. They want a positive future for their children and grandchildren. If they can see the need for change, they can become champions for change.

Who are we talking to?

It is very easy, especially for those like me who spend way too much time on Twitter, to frame the engagement challenge in terms of those on the ideological right who have made a career out of climate science denial.  That is a mistake in my view.

Various surveys in the UK, USA and elsewhere indicate a growing number that see the need for change. Some just voted in Australia to end the reign of a right wing, climate change denying party.

The UK Government’s Winter 2021 Attitudes Survey showed that 85% of respondents were either ‘very concerned’ or ‘fairly concerned’ about climate change [2].

(Credit: BEIS Public Attitudes Tracker: Net Zero and Climate Change Winter 2021)

Even in the USA, where we are constantly reminded of the polarised nature of political debates, we find that on climate change, there is a majority of people who are either ‘Alarmed’ or ‘Concerned’ (in the nomenclature of the Yale Climate Change Communications ‘6 Americas’ [3]). 

As the authors of this report write:

There has been substantial change in the distribution of the Six Americas over the past five years. The Alarmed segment has nearly doubled in size, increasing 15 percentage points (from 18% to 33% of the U.S. adult population), including an increase of 9 percentage points from March 2021 to September 2021. In contrast, over the past 5 years only about 1 in 10 Americans have been Dismissive (decreasing from 11% to 9%). Overall, Americans are becoming more worried about global warming, more engaged with the issue, and more supportive of climate solutions.

The ‘Dismissives’ are only 9% of the US population, but often appear to be 90% of the commenters on Twitter, Facebook, and elsewhere. That is not a reason for allowing them to frame the conversation in their terms. 

Instead, we increasingly need to get off our computers and have 1:1 convivial conversations in person, over a cup of coffee, at a market stall or over the garden fence, with the majority who are genuinely curious at exploring the issues.

The ‘Why?’ question

Exploring values as opposed to just facts is a crucial part of the conversation. When someone makes a strong, provocative statement, the response should initially aim to explore the ‘why’ rather than the ‘what’:

Why do you feel that?

This might well reveal those values or assumptions that are really at the heart of someone’s feelings, and explain the anger or frustration they express. This is almost impossible to do online.

Those sceptical of the need for change are not solely on the right. There are some environmentalists who have a such a strong preference for nature-based solutions, they will find all the downsides of technological solutions, while being blind to any shortcomings of their preferred solutions.

In fact, we all need to ask ourselves the ‘Why?’ question from time to time, to question our beliefs, biases and assumptions.

A little bit of knowledge can be a useful thing

People new to climate change can be overwhelmed by its sheer complexity, and think they must have encyclopaedic knowledge to engage with people, especially sceptics; they don’t!

It does help to know some key concepts, which can be used to help guide responses to questions. A few are summarised here:

  • Civilisation and agriculture have blossomed since the end of the last ice age with a stable atmospheric concentration of carbon dioxide at 300 parts per million (ppm). In just a short period since the start of the industrial revolution, human emissions have pushed it to over 400 ppm [4]
  • There are many carbon cycles that cover vastly different timescales. Despite large flows of carbon into and out of the oceans, the flows balance each other; maintaining a stable concentration of carbon dioxide in the atmosphere. Humans are now upsetting that balance at alarming speed [5]
  • Carbon dioxide is called a ‘long-lived greenhouse gas’. The raised concentration in the atmosphere (caused by burning fossil fuels) remains raised for a very long time [6]
  • The rise in global mean surface temperatures of about 1.2°C since the start of the industrial revolution is already having impacts, and every 0.1°C of rise on top of that will increase the impacts [7].
  • All societal and personal choices have a carbon impact of some sort, but it is important to understand the full impact of any choice, over the full life-cycle of a thing or activity. We should not let a lack of perfect solutions stop us taking action [8].

How to engage with the Concerned or Cautious?

There are many different styles of engagement. This is my personal perspective, but everyone can develop their own style.

There can be a tendency to try to argue facts with people, but this can be difficult. If the challenge is based on some bad reading of a topic, and is not something you feel qualified to respond to, is that the end of the conversation? I would argue that with a questioning approach, a fruitful conversation is still possible.

Questionable challenges come in a variety of categories. Here are a few key ones: 

  • Simply fallacies of argument that require no knowledge of the facts per se.
  • ‘What about?’ type challenges that are aimed at deflecting from a core issue.
  • Misunderstandings in the nature of a system, that often ignore important aspects of the system.

These can cover quite a wide range of what one might hear at a climate stall or over a coffee with friends. Often they are combined in different ways, but usually one of these plays a central role.

Simple fallacies of argument

There are many resources that deal with critical thinking and fallacies of argument. The Greeks were familiar with many of them, and they are still used in debates. Debates and conversations on climate change are not immune to fallacies of argument.

Here is one example:

‘By far the greatest use of peat in the world is burning it for fuel, so isn’t stopping its use in our gardens really just virtue signalling?’

In such cases, you don’t need to google the actual numbers because this is a simple logical fallacy and the best way to deal with it is to substitute another example that exposes its flaws:

‘If it was true that the greatest number of wife abusers in the world is in <another country>, would it be ok to say that calling for a stop to wife beating in the UK is really just virtue signalling?’

That is obviously nonsense, but then so is the argument against stopping using peat in gardening.

There are are countless examples of the use of fallacies of argument. One advocate from a think tank that denied the need for action on climate change made a statement on TV along these lines:

‘I am not a climate denier, but this latest scientific report is saying we must reach net zero by 2050, which seems to be ludicrously exact in its timing, doesn’t it?’

This is what might be termed the Fallacy of Precision. My response would be through a progressive sequence of questions:

‘You do accept that warming will increase with more emissions?’ (if not, that reveals climate science denial)

‘You do accept that more warming will cause more extreme weather events and therefore more impacts?’ (if not, that reveals climate science denial)

‘So you accept that the sooner we make cuts the greater our ability to reduce harms?’ (if not, that reveals they don’t understand that prevention is always better than cure)

So in response to this example of the Fallacy of Precision, the key argument is:

‘It is ok to get there early; I’m happy with 2050 +/- 5 years! It is not about binaries. The longer we delay, the greater the risks. 2050 is a political planning goal, and to declare it is not saying there are no risks before that date, and catastrophe after it. The impacts are already being felt, and will increase with more emissions.’

What about?

Whataboutery is as old as the hills.

A very common one I encounter is:

‘What about China? The UK has a tiny footprint by comparison’

My personal favourite immediate response is the take the iPhone out of my pocket and ask:

‘Where do you think this was manufactured?’ (they normally guess right, yes, China)

then follow up with

‘So how do we account for the associated carbon?’ 

They realise that they have to concede that it isn’t quite so simple as blaming China, but the comeback is often:

‘Yes, but population growth is a big issue isn’t it?’

I respond that I acknowledge the issue of resource depletion, but in the context of climate change, I am concerned with the idea that we should place the blame for our situation on the poorest in the world. Africa has been responsible for just 3% of emissions, yet will be hit very badly by climate change; worse than us. At this point I often get out a pen and paper and ask if they are familiar with the Oxfam Extreme Carbon Inequality report? Most are not, so I sketch out the key figure based on the report [9]

Hand sketch by Richard Erskine, based on Oxfam ‘Extreme Carbon Inequality’ report.

‘This shows that the richest 10% of the world’s population have been responsible for 50% of carbon emissions, yet the poorest 50% have only been responsible for 10% of emissions.’

This is a great conversation starter, because it can lead in many directions:

  • historic emissions;
  • funding for adaptation;
  • per capita versus national emissions;
  • resource depletion;
  • educating girls;
  • low carbon development for poorer countries;
  • climate justice; 
  • and much more.

This is an area that is not awash with easy solutions, but it is a chance to challenge simplistic claims that population growth is the cause of the climate crisis, when in fact, consumption growth (propelled by fossil fuelled energy) is demonstrably the primary cause.

Misunderstandings in the nature of a system

Here is one example of a claim I heard recently:

‘Blue Whales eat krill and poo 3 tonnes  a day, so if we got them back to the levels in the oceans before humans decimated their numbers, we could draw down most of the carbon we emit. Problem solved’

The person involved was a huge fan of what are called ‘natural solutions’, and that is fine, as long it isn’t used to dismiss other valid solutions (which was his intention, based on other remarks he made dismissing Wind Turbines etc.).

This illustrates the immediate difficulty for someone at a climate stall in a market who is no expert on carbon cycles, whales or even the total carbon emissions emitted by humanity. But interestingly, despite those apparent shortcomings, it is possible to challenge such a claim …

… by using questions back at the questioner, using the ‘little knowledge’ I shared earlier.

It is crucial that the response is not merely a counter statement. Always start with questions. Ones like:

‘I’d be interested to read more on this idea, do you have a good source?’ (if it is simply a second hand belief that has not been properly researched, they may stumble a bit here)

‘How long would it take to build up the Blue Whale population, and would it be in time to avert dangerous global warming?’ (this may elicit a response like ‘maybe 50 years’, and the follow up might be ‘do we have 50 years?’)

‘That’s interesting, but can you explain why the atmosphere has been so stable since the last ice age, even before we started decimating the whale population?’ (this is of course a trick question, but a valid one. The whales’ contribution to carbon cycles was there 5,000 years ago, yet the carbon dioxide levels didn’t drop because of it; it was in balance)

This could lead to a co-discovery of some more information. Maybe a bit more reading on carbon cycles and so on. Maybe the conclusion will be that we need the whales back, but they won’t get us out of our current predicament.


These are just examples of actual encounters, but I hope they give a flavour of the approach I like to take.

Those new to climate change who want to engage friends, neighbours and others should not feel intimidated. Responding to someone who expresses certainty with questions is always a reasonable approach, that everyone can learn from. If you are part of a fledgling community climate group, you can develop your confidence by working with others when running a climate stall. Learn from others who are more experienced, and then start to have a go yourself. Practice makes better (don’t be beguiled by the illusion of perfect!).

Remember, the great majority of people out there are on your side, and even those that are not, manage to be polite when face to face, in person.

And try to reduce your time on Twitter. Yes, that’s you I’m talking to Richard!

© Richard W. Erskine, 2022


  1. Katharine Hayhoe, Saving Us – A Climate Scientist’s Case for Hope and Healing in a Divided World, Simon & Schuster, 2021.
  1. BEIS Public Attitudes Tracker: Net Zero and Climate Change Winter 2021, 
  1. Yale Climate Change Communications ‘6 Americas’,
  1. Since the end of the last ice age, the levels of atmospheric carbon dioxide was stable at just under 300 parts per million (ppm), but since the industrial revolution it has risen to over 400 ppm; higher than at any time in the last 3 million years. The nearly 10,000 years since the end of the last ice age have been relatively stable, and civilisation and agriculture have blossomed in this period.
  1. Carbon cycles are just that. There are short-term cycles (like the Northern Hemisphere’s autumn and spring cycle, leading to flows of carbon into and out of the atmosphere) but also longer term ones. The longest are geological in timescale. The oceans store huge amounts of carbon in their depths, but there are chemical, physical and biological processes that mean carbon flows into and out of the atmosphere. The reason for the stability of the pre-industrial concentration in the atmosphere is precisely because a combination of these cycles has created a balance. The balance can be disrupted and changed over long periods. The current disruption is extremely fast and man-made.
  1. Carbon dioxide is called a ‘long-lived greenhouse gas’. When humans emit an amount of it into the atmosphere about half is absorbed in the oceans and biosphere, about half remains in the atmosphere, and because the the balancing cycles (and despite the fact that individual molecules may move back and forth on quite short timescales), the raised concentration in the atmosphere remains raised for a very long time.
  1. I’ve answered the question ‘Is 2°C a Big Deal?’ in another essay: According the the Intergovernmental Panel on Climate Change (IPCC), a rise in global mean surface temperatures is already having impacts and every additional 0.1°C of rise has consequences, so it is now urgent to try to avoid 1.5°C and at least 2°C. They found that the difference between 1.5°C and 2°C was huge, in terms of impacts; and the risks escalate if we go above 2°C. All policies and actions need to be judged on whether they fit into the narrowing window of time.
  1. All societal and personal choices have a carbon impact of some sort, but it is important to understand the full impact of any choice, over the full life-cycle of a thing or activity. One considers how bad one thing is, it has to be considered alongside the alternatives. We all have to live, to breath, travel to work or play, etc. and so we have to consider a ‘balance of harms’ and also, a ‘balance of benefits’.
  1. Extreme Carbon Inequality, Oxfam, 2015 

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How hard will it be to scale up heat pump capacity in the UK?

I want to challenge the assumption that scaling up heat pump capacity in the UK is very hard. 

In many ways this belief is symptomatic of a wider malaise in the approach to skills we have had in the UK for far too long. Maybe the crisis in energy – and particularly gas – now confronting us is the jolt we needed to do a rethink.

Scaling is only hard if we still frame the challenge in the same ways we do today – in terms of number of certificates gained through further education colleges. This is not the answer. 

We need something far more like the apprenticeships of old – not those where all the money pours into the colleges, but one where the firms who are doing the real competency development through practice get a decent share of the funding.

Another implicit assumption that needs challenging, is that we need to create clones of experts with very deep heat pump expertise. I don’t think that is true (except maybe in very hard or non-standard outlier cases). In all technologies, as they mature, there is an element of de-skilling that takes place. 

An example is software, where modern tools alleviate a lot of the skills hitherto required in, for example, creating a web site. Although this can reframe the skills question, and quite different design skills can emerge (e.g. illustrators rather than coders).

Heat pumps have matured to the point where we are near to this point (but they still have some work to do to simplify their manuals further).

Finally, we need to scale up the number of heat pump SMEs (Small and Medium sized Enterprises). A massive strategic blunder would be to see the challenge as retraining 100,000 existing one-man-band boiler fitters/ plumbers, to turn them into 100,000 one-man-band heat pump fitters/ plumbers.

A new SME-led approach would put the emphasis on competency development and rebalancing the training budget, with more of the funding going towards the SMEs who can grow the right skills, and do this organically.

We may still need training colleges, but we have to accept that the current model is broken and it is not fit for purpose, and certainly not for our current emergency; their role needs to be radically transformed.

If a heat pump project is broken down into its distinct roles and competencies, the challenge becomes much easier. 

In what follows, I am assuming an air-source heat pump (ASHP) and a ‘wet’ heat distribution system (pipes and wall-mounted radiators), as this will apply for the overwhelming majority of homes that need to transition from gas boilers (to be ‘retrofitted’).

Meet the total UK team that would be needed to install 1,000,000 heat pumps a year by 2030 [1]:

  • 9,000 electricians with expertise in configuring heat pumps.
  • 4,500 assessors/ designers to assess a property, carry out heat loss calculations, and size and design the whole system (heat pump, hot water tank and radiators). This is the most critical role to ensure the overall system design performs to the efficiency expected.
  • 45,000 plumbers required to follow the designs given to them, but not to understand heat pumps in any depth.

Britain with the help of its allies trained 100,000+ pilots in WW2 in just a few  years, and many more women and men building the planes. They didn’t do that by sitting them in classrooms, trying to get them to understand aerodynamics! They got plonked into two seaters and were soon taking the controls.

We need to be honest about the malfunctioning monetised approach to technical training in the UK (actually, most ‘higher education’), and instead focus on practical skills, competency development, and real world practice / achievements. I recommend a great discussion on the issue of ‘resources not courses’ [2]. 

I asked a plumber who was part of the team that installed the heat pump in my house about his college training. He told me “I didn’t get much out of it. I only really learned what I was doing when I left college and started work, and it took a few years to gain my confidence”.

The individual tasks involved in assessing, designing, installing and commissioning a ‘heat pump system’ can be broken down and assigned to roles with the right skills.  I have outlined the project in the notes [3].

The interesting observation is that the plumber is the role which puts in the most hours on the project (to do traditional things like bending copper pipes), but requires the least level of knowledge on heat pumps. They just need to follow the design handed to them. So scaling capacity, if targeted effectively, can be very effective. I have included a skills table in the notes.

The assessor/ designer who was on the team that installed the heat pump in my house – let’s call her Chloe – was a physics graduate in her late 20s. She made easy work of the assessment, calculations and design, and putting together the proposal for the overall solution.

In 10 years, would it really be so hard to scale an SME-led model, including cross-trained electricians and plumbers, and developing a new career path for ‘heat pump assessor/ designers’ like Chloe?

Let’s not talk ourselves into defeat.

We just need to get smart, and organised, and fund the right things.

© Richard W. Erskine, 2022


[1] Estimate of roles required for a typical dwelling

Average man-days
per house
Workforce required for 1,000,000 installation per year,
assuming 230 working days a year
Assessor/ designer14,348
Electrician/ configurer28,696

Note that 10 man-days per house, would typically mean 2 plumbers for 5 days.

[2] Resources not courses

There are deep issues with teaching and training in the UK. The marketisation of education and training means that further education colleges are paid for accrediting students, not developing true competencies. There is a great discussion on this in relation to heat pumps at the BetaTalk – The Renewable Energy and Low Carbon Heating Podcast in the episode The Training Fiasco in Plumbing & Heating – I am certainly not claiming there is an easy way of fixing the training issues in the UK. I am simply saying we can reframe the problem through better organisations and coordination of the roles and skills.

[3] Project outline

  1. Assessment of the heat loss of the house in its given state of fabric, in order to ensure that the heat pump can deliver the peak load required, during the depths of winter. This must be done room by room to ensure correctly sized radiators in every room. Other aspects to be assessed are the existing pipework, radiators, power supply and water pressure.
  1. Design of the whole system, including the air-source heat pump (ASHP), and requirements for hot water, and radiator heat distribution. Any upgrades of radiators will be part of the design, as well as decisions on the peak flow temperature required.
  1. Installation includes several tasks. Physical installation of the ASHP and associated kit (control system, buffer tanks, etc.). Connection to the electricity supply. Connecting the heat pump sub-system to the existing pipework, and upgrading any radiators as per the design. Then ‘balancing radiators’ to ensure optimal heat distribution.
  1. Commissioning involves configuration of the controls (including ‘weather compensation’) to maximise the efficiency of the heat pump during all weathers, and enabling effective energy monitoring so that the customer can see how well the system performs over days, months and years; and finally, ensuring all the paperwork is completed with certification authorities such as MCS (Microgeneration Certification Scheme).

Each hands-on role can be addressed differently in terms of scaling capacity. We will need:

  • An assessor/ designer, who can also play the role of designer, and needs a high level of knowledge of the overall system aspects.
  • A plumber who will do pipework and deal with physical kit installation, but requires only limited knowledge of heat pumps.
  • An electrician/ configurer with high skills in the specific heat pumps installed, and their controls.

Other roles not directly involved are management, accounts, supply chain/ store manager, sales & marketing, and these are important as in any similar business, but don’t ‘scale’ anywhere near as fast as the hands-on roles.

Here is how the the hands-on roles match the stages in the project:

Assessor/ DesignerPlumberElectrician/ Configurer




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Fracking noises off

In the face of turmoil in the gas markets, it’s not surprising that multiple articles and opinion pieces have been pouring forth on fracking for gas in the UK – and calling for a delay to the transition to low carbon – from the same nexus of right-wingers (GWPF, etc.) who have spent years denying global warming, and deny the impacts are anything to worry about (despite the latest stark warnings from the IPCC summarised by Carbon Brief)

Not happy with denying the causes and impacts, of man-made global warming, the next stop for these bad-faith actors has been to deny the solutions. Hence the stream of nonsense attacks on EVs and Heat Pumps recycled year after year, and month after month, with increasingly shrill voices as the adoption of these solutions begins to demonstrate traction. 

Market forces guys, you should love that!

No, they will never let the science – which shows the overwhelming logic of electrification of end-use technologies – get in the way of their ideologically based opinions.

It is of course a long-running multifaceted campaign by right-wing ‘think tanks’, such as GWPF in UK and Heartland Institute in the USA, that have hitherto been successful in slowing action on climate change. Now the tide has turned in recent years, and they know that public opinion is not on their side, but that won’t stop them finding opportunities to muddy the waters.

And we are in the midst of just such an opportunity, and you can imagine them thinking:

I know! Let’s exploit the Ukrainian tragedy and crisis in gas markets – and anxieties in UK society – to double down on anti-renewables, and demand more pro-fossil fuel exploration; especially fracking. 

So their latest stunt is to coordinate articles in the Telegraph etc. and a letter from the usual suspects in parliament; some affiliated or cosying up to those very same denialist right wing ‘think tanks’.  

For those of us that are genuinely concerned about UK energy security and resilience, and a greener future that will make us more resilient in every way – food security, conserving nature, and much more – the question is: what to do?

Keep calm and carry on is my main message.

The path to net zero will continue to be bumpy. Getting off our addiction to  fossil fuels has withdrawal symptoms. A serious fight back and disinformation war from vested interests was inevitable. They see action on climate change as a threat to their illusory vision of an unfettered ‘free market’; so regulations to address harms to the environment, nature and human health are an anathema to them. Hence Trump’s attempts to eviscerate the U.S. Environmental Protection Agency.

The good news is that only a dwindling segment of the population are ‘dismissives’ (to use the nomenclature of the Six Americas), making up just 9% of US population. 

Similarly in UK, there is a majority who want action on climate change.  The latest UK Public Attitudes Tracker (BEIS, Autumn 2021), shows that 85% of the UK adults were concerned about climate change, and 87% supported renewables. Whereas only 17% supported fracking.

It’s not just the public who are sceptical about fracking, energy experts question the potential role that fracking could play in the medium term to address soaring energy prices

You can understand why the likes of Steve Baker MP, Matt Ridley, et al are becoming increasingly desperate and alarmist. Expect more heat, and even less light, from the Net Zero Scrutiny Group, GWPF, etc., and their various enablers in the media.

Give the noises off a rest guys, it ain’t working.

© Richard W. Erskine, 2022


In-depth Q&A: The IPCC’s sixth assessment on how climate change impacts the world, Carbon Brief, 28th February 2022,

Why fracking is not the answer to soaring UK gas prices, Professor Michael Bradshaw and co-authors, The Conversation, 2nd March 2022 

BEIS Public Attitudes Tracker: Autumn 2021 

Global Warming’s Six Americas, Yale Program on Climate Communications, September 2021 

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Is Putin mad?

It seems bizarre that the fate of the world might hinge on this question, on the psychological state of one man, but this is where we are.

We are told that a NATO secured ‘no fly’ zone over Ukraine is not possible, because it might trigger World War III, and ultimately Mutually Assured Destruction (MAD) with an exchange of strategic nuclear weapons.

We know that nuclear weapons do not prevent terrorism, civil wars or conventional ones, and ‘great power’ proxy wars have been a scourge on the world since 1945.

Near misses between nuclear powers have been far more frequent than many realise. As Sasan Aglani states:

“A recent Chatham House report documents 13 instances between 1962 and 2002 where nuclear weapons were almost inadvertently used due to miscalculation, miscommunication, or technical errors. What prevented their use on many of these occasions was the ‘human judgement factor’ – intervention of individuals who, based on prudent assessment of situations and against protocol, either refused to authorise a nuclear strike or relay information that would likely have led to the use of nuclear weapons.”

And in the latest moment of high risk, NATO’s nuclear weapons haven’t restrained Putin; far from it.

In a sense, they have enabled him.

Nuclear deterrence is usually described in the simplistic terms parroted by politicians, and as the UK’s Ministry of Defence describes:

“Potential aggressors know that the costs of attacking the UK, or our NATO allies, could far outweigh any benefit the could hope to achieve”.

But this was the obsolete MAD strategy of the 1950s, not the more complex picture that emerged from the 1960s onwards: flexible response.

Both US and Russian military strategists were unhappy with a nuclear force that was literally incredible. They needed some way to make MAD credible, that is, to make nuclear weapons usable.

The answer was a ladder of response: the threat of battlefield nuclear weapons would cause an opposing large conventional force to think again. If that failed to deter, then medium range nuclear weapons would do the trick. The ultimate ‘deterrent’ would be strategic intercontinental multiple warhead missiles.

But this is the kind of theoretical scheme dreamt up by wonks in think tanks. It can be tested in war games but not in practice, and certainly not with Putin in the room, playing the game. 

It takes no account of accidents, miscalculation or, dare I say, one mad man who refuses to act logically.

If Putin ordered a battlefield nuclear weapon attack on a Ukrainian city that refused to submit, what would NATO do then? 

Would Putin go this far, risking that “it might trigger World War III”?

He seems to like taking risks, crossing red lines and getting away with it.

Each time, the world tutted, and looked away, even though the plan was already pretty clear. His intentions towards Ukraine have hardly been a secret. He has given many speeches on the state of the west (which have enamered him to the religious far right in the west), and the need to rebuild a greater Russia.

He clearly wants to undermine western democracies and any countries in Russia’s orbit aspiring to join them.

Putin has always been testing, probing, and seeing what lines can be crossed. 

Is Putin mad?

The problem for the west is that he only needs to appear to be mad to get away with it, and so far he’s doing a pretty good job at that.

We must hope against hope for China to restrain him, for a palace revolt, or anything to restrain his worst impulses.

And when we are through this, in however many years it takes, we must finally stop this irrational belief that nuclear weapons make us secure, and make us safer.

Post-Putin, the world will have been warned again of its folly in trusting in these genocidal weapons.

We must all work towards their total eradication.

Richard W. Erskine, 2nd March 2022.

A little background …

During the 1980s I was research co-ordinator for SANA (Scientists Against Nuclear Arms) and on their National Coordinating Committee. It became SGR (Scientists for Global Responsibility) and remains very active, with many great reports and research on nuclear weapons, non-military research careers, climate change, and much more. SGR’s work on nuclear weapons contributed to the International Campaign to Abolish Nuclear Weapons (ICAN), who went on to win the 2017 Nobel Peace Prize.

Please visit SGR’s website and donate towards their important work. 

This essay is a personal piece with a personal viewpoint, as I am just an ordinary member of SGR these days, but I continue to support their great work.

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Musings from the loft clearance: nuclear weapons, climate change, and denial

Clearing out over 40 years of files can throw up so many surprises and emotions. This box contained files from the 1980s when I was in my spare time research coordinator for SANA (Scientists Against Nuclear Arms).

One file, preparatory work we did for a local authority preparing a report on the likely impacts of a nuclear attack (countering the whitewashing ‘Protect and Survive’ from the UK’s Home Office). I wrote a program that ran on an Amstrad 8256 to do the maths on casualties.

We helped several local authorities to speak truth to the powers that were telling people to whitewash their windows! The group became a kind of research group for the peace movement, often working quietly from bedrooms and offices, trying to make a difference.

Meanwhile those in the front line – those brilliant Greenham Women – faced the reaction of those who turned fear into hate, stirred by the same media outlets who today pour scorn on those demanding action.

Where is the statue to those brave ladies I muse, as I flick through another file full of newspaper cuttings?

Another file on readings of psychological responses to the nuclear threat, which I summarised on a one pager. Some of the insights seem universal. Denial is a complex condition, and I always cringe when those in denial on climate change feel they are being linked to holocaust denial.

The truth is that most of us are in denial much of the time, because we’d go crazy otherwise. But there are consequences to this.

In my life I stepped back from active work on the nuclear issue to focus on family and career. Burnt out you might say, and needing a break.

Only in my retirement did I wake up to climate change, after reading Naomi Klein’s ‘This Changes Everything’, and then hearing her speak in Cheltenham. That was quite the kick up the proverbial!

The nuclear threat has not gone away and Russia is now escalating the risks. C.E. Osgood said

“the policy of mutual deterrence includes no provision for its own resolution”.

The risks are pretty binary.

Climate change is different despite some who suggest otherwise (its scales of damage, creeping past us and towards us), but the psychology has common threads.

People ask why decent cultured Germans did not stop the Nazis. Their denial was much more relevant to our current situation than the denial of neo-nazis regarding the holocaust, or the denial of dangerous man-made global warming by the self-appointed ‘contrarians’ who control the right wing media.

It is not that people are intellectually ‘in denial’, any more than a smoker who knows very well the health risks. It is the emotionally centred denial that puts off action.

People are worried about climate change and want action taken – overwhelmingly they do, as studies clearly show – but they have been unable to get beyond that numbing inability to turn wishes into actions. It all seems too much.

As Sandman and Valenti said in relation to the nuclear threat: People are neither apathetic nor actively terrified, but they are psychologically numbed.

The “don’t make a fuss” narrative is alive and well, and soon to be brought into law by our Home Secretary Priti Patel.

But those who did and do make a fuss – The suffragettes, Greenham Women and XR – had the same energy, the same moral outrage which we too often keep bottled up. It hasn’t escaped my notice that it is often women who are the first to step forward, to speak up.

Being polite and “reasonable” can do a lot but rarely is enough to shift powerful forces using propaganda to manipulate public sentiment (to aid in the process of mass denial).

The great psychologist Dorothy Rowe said, in relation to Bomb that we need to convert anger & depression into hope and action. Protest is never enough.

E.L. Long wrote in 1950 in relation to nuclear threat

“scientists had overestimated … power of their message to reform a culture that has ignored other seers and prophets for many ages”.

Only positive visions and futures can change the psychology of mass denial on climate change. Nuclear threats are oddly more intractable, but ought to be simpler, to resolve.

On climate change I veer between despair and optimism, but as many wise heads have said, hope is important, but much easier to sustain if coupled with action: engaging with the community, local counsellors, national politicians, businesses and the rest.

As Katharine Hayhoe replies when asked “what is the first thing I should do about climate change?”

“talk about it!”

with family, friends, colleagues.

Those forces who want to delay action, are happy to have a psychologically numbed populace. Talk and engagement is a great antedote. Telling your counsellors and parliamentary candidates that your vote depends on them demonstrating they really mean action, is another. We all have agency in some or many forms.

Now, I must get back to clearing more of those boxes and piles of papers, no doubt uncovering more memories, triggering more musings.

(c) Richard W. Erskine, 2022


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The Catch-22 of COVID-19

Many MPs have tonight voted against measures to protect public health. 

A majority of these did so in the name of freedom, in denial that the fast spreading Omicron variant of Covid-19 is any worse than seasonal flu. Freedom trumps all, according to these ‘contrarians’. The market is king, and the market solves all problems, so the main job of Government is to enable business to do its thing.

As is well documented, ‘doubt is our product’ is the motto that tobacco executives secretly adopted in the face of the unequivocal risk from smoking revealed by scientists, and is now the reflex modus operandi of the anti-science contrarians working assiduously to undermine experts.

It is always the same people. Whether it be smoking causing lung cancer, CFCs causing a hole in the ozone layer, action on climate change, or health measures during a pandemic, those anti-science contrarians will be voting against any regulations to protect people. 

Of course the Catch-22 for those working on actions to avoid the worst, is that for the contrarians, they will use any such success as evidence that the worst projections were an exaggeration in the first place!

You fixed the roof – so all those dire warnings of an impending leak in the roof if it wasn’t retiled were just scare-mongering.

You banned CFCs, and the ozone layer is repairing – as we said there would be no dangerous levels of UV radiation.

You fix some dodgy code (the Millennium or Y2K bug) so the programs would still work after the year 2000 – You see, it was not a problem after all.

You enacted measures to reduce human contact during a pandemic – We told you, the NHS would not be brought to its knees.

You set out actions needed to avoid dangerous man-made climate change – You doomers, the dangers are exaggerated and we should wait to see who is right.

To prove the point, the public officials and experts would have to not act, to let things rip, so that disaster then strikes, and they can then say ‘told you so!’ – but of course they do act.

But the contrarians rarely totally prevent action being taken – even with the worst Governments – but they can effectively delay it.  They are good at that.

Many deaths that could have been avoided result from these delays. There is no freedom for them or their bereaved families.

(c) Richard W. Erskine, 14th December 2021

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Insulate Britain! Yes, but by how much?

Upated 14th April 2022 including ‘Summary’ and new section ‘Cost-effectiveness of fabric/ renovation measures to deal with peak heat demand’

If you like this essay, you may also be interested in Heating a listed Cotswold stone building with an air-source heat pump: our journey


  • Consider all retrofit options
    • insulation [both simple (loft) and deeper (e.g. external wall)], draught-proofing, moisture management, and last but not least, a heat pump.
    • a householder will in most cases need to make choices: don’t let the perfect be the enemy of the good
    • two identical homes may come to different decisions – there is no single ‘right’ answer
    • ignore anyone who says “you need deep retrofit before considering a heat pump” (the essay includes fully referenced debunking of this assertion, but it is widely believed and repeated ad nauseum)
  • Be clear about your priorities (comfort, costs, climate)
    • comfort is important, but it is subjective. MCS (Microgeneration Certification Scheme) has standards for target temperature in homes (21°C in living spaces, 18°C for halls and bedrooms). The term ‘comfort’ does not necessarily justify exceeding this standard.
    • capital costs and running costs both need to be considered – fluid and escalating gas prices are a major issue, whereas electricity can come from many sources (wind, solar, nuclear, tidal, etc.), so is future proofed.
    • if climate is your priority, be aware that timing is key, and the UK and other countries need to decarbonise heating, transport, etc. by 2050
    • in terms of domestic heating, getting off gas is the single best thing you can do, and because heat pumps are so efficient, heat pumps deliver the greatest carbon savings per capital investment by a very large margin of all retrofit measures, without necessarily an increase in running costs!
  • Maybe don’t rip out a NEW kitchen or NEW gas boiler
    • so if you spent £20,000 on a new kitchen 5 years ago, and are now told that the back wall needs insulating, and can’t be done externally for various reasons, maybe this option is not in play.
    • if you have a new gas boiler, check it is operating at optimal efficiency (that it is condensing and is running at lowest possible flow temperature to meet heat demand), thus reducing bills while maintaining comfort; and maybe deferring decision to switch to a heat pump. The Heating Hub offer ideas and support on optimising existing gas boilers, along with many other topics.
  • Decide on budgets/timescales
    • even with grants, household expenditure may be highly constrained
    • consider the disruption as well as costs of different measures, and a realistic plan
    • fabric measures can take several (or many) years to complete (when living with the work).
    • decide on maximum budget and timescale for all measures
  • Do as much fabric as budget allows
    • be aware that deep (fabric) retrofit could exceed cost of heat pump by factor of 3 ot 4
    • prioritise the “must do” ‘bangs for bucks’ measures such as draught proofing and loft insulation that are relatively cheap and with very high payback
    • going deeper is where the householder must make a balanced (dare I say “pragmatic”) decision.
  • Leave some money in budget for an air-source heat pump (ASHP), if you want one
    • ignore myths like “heat pumps can’t heat old buildings” or “they don’t work when its cold” (see here)
    • since an ASHP is much more affordable than alternatives (ground or water), it will be the default heat pump option (for those that are not in flats that may alternatively be connected to a district heating system, which itself can be ‘powered’ using a commercial-scale water-source heat pump).
    • if you are not planning ‘deep retrofit’ there are limited risks from modest ‘oversizing’ of an ASHP if installed before all insulation measures are complete (as a modern ASHP can already handle seasonal variations in demand); but discuss with expert installer.
    • you can get an ASHP early in your retrofit journey, if climate is your priority (and increasingly, running costs also); with no regrets!

Longer read:

If you are confused about what to do about retrofit, you are probably not alone. There is so much mixed and conflicting messaging. Often statements are made in the media that are untrue and go unchallenged.

Some experts say we need to insulate our homes so well they will hardly need any heating! Others say we need to get off gas as fast as possible by installing heat pumps.

Who is right?

Part of the confusion is that commentators can have different objectives in mind when expressing their opinions:

  • To reduce household bills;
  • To improve comfort;
  • To reduce reliance on gas;
  • To lower risks to future bills, from volatile gas markets;
  • To reduce the carbon footprint of heating.

Or some combination of these. But these assumptions are often not made clear, and homeowners can be led down different paths depending on who they talk to.

Now, in the face of the climate emergency, everyone is saying that the last of these is something they care deeply about, but the pathway to getting to net zero in heating is something that is hotly debated.

We don’t have much time to get this right, and as Voltaire once noted, the best should not be the enemy of the good. We need a pragmatic way forward.

Energy Performance Certificates

Householders will often be further confused when they look at the Energy Performance Certificate (EPC) of their home or one they want to buy. EPCs are increasingly seen as unfit for purpose in the effort to decarbonise heating. The Country Land and Business Association (CLA) stated (as quoted in an Historic England report from 2018).:

“The EPC confounds cost-effectiveness, energy efficiency and environmental performance, giving an inadequate estimate of all three. … it must focus solely on one of .. [to] be an effective baseline for policy interventions”

An EPC in its current form has never recommended a heat pump as a primary measure, because of in-built biases against heat pumps. If we really want to encourage ‘whole house’ retrofit that includes a sufficiency of insulation work and displacing gas (or oil or LPG) boilers with heat pumps, we will need instruments that are fit for purpose (see Updates A.)

So what to do?

Householders will naturally ask: How much will it cost? How fast can it be done? Who can I get to advise me? What is the carbon reduction? Who can do the work to a good standard?

Is ‘deep retrofit’ required?

The Committee on Climate Change (CCC) in their 6th Carbon Budget stated (based on very detailed modelling of scenarios, costs and risks):

‘By 2030 37% of public and commercial heat demand is met by low-carbon sources. Of this low-carbon heat demand 65% is met by heat pumps, 32% district heating and 3% biomass. By 2050 all heat demand is met by low-carbon sources of which 52% is heat pumps, 42% is district heat, 5% is hydrogen boilers and around 1% is new direct electric heating.’

for their ‘balanced pathway’, and they did not assume deep levels of retrofit (p.113):

‘Energy efficiency and behavioural measures in our Balanced Pathway deliver a 12% reduction in heat demand to 2050’,

which implies quite modest fabric retrofit. This, on average, requires an estimated budget (see p. 297) of just £10,000 per household. This is far below what is the estimated ‘deep retrofit’ budget of nearly £40,000 [1].

The CCC are clearly working on the basis of pragmatic or sufficient levels of insulation and other fabric measures, not ‘deep’ retrofit.

The Retrofit Academy is devoted to training to improve the quality of assessments and implementation of ‘fabric’ measures (insulation, air quality, etc.), which is to be applauded. It is however concerning that they essentially marginalise heat pumps [2]:

“Deep extensive retrofit and fabric first approach needs to be the main focus of reducing carbon emissions before we will be able to move to low carbon heating technologies 100%”.

There is clearly a problem here, as this is not an isolated opinion.

The ‘retrofit community’ generally have established an article of faith that ‘deep retrofit’ is essential. This is a belief that has very deep roots and predates concerns about the climate emergency. Key organisations in the public and private sector promote this belief.

Their motivation is to create greater comfort in homes and to lower heating bills, and who can argue with this?

The problem is that it isn’t a realistic strategy for reaching net zero in the fastest time possible [3].

The benefits in financial terms for householders do not favour a deep retrofit approach [4], but suggests that buyers do value heat pumps [5].

The Retrofit Academy justify their position on heat pumps based on the belief that that the grid cannot cope.

This is the same kind of argument that is often used for why we can’t adopt Electric Vehicles (EVs): because there aren’t enough charging points. On that basis we’d never have replaced horse-drawn carriages with petrol cars, or indeed any technology that displaces an old technology. In all such cases, the infrastructure is developed in parallel with the adoption of the technology in use. You don’t wait till you have a fully developed charging network and beefed-up electricity grid (particularly at its periphery) before you start selling EVs.

The electrification of much of our energy use is an inevitable strategic transformation of the energy system for many reasons, not least of which is the end-use efficiency improvements that technologies like EVs and heat pumps deliver. The other strategic game changer is that the end-use of energy does not care where the electricity comes from: a wind farm in the North Sea; the solar PV on a householder’s roof; a community solar scheme; a nuclear power station; or even, fusion energy (if it ever becomes a commercial reality). Electrification completely future proofs our energy system (even those parts of the economy like Aviation that need ‘chemistry’ to decarbonise, can get synthetic fuels from renewable electricity).

As for the grid, the issue has been overstated. There will be some strengthening of the grid required but a whole host of measures mitigate peaks in demand, including energy storage (at multiple scales), demand shifting, smart metering, etc. These will ensure that the grid can readily cope with future demand. No one is expecting that we have a 100% switch to heat pumps overnight, any more than petrol cars replaced horse-drawn carriages overnight. It is a multi-track transformation of energy generation, distribution and use. Local generation can have a remearkable impact on the scaling up of renewables as discussed here.

A Net Zero Toolkit for Retrofit

Retrofit assessors need to take an holistic and pragmatic view of the problem of decarbonising heating.

The ‘Net Zero Toolkit’ [1] is an encouraging document because it takes an approach which is very much along these lines. This document reiterates what PAS2035 is trying to achieve:

PAS 2035 follows two core principles:

  • A ‘fabric first’ approach to reduce the heat demand of a building as much as possible and to ensure newly airtight homes are well ventilated and avoid issues with damp and humidity.
  • A ‘whole house approach to retrofit’ to ensure retrofit plans for homes consider improvements to the fabric, services and renewable energy generation in a coherent way to minimise both risks and carbon emissions.

In other words, we need to consider fabric measures and getting off gas (or other fossil fuels) in parallel.

It also takes a ‘risk’ based approach, recommending that assessors consider the possible hurdles not only the benefits of different courses of action.

For a 90m² home (the average floor area for UK houses) the ‘Net Zero Toolkit’ provides costing for a both ‘shallow’ and ‘deep’ retrofit. Including all the potential measures it comes to a total cost of £14,770 for ‘shallow’ and £54,220 for ‘deep’ retrofit. But a heat pump is only included in the ‘deep’ retrofit case, so this is still pursuing the view that deep fabric measures are required before including a heat pump.

Leaving heat pumps till later, after the retrofit budget has potentially been blown on fabric measures, is not the answer. So while the ‘Net Zero Toolkit’ is a great improvement on the apparent Retrofit Academy position, it could go further.

In terms of actual measures recommended, I feel it still falls short of recognising that heat pumps need to be included much earlier in the conversation.

If we include only those measures related to ‘fabric’ (i.e. exclude heating systems and solar energy) the costs are reduced to £10,970 and £38,720, respectively.

How many 90m² floor area home owners have £38,000 to spend, and still have money and appetite left over to do the heat pump project?

‘Fabric first’ can easily become ‘Fabric only’ on this path.

We still have a lack of recognition of the urgency of getting off gas.

What does the Government say?

The Department of Business, Energy and Industrial Strategy (BEIS) in a recent study have findings that completely contradict the position of the Retrofit Academy. BEIS conclude:

‘This project shows that Great Britain’s homes can convert to electric heating at a cost far lower than the accepted wisdom. This can be achieved with no threat to comfort, and greenhouse gas emissions will fall very dramatically as a result.’

In answer to the question on what should be ‘the balance of heating technologies to insulation measures’ they conclude:

‘The work focused on total costs of ownership over 15 years. For most house types and most electric heating systems, the cost-optimal packages of measures have very limited fabric improvements – most commonly just draught-sealing and top-up loft insulation. High-cost improvements, like internal or external wall insulation, hardly ever repay the capital costs over 15 years.’

This is in part why the Government and Climate Change Committee are following a pragmatic approach and see a combination of heat pumps and district heating as cornerstones of heating decarbonisation.

Cost-effectiveness of fabric/ renovation measures to deal with peak heat demand

This essay is focused on decision making at the householder level, not at national system level, but since some concerns has been raised regarding peak (electricity) demand for space heating in winter, I have added this section to look at the cost dimension. There is research published since I first wrote this essay, that analyses the relative cost effectiveness of fabric measures in dealing with peak heat demand at a national level [8]. The paper says:

“Geographically, the amount of saved space heat differs strongly between countries (see figure 8). The strength of building renovation depends on the interplay between the costs of refurbishment and those for energy supply during the heating season.  … Countries with a large share of wind generation, such as Great Britain, Denmark or Portugal, have cheaper electricity in winter and therefore a lower [requirement for] renovation as a result.”

In the UK, and assuming the distribution is allowed to strengthen (why wouldn’t it be, but conservatively with transmission grid is as it is today), then only a 10% reduction in heat demand using renovation/ fabric measures is cost effective. This is a suprising result, but arisies from the UK’s very significant wind assets and future potential, which correlates well with peak heat demand. It is similar to the number projected by the UK’s Climate Change Committee of 12% cited earlier.

I intend to write a separate essay ‘Peak Anxiety’, exploring the national system issue of peak electricity demand. Now I’ll return to the householder perspective.

Why heat pumps must be considered at the start of a retrofit conversation

If we focus on avoiding dangerous global warming, the single biggest thing a householder can do to reduce their carbon foot print is to install a heat pump.

Yes, it must be a fair transition and poorer families need help with grants or other measures to switch away from fossil fuels, but the direction of travel is clear.

I previously illustrated this (see here ), using data from the Energy Saving Trust, plotting the capital cost of different measures versus the carbon saving of those measures per year. I am including this graphic below.

Air-Source Heat Pumps (ASHPs) are now so efficient they compete very favourable with Ground-Source Heat Pumps (GSHPs), and at half the project cost, so we focus on ASHPs, which are likely to dominate the market [6].

An ASHP is the single best way for a householder to reduce their carbon footprint, by a long way.

A retrofit assessor may say,

‘Yes, but we have to consider comfort too. That bay window is poorly insulated so, whether it is a gas boiler or heat pump heating the home, sitting by the window will feel cool and only fabric measures can fix that’.

This is true and a householder needs to express their requirements clearly, and be presented with the options and costs. They can then judge which measures they ‘value’, in terms of the different criteria – comfort, capital costs, running costs and carbon reduction.

Different people with exactly the same situation may arrive at different conclusions.

But if they say that carbon saving is their number one priority, and secondly, they’d like to keep running costs similar, then a heat pump and modest fabric measures is an option that will score extremely well (or should do, if the assessment tools are fit for purpose).

There is another reason why we shouldn’t put all our eggs in the basket of insulation and other fabric measures. Recent research suggests that following such measures, there is a rebound effect and householders make behavioural changes (such as less clothing and higher thermostat settings) that can cancel out the carbon savings (see Update D).

Maybe, instead of the mantra ‘Fabric first’, we need ‘Efficiency first’, because it is that which delivers lower carbon emissions.

How do we deal with hard to treat homes?

The conversation often centres on old leaky homes, of which the UK famously has many. The Buildings Research Eastablishment (BRE) estimated a while ago that the UK had over 10 million ‘hard to treat’ homes (and there are nearly 30 million homes with gas boilers in the UK). About half of these buildings (about 5 million) were built before 1900.

These 10 million are often but not exclusively larger homes with high gas heating bills. So addressing the needs of this 1/3rd of the retrofit challenge would make a disproportionately large contribution to decarbonising heating in the UK.

But whether it is Roger Harrabin reporting on the BBC, or many others who count themselves as ‘green’, we hear it stated repeatedly (without reference to evidence) that householders must have high levels of retrofit before even considering a heat pump.

Some will even repeat the myth that you cannot heat old ‘leaky’ buildings with a heat pump. This is one of the myths that is addressed here.

Heat pump scepticism is wrong for several reasons:

  • you can heat any building with a heat pump that can be heated with a gas boiler (you just need to size the heat pump and the emitters/ radiators correctly);
  • with the efficiency of modern heat pumps and quite modest insulation, a heat pump can match or even reduce the running costs of the boiler it is replacing, as shown here and here;
  • because the electricity grid is getting greener and greener every year, once a heat pump is installed the heating gets greener and greener with every year that follows (as illustrated in the graphic earlier).

But the questions remain: how do we deal with hard to treat homes? How much insulation do we do before we get rid of the old gas boiler?

The heat demand of a building is an important measure of its efficiency, but how do you compare the thermal efficiency of a large 6-bedroom detached house with a 3-bedroom semi? The fair way to do it is to divide the heat demand by the floor area of the house, which gives a measure – the heat demand per unit area – that is a universal measure of the ‘efficiency’ of the building’s fabric.

In the UK, the average home has an annual heat demand, using this measure, of about 130 kilowatthours (thermal energy) per square metre per annum (or 130 kWh/m².a for short). A new build, highly efficient ‘PassivHaus’ requires only 15 kWh/m².a. The Association of Environmentally Conscious Builders (AECB) have a target of 50 kWh/m².a when carrying out a (fabric) retrofit project, but they will relax this (e.g. for a Listed Building) to 100 kWh/m².a in some case, because some measures (like wall insulation) may prove impractical or impossible to include.

The implementation of retrofit on old buildings needs to be done with considerable experience and care, as a report by the Sustainable Traditional Buildings Alliance (STBA), in part sponsored by Historic England, explored.

Let’s start with a 90-100m² home with solid walls that is poorly insulated and ‘hard to treat’, and requires nearly 200 kWh/m².a to heat it currently with its gas boiler.

The following sequence considers a sequence of options (A-E) for when to install an Air-Source Heat Pump (ASHP), alongside increasing levels of ‘fabric’ retrofit measures. As we move from left to right on the bottom axis, fabric measures are added that reduce the heat demand of the building. That in turn will reduce the cost of the heat pump project.

Because we still need hot water and some heating, the drop in the cost of the heat pump project is less dramatic than the rise in the cost of the fabric measures, and there will be a cross-over point where the cumulative cost of the fabric measures is equal to the cost of installing a heat pump (at that level of building efficiency). Let’s run through the options.

A. Doing nothing on fabric or gas means bills will escalate

This is the start – the ‘do nothing’ option.

There is a serious risk that such a home will have lower resale value in the future, and will of course not contribute to lowering the carbon footprint of the home.

By starting to think about retrofit (including getting off gas), home owners might find themselves doing things they have put off for years, like clearing the loft (ready for insulation), and fixing that leaky front door.

B. Getting off gas early prioritises planet, without bills needing to rise

In this case, the householder installs an ASHP early in their retrofit journey, alongside limited fabric measures, such as loft insulation to modern standard, and seals / brushes for doors and sash windows to deal with drafts.

It may be a surprise to people that getting off gas early prioritises planet, without bills needing to rise. The reasons for this are:

  • A 25 year old, 70% efficient gas boiler wastes energy, so the net cost of a unit of ‘heat energy’ delivered is greater than 3p (the nominal unit price for a kWh of gas in July 2021), so 3p/0.7 = 4.3p per kWh of heat delivered/ required.
  • The nominal cost of electricity to run the heat pump (at July 2021 rates) is 15p per kWh. Taking a performance of 300% for a modern properly installed heat pump over the seasons, the householder would be paying 15p/3.0 = 5p per kWh of heat delivered.
  • Assuming that the limited measures taken mean that heat demand reduces by 20% less then we would paying effectively 4p instead, which is lower more than old unit cost (4.3p)
  • As levies on electricity move over to gas in coming years (as the Government has indicated), the running costs of the ASHP will lower further (and will rise for the gas).
  • As the electricity grid gets greener and greener, so does the heat pump, without the householder having to do anything, so the carbon reductions delivered improve year on year.
  • It is crucial that the house has a proper heat loss assessment done, and the heat pump is sized correctly, and that radiators are also assessed and upgraded where necessary on a room by room basis.

This refutes the belief that early adoption of a heat pump is a no-go area for hard to treat homes.

C. Further pragmatic fabric measures lower heat demand and bills

In this case a householder installs an ASHP, and in addition to limited fabric measures – loft insulation to modern standard, and seals / brushes for doors and sash windows to deal with drafts – installs:

  • pragmatic window measures (replacing some windows with double or triple glazing but prioritising lower cost secondary glazing, particularly in conservation area), and;
  • for one or two rooms, additional measures for cold walls or floors where possible, for comfort reasons if nothing else, and;
  • might add localised mechanical ventilation and heat recovery (MVHR) for a specific room or two (kitchen and shower) to deal with condensation issues.

Alongside reducing bills, these fabric measures can deliver improved comfort (such as in key problem areas like bay windows).

D. More fabric measures reduce bills, but can delay getting off gas

The householder installs an ASHP late after extensive and often disruptive retrofit measures to many rooms, including double or triple glazed new windows throughout and insulation for some floors and walls, and extensive MVHR (Mechanical Ventilation and Heat Recovery) recommended to deal with moisture that would otherwise be trapped.

Older buildings are used to ‘breathing’ and that prevents the build up of moisture. As we greatly reduce leaks in these buildings, and add insulation, there are significant risks of harm to the traditional underlying fabric of the building due to moisture. Historic England has documented many cases where harm has been done in old buildings, and they recommend the use of breathable insulation materials to minimise such risks. Moisture can give rise to health issues if mould results.

That is why PAS2035/ PAS2030 aims to deliver improved skills in doing more extensive fabric retrofit. I am concerned that the skills required to effectively assess and implement these more extensive measures, and the costs, will deplete a house owners ‘retrofit budget’ to the extent that there is no money left to switch off gas and install a heat pump.

This is also problematic because a householder will rarely implement fabric measures in a single short-term project. In practice it can take many years to implement a wide range of measures; especially where householders are living with the work.

Often, debates on retrofit fail to take account of these real-world issues of limited budgets, extended timelines, and risks of poor delivery of deeper retrofit. Conversely, the challenges of fitting heat pumps are overstated by comparison. We need a much better balance in these debates.

E. Further fabric measures very difficult to justify

A householder installs an ASHP very late after an extensive and disruptive building project:

  • Removing problematic fabric and replacing with energy efficient materials for walls (internal or external), floors and windows;
  • Possibly going below ground floor level at walls to eliminate thermal bridging issues with floor insulation, and;
  • Full external cladding of building, or internal wall insulation;
  • Installs MVHR throughout the house.

These measures would greatly increase comfort and minimise bills. Heating requirements theoretically become minimal (although hot water would still be required, and specialised heat pumps dedicated to hot water are available).

However, in practice, such levels of fabric retrofit are not achievable for hard-to-treat homes at reasonable levels of cost and disruption. And for Britain’s housing stock, this is not achievable on a timescale commensurate with the climate emergency. This point seems to be lost on advocates for deep retrofit.

People talk about the lack of heat pump engineers, but I would argue that training these up is a relatively simple task when compared with the breadth of knowledge required to deal with a large range of historic and current building materials and how to use them in a way that avoids creating problems.

Pragmatic ‘save the planet’ Retrofit

So these are the householder options:

A) Doing nothing on fabric or gas means bills will escalate;

B) Getting off gas early prioritises planet, without bills needing to rise;

C) Further pragmatic fabric measures lower heat demand and bills;

D) More fabric measures reduce bills, but can delay getting off gas;

E) Further fabric measures very difficult to justify.

And for me, concerned about the urgency to limit dangerous global warming, options B or C are the pragmatic way forward in many cases.

‘Insulate Britain! Yes, but by how much?‘ House owners are asking.

‘By enough’ is the answer, and far less than is the received wisdom of those calling for ‘deep retrofit’.

It certainly needs to be at a level that leaves enough in the budget to get off burning fossil fuels. For many or most householders, that means installing an Air-Source Heat Pump [7].

Anything less is not treating the climate emergency with the urgency it requires.

(c) Richard W. Erskine, 2021 (updates added below, 14th January 2022)


[1] ‘Net Zero Carbon Toolkit’ by Levitt Bernstein, Elementa, Passivhaus Trust and Etude,

This toolkit was commissioned by West Oxfordshire, Cotswold and Forest of Dean District Councils, funded by the LGA Housing Advisers Programme. It is licensed under Creative Commons Licence 4.0 International (CC BY-NC-SA 4.0). Licence Deed:

[2] Guide to Heat Pumps,

[3] Consider a householder who spent £25,000 on a new kitchen 7 years ago and is advised that they need to insulate the back wall of the kitchen and the floor. This would require the kitchen to be removed and expensive and disruptive work must be done to accomplish the work, even assuming the kitchen can be refitted. In practice, many of those who do attempt ‘deep’ retrofit do so only over an extended period rather than as a ‘big bang’ project.

[4] Lucien Cook of Savills was on BBC Radio 4’s ‘Your and Yours’ (8-11-21), quoting from research done by Savills, said that to get from EPC D to C, a householder would need to spend £6,500 but would only reduce energy bills by £180 per year (which would take 36 years to break even).

[5] Lawrence Bowles of Savills, commenting on research on valuations of homes:

‘By analysing average values of homes transacted between 2018 and 2020 we found that homes with newer, cleaner, methods of energy demand a much higher price tag. Across England and Wales, buyers purchasing a home with a heat pump fitted are paying on average 68 per cent more for the offer of cleaner energy.’

[6] As the Renewable Heat Incentive (RHI) ceases at the end of March 2022, with a much higher grant for GSHPs than ASHPs, to be replaced (it has been signalled) by an upfront grant with an expected marginal uplift for GSHPs, the likelihood is that the great majority of heat pump installations will be air source (even for the minority of home homeowners that have the land area for laying the slinkies required; and bore holes are even more costly and risky for a single householder to attempt).

[7] For those who live in flats or dense dwellings in towns and cities an ASHP may be problematic because of lack of space for a cylinder, for example (although small systems are being developed). For such case, and for office buildings, low carbon District Heating will often be the preferred alternative, as the Climate Change Committee recognises. But remember that District Heating refers to a heat distribution network, which still needs a heat source. The heat source may itself be a large scale heat pump, such as the water-source heat pump planned for Stroud District Council. Since towns and cities are typically close to rivers or the sea – carrying huge quantities of thermal energy – this is likely to be a popular approach that is already being implemented, to decarbonise heating in many urban settings.

[8] “Mitigating heat demand peaks in buildings in a highly renewable European energy system”, Elisabeth Zeyen, Veit Hagenmeyer, Tom Brown,

Supplementary material

Thanks also to Lisa Zeyen for private communications regarding these results, although I naturally suggest readers access the original work to get a full and complete understanding of the results. I hope I have not misrepresented them!


A. Published 8th November 2021: A Progress report on improving Energy Performance Certificates (EPCs) in the UK. This is positive news. The devil will be in the detail, of course, but encouraging.

B. The latest Government (BEIS) research concludes:
“Decarbonised electricity offers the promise of very low or even zero-carbon heating for homes – without necessarily carrying out extensive deep retrofit work. This project shows that Great Britain’s homes can convert to electric heating at a cost far lower than the accepted wisdom. This can be achieved with no threat to comfort, and greenhouse gas emissions will fall very dramatically as a result.”

and tellingly also concludes:

“The work focused on total costs of ownership over 15 years. For most house types and most electric heating systems, the cost-optimal packages of measures have very limited fabric improvements – most commonly just draught-sealing and top-up loft insulation. High-cost improvements, like internal or external wall insulation, hardly ever repay the capital costs over 15 years.”

Although some might argue with the 15 year time horizon, this is hardly a slam dunk for deep retrofit; quite the opposite.

C. On the interesting question of continuous versus intermittment heating when using a heat pump Nicola Terry (in “Will heating your house constantly use more energy?”, 12th January 2022) clearly comes down in favour of continuous heating (the main reason being the relative inefficiency when a heat pump has to heat a house from cold/ colder state).

D. ‘Insulation only provides short-term reduction in household gas consumption’, Cristina Penasco and Laura Diaz Anadon, 1st January 2023,

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Is 2°C a big deal?

Alok Sharma, President for COP 26, told a recent meeting:

“Every fraction of a degree makes a difference”

Reported by  Shaun Spiers, Executive Director of Green Alliance UK, on Twitter (@ShaunSpiers1, 5th October 2021.  

Alok Sharma talked powerfully of the real impact of climate change across the world. Richer countries have a moral duty to act, and it’s in their self interest. 

Roger Harrabin, the BBC’s Energy & Environment Analyst since 2004, responded:

“This is such a hard concept to get across. @AlokSharma_RDG is right – every fraction of a degree really does matter. But how to you explain that to the public who may not even take off a layer of clothing for  two degrees?”

I would direct Roger and anyone else seeking an answer to Katharine Hayhoe, who is the supreme master of communication on such questions. Her short video “What’s the Big Deal With a Few Degrees?” answered the question in a very accessible way.

1°C is already big deal

As Katharine Hayhoe concludes, the Earth is already “running a temperature”, and on Twitter said:

“Using our body temperature is one simple and surprisingly relevant analogy. A fever of 2°C has significant, noticeable, and if sustained long-term, dangerous impacts on our health & well-being.”

The Earth System is very complex, and so is the human body. Part of this wonderful complexity is the ability to self regulate. Under normal conditions this manifests itself as a stable system in dynamic equilibrium, albeit with minor variations and cycles (such as the seasons and mentrual cycles).

Since the end of the last ice age, the concentration of carbon dioxide in the atmosphere, and hence the global averaged temperature of Earth (not to be confused with weather), has remained remarkably stable, despite large flows of carbon associated with the carbon cycle (which tend to cancel each other out). Human civilisation and its agriculture have emerged over 10,000 years, benefiting from this largely stable climate.

Human emissions since the industrial revolution about 200 years ago have now increased carbon dioxide concentrations in the atmosphere by 1/3rd from 280 parts per million to 414 ppm [1]. This is level is more than at any time in the last 2 million years [2]. 

This is already causing a major disruption in the delicate balance that has existed in pre-industrial times, and we are already seeing the impacts in the increasing frequency and severity of extreme weather events. Each fraction of a degree is important in limiting the damage.

To explain what seems at first to be such a surprising consequence from such a small change is important to realise a few things:

  • the land on Earth is under 30% of the total surface area, and the ocean’s temperature is moderated by the heat capacity of a large volume of water, so land is proportionally more affected.
  • as was predicted in 1967 [3], there is proportionally more warming as you move towards the poles.  This not only warms high latitude regions, but disrupts the jet streams that help drive weather patterns at lower latitudes.
  • the rises in temperature are not evenly spread around the world and in a cruel twist, many regions which are the poorest and least responsible for emissions will face the worst impacts.
  • a shift in the averaged temperature hides a massive increase in the chance of weather extremes.
  • at both extremes of the hydrological cycle (dry regions and wet regions) there is a tendency to magnify these extremes (dry regions get drier, wet regions wetter).
Adapted from Hansen & Sako (2016, 2020)

Even with ‘just’ a 0.9°C increase (relative to pre-industrial, this is a 1.2°C increase) in a global mean surface temperature between the 1951-1980 average, and 2009-2019 average, Hansen and Sako have  shown [4]: 

  • hot summers on land in the Northern Hemisphere already occur twice as often and, 
  • extremely hot summers (like 2003) already at least 200 times more often   

As Katharine Hayhoe explained, a 1°C rise in GMST is an enormous amount of energy. 

The difference between a 1.5°C rise and a 2°C rise is highly significant. The IPCC’s 1.5°C Special Report [5] [6] showed a number of ways in which the impacts of 2°C are significantly magnified compared to 1.5°C:

“At 1.5 degrees Celsius warming, about 14 percent of Earth’s population will be exposed to severe heatwaves at least once every five years, while at 2 degrees warming that number jumps to 37 percent.”

Humanity has left it so late to act that avoiding 1.5°C is now well nigh impossible (according to the IPCC), but we can still decide and act to keep below 2°C, and must avoid the increasingly dangerous higher temperatures.

We are warming very fast

Climate change is happening in a mere flick of the fingers on geological timescale.

Going back as far as the emergence of Homo Sapiens less than 300,000 years ago, the rate of increase in carbon dioxide levels has never been this fast, and the global mean surface temperature has never risen this fast.

It got me thinking about how to articulate why the current rate of change is truly unprecedented.

It is important to note that there is usually an initiating cause of a global warming episode in Earth’s deep past – such as orbital changes that provide the drum beat for ice ages, or even earlier, extreme volcanism. But the main cause of the warming has without exception, since life has existed on Earth, been the release of greenhouse gases. These have been principally carbon dioxide and methane released over thousands of years (short on geological timescales).

Our current situation is quite different for 3 reasons:

  • The initiating cause and the main cause are one and the same: human caused emissions of carbon dioxide from fossil fuels (3/4 of the problem) and emissions of greenhouse gases from agriculture (1/4 of the problem).
  • The period over which this is occurring is an instant in geological terms, just 200 years or so since the start of the industrial revolution,
    • whereas for the exit from the last ice age, it took 8,000 years [8]
    • another analogue to the current fast warming is the PETM (Paleocene–Eocene Thermal Maximum) with an initial burst of greenhouse gases and warming over a period of between 3,000 and 20,000 years [9]
  • Human choices are the ultimate cause, and we can stop it.

Currently we have warmed by about 1.2°C in less than 200 years. 

The rate of increase in carbon dioxide concentrations is a useful indicator of risk, because it is the doubling of concentrations that give rise to an increment of warming of about 3°C. Only by stopping emissions can we stop further warming.

The rise in CO2 concentrations averaged over 200 years is 0.67 part-per-million per year (ppm/yr), which is unprecedented. The PETM higher rate of rise of 0.42 ppm/yr comes close, but the exit from the last ice age is much slower, at a rate of 0.01 ppm/yr.

If we continue on the high emissions path we are on, we could reach 4.4°C of warming (3.3°C – 5.7°C range, relative to pre-industrial) [10]. 

This results from a further increase on carbon dioxide concentrations at a rate of 9 ppm/yr [11], which would far exceed even the upper estimates of the rate of increase during the PETM.

I have summarised all this in the following table.

Rate of change of carbon dioxide concentration currently compared to prior events (Richard Erskine, 2021)

I wonder how anyone can imagine we are not in a climate emergency looking at this table.

(c) Richard W Erskine, 2021.

[correction – I transcribed the wrong numbers from the table to the narrative for duration of PETM pulse – now fixed]

. . . o o O o o . . .


  1. See atmospheric Carbon Dioxide (CO2) levels, 1800–present,  (original sources NOAA and NASA).
  2. The IPCC states “In 2019, atmospheric CO2 concentrations were higher than at any time in at least 2 million years” (in Ref. A, section A.2.1)
  3. Manabe and Wetherald in 1967 published results using the first full model of the greenhouse effect including radiative, convective, and other key aspects, to model the greenhouse effect on earth (Manabe having received a share on the 2021 Nobel Prize in Physics for his contributions)
  4. James Hansen and Makiko Sato published estimates in 2016 (Ref. B). These have now updated in 2020 in, see 
  • Hansen and Sato use baseline 1951-80, which is 0.3°C above the accepted Pre-industrial baseline. So the 0.9°C of warming to date, is equivalent to 1.2°C relative to pre-industrial.
  1. See IPCC Reference C, and and useful summary by NASA, Reference D.
  2. Global Warming of 1.5C, A Special Report by the IPCC 
  3. During a much earlier period in geological history, about 56 million years ago, when the world was already warm and ice free, there was an event that lead to extremely fast (in geological terms) warming. It is called the Paleocene–Eocene Thermal Maximum (PETM). This is described by the IPCC as follows (Ref. A):

“A geologically rapid, large-magnitude warming event at the start of the Eocene when a large pulse of carbon was released to the ocean-atmosphere system, decreasing ocean pH and oxygen content. Terrestrial plant and animal communities changed composition, and species distributions shifted poleward. Many deep-sea species went extinct and tropical coral reefs diminished.”

  1. The Last Glacial Maximum was 23-19 thousand years ago (Reg. A). The current period of interglacial temperatures has lasted 10-11 thousand years. I take 19-11=8 thousand years are the period of exit from the last ice age.
  2. For PETM, numbers taken from IPCC (Ref. A) are: 900->2,000 ppm CO2 (sect; 0.04-0.42 ppm CO2/yr(Table 2.1) and estimate of 5°C (4°C – 7°C  range) globally averaged warming (sect Although a new study (Inglis (2020) suggests greater warming.
  3. The SSP5-8.5 high emissions scenario gives rise to a warming of 4.4°C [3.3°C – 5.7°C range] relative to pre-industrial by 2100 (see Table SPM.1 in Reference A).
  4. Box TS.5 in Ref. A indicates SSP6-8.5 would have cumulative emissions of 11,000 GtCO2. But Figure SPM.7 has 38% of these emissions absorbed by ocean and land/biosphere, so 0.62*11,000=6,820 GtCO2 CO2 remains in atmosphere (for a long time). Now Mackay noted “A useful way to calculate things is to remember that 127 part per million (ppm) of CO2 in the atmosphere equates to 1000 GtCO2”, so 6,820 GtCO2 equates to 6.82 * 127 = 866 ppm CO2. We need to add that to the pre-industrial level of 280, giving a total 1146 ppm CO2. Now, dividing this by 80 years (2020 to 2100) gives 9 ppm CO2 per year on average. Note that this case includes high GHG emissions, but also incorporates a reduced level of take up of greenhouse gases in the oceans, land and biosphere (something that many who criticise this scenario as ‘pessimistic’ fail to grasp).


A. IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu and B. Zhou (eds.)]. Cambridge University Press. In Press.

B. James Hansen and Makiko Sato (2016) Environ. Res. Lett. 11 034009

C. Global Warming of 1.5C, A Special Report by the IPCC

D. Alan Buis, A Degree of Concern: Why Global Temperatures Matter, NASA, 19th June 2019

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UK Hydrogen Strategy

The UK’s first hydrogen strategy was issued this week. It caused a lot of heated debate.

This is in the context of the latest IPCC Report. Commenting on it Dr Emily Schuckburgh noted in Carbon Brief:

“Ever more certain, ever more detailed. That’s the brief summary I would give the AR6 WG1 summary for policymakers (SPM). Once again it provides a comprehensive chronicle of extreme weather induced by climate change and the risk of catastrophic future impacts. It estimates the remaining carbon budget from 2020 for a reasonable chance (67%) of limiting warming to 1.5C is 400bn tonnes of CO2 (GtCO2). With global emissions in 2020 of 40 GtCO2, this re-emphasises that this decade is critical”.

There is no dispute that hydrogen will play an important role in decarbonising some areas of the economy, especially hard to deal with ones like steel and fertiliser production.

But the report is a little disappointing in sitting on the fence on a number of issues, notably transport and heating, where there is doubt as to the role hydrogen will play. The report says (p. 62):

“Before hydrogen for heating can be considered as a potential option to decarbonise heat in buildings, we need to generate further evidence on the costs, benefits, safety, feasibility, air quality impacts and consumer experience of using low carbon hydrogen for heating relative to other more established heat decarbonisation technologies.”

And (p. 65):

“We recognise that the longer-term role for hydrogen in transport decarbonisation is not yet clear, but it is likely to be most effective in the areas where energy density requirements or duty cycles and refuelling times make it the most suitable low carbon energy source. 

But despite these sensible cautionary words, the report goes on to try and give the impression that domestic heat and transport are still in play, given more research. But are they?

In the area of cars, many car manufacturers have halted or are cutting back R&D on hydrogen fuel cell cars. One of the issues is the relative inefficiency compared to Electric Vehicles (EVs), but building out the infrastructure is another concern.

“You won’t see any hydrogen usage in cars,”

said Volkswagen chief executive Herbert Diess, speaking to the Financial Times, adding that the idea of a big market for hydrogen fuel cell vehicles is …

“very optimistic … not even in 10 years, because the physics behind it are so unreasonable,”

For heating, if we were to use ‘Green Hydrogen’ (created via electrolysis using renewables) to heat our homes, it would require nearly 6 times as many wind turbines compared to directly using the electricity to power heat pumps (which harvest ambient energy in the environment, and so are much more efficient) [1]

The Committee on Climate Change rather highlighted this in their 6th Carbon Budget where they state (for their ‘balanced pathway’):

“By 2030 37% of public and commercial heat demand is met by low-carbon sources. Of this low-carbon heat demand 65% is met by heat pumps, 32% district heating and 3% biomass. By 2050 all heat demand is met by low-carbon sources of which 52% is heat pumps, 42% is district heat, 5% is hydrogen boilers and around 1% is new direct electric heating.”

Or as Professor Cebon said in the Financial Times:

“Hydrogen should be used only as a last resort for sectors that have no option to electrify … Directing public funds towards hydrogen in sectors that have  more effective alternaive solutions is a mistake”.

In other news, Octopus Energy will soon be making a major announcement on heat pumps (they have been teasing the market on Twitter), and are expected to offer a much reduced cost for components and services, to provide a mass market offer. If the Government comes through with an up front grant of several thousand pounds for installation of heat pumps (air source), to replace the Renewable Heat Incentive (which expires in March 2022), this could be a game changer (in terms of mass adoption).

It has been a turbulent week for hydrogen. 

Chris Jackson, chair of UK Hydrogen & Fuel Cell Association Chair has stepped down owing to the Government’s continued support for ‘Blue Hydrogen’ (derived from natural gas, and which involves burying a by product, carbon dioxide, using a method called ‘carbon capture and storage’ that has not yet been proven at scale, but is being pushed by fossil fuel companies like Shell). Chris Jackson said:

“I would be betraying future generations by remaining silent on that fact that blue hydrogen is at best an expensive distraction, and at worst a lock-in for continued fossil fuel use,” 

It feels like the debate over hydrogen will continue, just as it has been for decades, with fossil fuel interests continuing to try to shape the debate in their favour, with arguably far too much influence in policy circles.

In the meantime we need to decarbonise fast, and we don’t have time to waste – just 10 years to put a serious dent in emissions as the IPCC has indicated. Do we really have the time to keep kicking the hydrogen can down the road?

They say the market will decide.

The good news is that for both cars and heating we have electrification solutions (EVs and heat pumps) available, and they are growing in popularity.

Maybe the market already has decided.

(c) Richard W. Erskine, 2021


[1] “Hydrogen: A decarbonisation route for heat in buildings?”, LETI, February 2021,

(based on original work by Professor Cabon – see )

Figure from the above report. For ‘Green Hydrogen’ we would need a factor of 270%/46% more renewables generation to match the heat provided by heat pumps, that is, nearly 6 times as many off-shore wind turbines operating in winter when we need the heat, for example.

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Is individual behaviour the solution to climate change?

The short answer is: no and yes.

There is a lot of debate about the role of individual actions in relation to climate change. Allegra Stratton was rightly mocked for suggesting people should refrain from rinsing plates before they are put in the dishwasher. Michael Mann makes a much more serious point, saying that fossil fuel interests – having moved on from climate science denial – are,

“trying to convince people that climate change is not the result of their corporate policies but of our own individual actions” (Scientific American, January 12, 2021)

And of course, Michael Mann does not say that behaviour change is unimportant, but it should not be used to distract us from the much bigger actions that large organisations (especially fossil fuel ones), supply chains and Governments must take.

Whilst others stress the importance of systems change, and the coupled role of behaviour change. Lloyd Alter writes that behaviour change is important:

… because we have to stop buying what the oil and car and plastics and beef companies are selling; If we don’t consume, they can’t produce. It makes a difference; I vote every four years, but I eat three times a day.” (Treehugger, May 11, 2021)

And we have to recognise there are limitations to personal actions when not supported by the system. If I want to ditch the car and take an EV bus to go to work 10 miles away, I cannot do that if there is no EV bus (and maybe no bus at all, at the times I need them).

So, at whatever scale we look at it, and through whatever ‘lens’ we choose, we see the connectedness of actions by individuals, businesses, public institutions, local government, national government and multi-nationals.

I want to show at the scale of a town, how we might think about the power that resides in the hands of individuals; and they can possess multiple persona. Yes, they are consumers, but they are so much more. They are voters, employees, church-goers, parents, children, neighbours, and so much more.

If we break the silence and talk about climate change – not the science but what it can mean in terms of progressive action – it’s amazing how easy it is to start a conversation.

We need to think about the ‘agency’ that individuals possess, within the network of actors in a local community. The influence they have is much more than the narrow framing of consumerism. We see a richer systems view of influence and reinforcing feedbacks, with multiple actors involved, and individuals taking on a variety of personas. Here is a little illustrative doodle I created:

Each of these actors can be self-reinforcing too. The householder can influence a neighbour, just by chatting over the fence (I left out these little looped arrows, to avoid making the schematic too busy).

A climate action group (not shown) can – if it is being effective – engage with all the actors in this schematic by various methods and channels, by networking, engaging, and promoting interactions between them.

For example, holding a fair on house retrofit, and inviting relevant businesses, community groups, councillors and the local member of Parliament. If you don’t ask, you don’t get, my mother used to say!

This does not mean that personal action is unimportant – far from it – but when it can be seen as part of a collective goal to promote changes throughout the system, it is far more powerful. While personal actions today might only impact a fraction of the UK’s carbon footprint directly, indirectly it can have a much greater impact. System change (access to low carbon transport, help with decarbonising heating, etc.) together with personal choices is of course where we need to get to for a high impact on emissions.

The individual will also begin to realise the agency they have to promote not just change, but system change.

(c) Richard W. Erskine

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When does it make sense to switch to a heat pump?

Chris Mason on BBC News at Ten (tonight, on 9th August 2021, the day that the IPCC published the science part of their 6th Assessment Report) stated that (in relation to heat pumps):

“you need lots of insulation to make them work”.

This is completely false: you can heat any building with a heat pump that you can with a gas boiler. Why do BBC reporters keep repeating these myths?

In fact, and in the context of the IPCC report, if one’s main concern was the household carbon footprint, a heat pump would be the first thing anyone would do, as I showed here (given the diminishing carbon intensity of the UK’s electricity grid).

The counter argument commonly used is that the costs of running a heat pump (given today’s unit price for electricity) is unaffordable unless there is huge levels of insulation. Of course if we had a fair fight between gas and renewables, electricity prices would come down relative to gas.

But simple maths shows that even at current gas and electricity prices, if one were to replace an old 70% efficient gas boiler with a modern air-source heat pump (ASHP), then the running costs would not be any greater, with only modest insulation measures, as shown here.

A heat pump can heat any home that a gas boiler can. But it makes no sense to try to heat a barn – with a heat pump or a gas boiler! Insulation and draught reduction make sense – and help improve the comfort of a building – and so ‘fabric first’ is an important message. This leaves open the question: how much insulation a householder considers before they invest in a heat pump?

Depending on how an individual wants to spend their retrofit budget, there will be a cross-over point where acquiring an ASHP will trump any further increment in fabric spending. Adding fabric measures will reduce the size of the heat pump required, but only to a point, as there are some base costs for the system, and we need hot water whatever the state of the fabric.

There are small and large houses, well insulated ones and leaky ones. How do we make sense of the numbers?

A useful metric is the heat energy required to heat one square metre of a home per year (this is measured in kilowatthours per metre square per annum, or kWh/m².a). The average UK house – because our historic housing stock is quite leaky – requires about 130 kWh/m².a. The Association of Environmentally Conscious Builders (AECB) aims, when insulating homes, to reduce this measure to 50 kWh/m².a, although might accept as much as 100 kWh/m².a in the case of (say) a Listed Building. A new build Passivhaus aims to achieve just 15 kWh/m².a.

It is easy to work out what figure currently applies to your house.

Look at your annual energy bills. If heated by gas look at the kWh total for the year. Make a guesstimate for how much of this is space heating, say 80% in the current case. Now divide this figure by the floor area of the home. The question then to think – with the help of a retrofit assessor – how far you can reduce this number.

If you currently have poor loft insulation, then fixing this is relatively cheap and has great pay back. Similarly for cavity wall insulation, and for reducing draughts from doors and windows. You don’t need to rip out your sash windows and replace with double glazing; window brushes, and secondary glazing can make a great contribution with a modest investment. Pragmatism is often required, when assessing where you can get the ‘biggest bang for your buck’.

The other key idea is to think in terms not of ripping out things, but taking opportunities when they arise. So, if a new kitchen is being fitted, then why not use the opportunity to insulate that cold back wall, and maybe even consider underfloor insulation and heating? This is why retrofit can often best be seen as a journey to be followed over a number of years.

What follows is an illustrative schematic showing the balance between the money spent on fabric measures (solid line) and what would need to be spent on an ASHP system at a given level of heat demand. As the heat demand reduces (as a result of fabric spend), so does the cost of the ASHP system (including the heat pump and radiators). The schematic envisages a 4-bedroom semi-detached house with solid walls and poor insulation that is hard to treat, and starts (at the left hand side of schematic) with a terrible figure of 200 kWh/m².a [the numbers are illustrative only – each house is different]:

We then start to move from the left towards the right. Spending even modest money on fabric will mean that the size (and cost) of the heat pump system you might buy progressively reduces (e.g. there is a big drop if one moves from a cascade heat pump system to a single heat pump).

At some point, the marginal cost of incremental insulation will rise above the cost of an ASHP (when the solid line cross the dashed line). For example, replacing all the windows with double or triple glazing is a non-trivial expenditure.

And of course, to try to turn a leaky Victorian house into a Passivhaus makes little sense, so there are natural constraints in how far one goes, depending very much on house and site specific factors.

Some people may decide to adopt the ASHP early for a number of reasons (they need to replace an old gas boiler and care about the climate future, or they live in a house in a conservation area where measures like external wall insulation will not be accepted). They may live on a terrace and external wall insulation for one house without the whole terrace joining in, would meet a lot of resistance (including from the planning department). For whatever reason they make their choice, I call these, ASHP ‘eary adopters’.

On the other hand, they may live in a house that can absorb a lot of retrofit insulation measures – perhaps as new owners wanting to start with a ‘blankish’ canvas – and with the help of a retrofit assessor/ expert, strive to get to the AECB 50 kWh/m².a figure. Let’s suppose they don’t have constraints such as conservation issues to deal with. We might call them ASHP ‘late adopters’.

In practice, householders will be somewhere on a spectrum between these two example – in a decision spread zone. A whole set of factors may come into play in their decision making: wish to improve comfort, or reduce carbon emissions, or concern over gas prices in the future, to name just a few.

It therefore makes no sense to say “you need lots of insulation to make them work”.

No, you need “a sufficiency of insulation” to make the running costs “fit your expectations”, and everyone may arrive at different expectations.

But don’t try to heat a barn, with a gas boiler or a heat pump.

(c) Richard W. Erskine, 2021.


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Fantasy maths from the National Farmers Union

Soil carbon is important but it is staggering that both Minette Batters and Prince Charles have made unchallenged statements on @BBCr4today (14th July 2021): That some (livestock) farms are already carbon neutral and that soils could take up 70% of the world’s emissions.

This is all in an effort to promote sustainable livestock farming. Like Graham Harvey in his book ‘Grass-Fed Nation’ they have been seduced by the claims of Allan Savory; but these have been thoroughly debunked by the Food Climate Research Network (FCRN)

The fallacy rests on a confusion between fast and slow carbon cycles, between carbon stocks and flows, which with a little bit of naive maths creates a myth that now permeates the NFU’s PR on the future of farming.

We need better soil health to reduce net carbon release in a warming world, but it is no good using this as a ploy to retain high levels of meat consumption; and we need a massive reduction in the consumption trend.

Godfray et al [1] show the path we are on:

Good soil health will help create sustainable arable farming, but not as a silver bullet to cancel our fossil fuel emissions. Massive reductions in meat production mirrors the same reversal that is needed in all sectors of our economy, and it is a fantasy to suggest otherwise.

Efficient land use is also an issue. Today, over 50% of the UK’s land is devoted to livestock (and this does not include the foodstock we import to supplement their diet), and we import over 40% of our food. To be more self reliant, we have to make a radical shift in diet and land use, as the Centre for Alternative Technology clearly demonstrates in their report Zero Carbon Britain: Rising to the Climate Emergency from which the following Figure is taken:

Livestock reduce the efficiency of calories produced per hectare [2], which is a major issue when it comes to feeding the world.

In the context of the climate emergency, the other issue is that livestock makes a high and increasing contribution to our carbon emissions [1]:

Trying to hide these emissions amongst some warm aspirational words about regenerative livestock farming in idyllic English countryside, is pure delusion (as well as being heavily funded PR), with no scientific basis.

It is such a shame that the NFU (National Farmers Union) are promulgating junk science to advance their meat-first agenda, and it seems that Prince Charles is also on board. 

. . . o o O o o . . .

Science references:

[1] Godfray et al., ‘Meat consumption, health, and the environment’, Science 361, 243 (2018)

[2] Cassidy et al., ‘Redefining agricultural yields: from tonnes to people nourished per hectare’, Environ. Res. Lett. 8 (2013) 034015

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My First Oil

Having worked with acrylics, watercolours and pastels for some years, I decided, finally to take the plunge and start to use oils. The scene is the view across to the River Severn and Wales from Selsey Common.

I’m still pinching myself that I managed to pull this off. 

The foreground gave me the heebie-jeebies.

Grasses were quite straw like with subdued green, and there was lots of undulations.

I remembered to use a little red to ‘knock back’ the greens, and then added combo of yellow ochre and white to progressively lighten it; and some raw sienna in the other direction (to darken), maybe a smidgen of red too in places.

Also, some slightly larger brush strokes in the foreground to suggest more resolved grass.

I remembered to ‘think tonally’ to observe and think about light and dark – there was a huge range to cope with here. I used some Prussian Blue to help with the deep shadows.

The distant fields was just a kind of noodling around trying to get a sense of distance – so cooler, more muted and less defined the further away.

Wales is just a light purple sliver beyond the Severn, which itself is just a hint of reflected light.

The two fields on the right were compositionally crucial to me as they helped establish a near-ground scale beyond the foreground.

Some flecks of white on the mid distance right for buildings – never forgetting the power of gestalt to allow the viewer to see what their mind reconstructs based on the tiniest of visual clues.

The sky was a struggle – I miss the dynamism of working with acrylics or watercolour, so need to practice my skies – but the good thing is that the dark clouds suggest a darkening of the distant land below, and the few yellowy green bright streaks suggestive of sun breaking through on some fields. A little green in the sky is another fully transferrable trick of the trade.

The foreground is in full sun with slopes facing the sun almost white.

The pros of oils are also the cons.

You can keep fiddling for days if you want (although I finished this over 5 hours on and off); so blending on canvas, and wiping away sometimes, is all possible. Acrylics allow for multiple layers and drying in between, with spraying and all sorts of jiggery-pokery; but the palette needs constant attention to stop it drying out. I think they are both wonderful – its like trying to choose a favourite dish – why choose?

I think I’m going to fall in love with oils … just like I did before with acrylics, watercolours and pastels!

(c) Richard W. Erskine, 2021

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Are Air Source Heat Pumps (ASHPs) a Silver Bullet?

According to the Committee on Climate Change heating our homes makes up 40% of our energy use and 20% of our carbon footprint. While there have been dramatic improvements in building standards since 1970 there remains a legacy of poorly insulated homes.

Retrofitting our often old housing stock to reduce heat loss is crucial, but we also need to stop using natural gas as the source of heating if we are to have any chance of meeting our goal of halting global heating. 

It got me thinking about this question – if someone asked about retrofitting their house, and was motivated by the desire to reduce the carbon footprint of heating their home: 

what is the first thing they should do?

It may seem a somewhat artificial question, because in any real world situation, several measures are likely to be advisable, but bear with me.

Many retrofit professionals repeat the mantra “fabric first”, which means, focusing on insulating the building, dealing with leaks, and so forth. This sounds like good advice, given that the cost of some measures, like insulating a loft, are relatively cheap and deliver big savings in carbon emissions.

However, in many cases this is expressed in stronger terms, like “deep retrofit”, which can mean doing everything possible to reduce the heat loss of a building. This could include external wall insulation to homes with solid walls (which cannot benefit from cavity wall insulation), new windows, and dealing with associated issues related to moisture, for example. This school of thought suggests that we should only consider using a heat pump after deep retrofit is complete [Note 1]. 

The mantra “fabric first” then effectively turns into fabric only, because it is not difficult to exhaust a householder’s retrofit budget with changes to the fabric of a building. 

So why should we be considering heat pumps alongside changes to the fabric of a building? 

A heat pump harvests the ambient energy outside a house – either from the air, the ground or water. This ambient energy comes from the sun (when the ground is used as a source it is never deep enough to harvest energy from the core of the Earth, even with a bore hole, and is simply extracting energy from the ground that has been warmed by the sun and stored there). 

For every unit of electrical energy put in to drive the heat pump, it is able to deliver at least 3 units of heat energy into the home. A nice simple explanation of this process is provided here.

Professor David Mackay wrote in his seminal 2010 book Sustainable Energy without the hot air (p.151):

“Let me spell this out. Heat pumps are superior in efficiency to condensing boilers, even if the heat pumps are powered by electricity from a power station burning natural gas. … It’s not necessary to dig big holes in the garden and install underfloor heating to get the benefits of heat pumps”

He was calling for the adoption of Air Source Heat Pumps (ASHPs). He didn’t use the words ‘silver bullet’ but it is clear he was a big fan and frustrated at the low level of take-up. As he wrote 

“heat pumps are already widely used in continental Europe, but strangely rare in Britain”.  

I thought about how to present some information to help explore the question I have posed, and compare fabric related measures to an ASHP. I took data from the Energy Saving Trust website for a typical semi-detached house and plotted the capital cost of different interventions against the annual carbon saving that would result.

The capital costs are indicative and include the parts and labour required.

The only change I made to the Energy Saving Trust data was I reduced the savings for an Air Source Heat Pump (ASHP) from about 4.5 tonnes of CO2 to about 3, because that better reflects the carbon intensity of the national grid in the UK in 2020.

I also indicate the level of disruption involved with colour coding, because this can be a factor in a householder’s decision making. The graph is based on the data tabulated in the Table at the end of this essay [Note 4] (click on image to see higher resolution):

This householder is aiming for the highest carbon saving, and there is only one answer glaring out at you from this graph: the ASHP.

If I change the question slightly we get a more nuanced answer:

what is the first thing they should do, based on carbon reduction ‘bangs for your buck’?

The ratio of the annual carbon saving to the capital cost is a measure of ‘bangs for your buck’.  On this criterion, it makes sense to do the low hanging fruit of loft insulation and fixing drafts, but then once again the ASHP scores very well (this allows for the fact that typically more than half the radiators will need to be upgraded [Note 2], and are included in the cost estimate).

Whereas external wall insulation would typically be similar in cost to an ASHP, but deliver only a third of the annual carbon saving and be a much more disruptive intervention; and in many cases not one that is practical to implement.

A counter argument would be that if we did manage (for a solid walled home) to do all the fabric related measures, we would achieve about 2,400 kgCO2/yr carbon saving (over half the current emissions of 4,540 kgCO2/yr) for an outlay of about £18,500; and then the ASHP could be added and would then ‘only’ need to deal with the remaining half, and that could mean that a lower capacity heat pump could be installed, reducing its cost somewhat.

Each situation will be different and depend on what interventions are possible. If a building is listed and external installation is prohibited (and the alternative of internal insulation dismissed), then the fabric related measures would then total 1,500 kgCO2/yr, leaving two thirds of emissions to be dealt with. 

In either case, in order to maximise the emissions reduction one would require a heat pump.

My argument is not that you must fit a heat pump first, but that you should consider all the available options and to think about a plan (possibly over a number of years). 

I went on to plot another graph where I included the following additional features:

  • To show the ‘best’ reasonable case fabric interventions (which would raise the cost of say, wall insulation, but at the same time increase the carbon saving). 
  • To include a Ground Source Heat Pump (GSHP) option, either with horizontally laid slinkies, or using vertical bore hole(s).
  • To show what happens as the UK electricity grid moves from 2020 carbon intensity levels to being 100% green.

The following illustrative graph was the result:

There are a number of interesting observations based on this graphic.

  • Firstly, as the arrows show, we can increase the carbon savings for each fabric related measure, but these improvements come at extra cost. There will be some trade off for each householder situation as to how far they can go.
  • Secondly, once you have a heat pump, the annual carbon saving will increase every year as the grid gets greener (as it has been in the UK), without the householder having to lift a finger.
  • Thirdly, while a GSHP may have a better performance than an ASHP, it is likely to be quite limited [Note 3], and as Paul Kenny said in his talk to Carbon Coop ‘Heat Pumps – Learning and experiences from Ireland’, if you have extra money spare, why not do the easy thing and spend it on further upgrades to radiators, when you can achieve a target COP without the major disruption and risks associated with a GSHP project (assuming that is even an option).
  • Fourthly, a borehole GSHP is even more costly, and more risky. There are significant risks associated with, for example, drilling into water tables, but the real killer is the cost. For a single householder it makes little sense. Of course, one can imagine scenarios where several houses could share the costs, but these are likely to be exceptional projects; not the basis for mass roll-out of heat pumps.

Some will argue that an ASHP requires supplementary heating during very cold spells in winter. However, in the same talk referred to above, Paul Kenny used data from a significant number of retrofits in Ireland that had ASHPs, using a design parameter of -3°C for cold winters. When the beast from the east came and these houses experienced -6°C, they were all fine and did not require supplementary heating. He wrote a piece on LinkedIn about this experience, which flies in the face of much of the ‘received wisdom’ in the retrofit community.

And in the UK, without the much larger grant that GSHPs enjoy, as compared to ASHPs, it is doubtful there would be anything other than a marginal role for GSHPs. It will be no surprise if ASHPs dominate the heat pump market in coming years and for some installers, this is already the case.

So, are Air Source Heat Pumps a silver bullet to decarbonising the heating of homes? 

One has to say in many ways they are!

But of course, in reality, it makes sense to consider them in the mix of other retrofit measures, and to carry out some improvements to the fabric of a building as part of a ‘whole house’ plan.

We just shouldn’t let the ‘deep retrofit’ mantra put people off considering an ASHP; maybe even as one of the first things you do.

(c) Richard W. Erskine, 2021


1. While I am a huge fan of PassivHaus and similar standards, we must remember that these standards cannot easily be applied to existing stock, and would be hugely expensive. 80% of the homes in 2050 already exist, so 80% of the problem of decarbonising heat in homes is already there; and BRE estimates there are 9 million ‘hard to treat’ homes in the UK.

2. Upgrading radiators is usually required to increase the effective surface area. This is needed because heat pumps operate at a lower flow temperature, and the heat delivered is a function of the temperature of the radiator and its surface area. The surface area can be increased by using 2 or more panels with fins sandwiched between them. This can also help reduce height and width of the radiator that would otherwise be necessary, while making the radiator somewhat deeper / fatter.

3. A GSHP has a better Coefficient of Performance (COP) in winter, an ASHP could do better in Spring and Autumn. The overall Seasonal COP for a GSHP will probably be higher but unlikely to be higher than 15%. We need real world studies to get a good figure here. But the cost of a GSHP using slinkies in 1.2m trenches (for those unusual cases where householders have sufficient land to achieve the area necessary) is something like double that for the ASHP. 

4. Table of Typical three bedroom, solid walled, semi-detached house


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Nuclear weapons and me

Remembering Hiroshima – the dead, the survivors and the blight that nuclear weapons have brought on this world – on this day, 75 years after the first nuclear weapon was used against a civilian population. A weapon, remember, that was developed because of a fear that Nazi Germany would develop it.

Joseph Rotblat, a scientist who I admire so much, left the project to develop a nuclear weapon when it became clear to him that Germany would not be able to develop it. Few if any others on the project possessed his moral vision and authority.

In 1981, Professor Mike Pentz, who led the formation of the OU (Open University) science department, founded Scientists Against Nuclear Arms (SANA). I was at Bristol Uni. doing a Post Doc at the time.

I went to hear him speak. What an amazing and inspiring speaker he was; I signed up on the spot. The cruise missile crisis was in full swing.

Within months it seemed I was on the National Coordinating Committee of SANA.

It kind of killed my passion for science, something I’d been in love with since a young boy. I had a lab when I was just 12.

I left my research in computational quantum chemistry.

I went into the world of industry and in my spare time spent a lot of the 80s working in the background helping to develop tools for the anti-nuclear movement.

This included a Program to assess the impact of nuclear attacks, which I managed to squeeze onto an Amstrad PCW 8256 – with no hard disc and a memory of just 256K! Or 0.25Mb, or 0.00025Gb.

This program was given free to local authorities. 

During this time I had also married the beautiful nurse who I met in Bristol, and we brought up two girls. So Bristol always has a special resonance for me, on so many levels.

Eventually I was pretty burnt out and stepped back from nuclear activism – after all, we got rid of cruise. Job done, right?

If only.

SANA evolved into SGR, Scientists for Global Responsibility, a great organisation that is still going strong and doing good work.

Nevertheless, it might explain why it took a while for me to realise there was another great elephant in the room – global warming. 

This time, it was Naomi Klein, and specifically her book This Changes Everything which was the kick up *** I needed. I have a signed copy from when she spoke at the Cheltenham Book Festival.

Now I spend a lot of my time in retirement on climate change matters, but focusing my efforts on local community action.

I never lost my love for science, even if things turned out different to my boyhood dreams.

But damn you, nuclear weapons, and damn you fossil fuels, and you, the same old, same old vested-interest apologists.


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Angry Weather

Dr Fredi Otto is the Acting Director of the Environmental Change institute and an Associate Professor in the Global Climate Science Programme where she leads several projects understanding the impacts of man-made climate change on natural and social systems with a particular focus on Africa and India.

Her new book, Angry Weather: Heat Waves, Floods, Storms, and the New Science of Climate Change published by Greystone Books is due out on 17th September in the UK (and 2 days earlier in USA), and I for one, can’t wait to read it.

She was interviewed about the book in The New Scientist

Credit: Rocio Montoya

Here’s a short review by Kirkus.

The attribution work Dr Fredi Otto has helped pioneer is extremely important and here’s why …

We need to be able to move beyond the general global trends that have tended to dominate the conversation on climate change. These demonstrate beyond doubt that human greenhouse gas emissions are the dominant factor in creating a warmer world, where extreme weather events are an expected outcome.

What has been harder to assess is the ability to pin a particular extreme weather event on man-made global warming.

I am hoping that this book will help me – and maybe you? – on a journey of discovery, to learn more about advances in our understanding of how to make that link (I am ordering my copy through my local bookshop The Yellow Lighted Bookshop, not Amazon, because (a) I support local businesses whenever I can and (b) YLB are just brilliant!)

In a previous era when smoking and lung cancer cases first began to appear in the courts, the tobacco companies would use the defence that nobody could be sure if this or that particular case was due to smoking or would have happened anyway. It was just bad luck!

No matter that the bad luck was rising exponentially amongst smokers.

The fossil fuel companies can and will use the same cynical defence.

Sir Richard Doll and collaborators did pioneering work to demonstrate the link between smoking and lung cancer in 1950, using novel statistical methods to overcome the charge that ‘correlation does not mean causation’. In this case it most certainly did. Remember, that this long ago, the underlying biochemical mechanisms were not that well understood, and it was 3 years before we had even the basic structure of DNA established, in that seminal year when I was born 🙂

So, climate attribution science – the ability to pin man-made climate change on particular extreme weather events – is a complete game-changer.

The advantage here is that the underlying physical mechanism are extremely well understood, relying on 200 years of accumulated fundamental science. No need here for any new fundamental physics.

But once again, statistics is the hurdle that must be overcome.

Because while at a global level, the uncertainties as to the human causation for global climate change have now essentially decreased to the point where humanity’s fingerprints are all over man-made global warming, as one gets to smaller and smaller scales, the uncertainties mount up, for quite basic statistical reasons.

Once again, innovations are required in order to demonstrate the link at the level of a Hurricane Sandy, or the recent extreme Australian Fire season.

But imagine the implications of being able to make these connections.

We would then be in a position to hold businesses and politicians to account for their inaction, and put a price on the consequential damage, at least in the narrow sense of the quantifiable impact on property; something they at least understand [1].

As Dr Otto says:

“If governments don’t do their job and don’t do enough to put a stop to climate change, then courts can remind them of their purpose.”

So, far from being about some dry technicalities regarding climate attribution and statistical analysis, this book could become part of the tool-kit of everyone involved in action to limit the extent and severity of man-made global warming.

I really hope it does.

(c) Richard W. Erskine, July 2020


[1] It is tragic that we seem – at least in the Anglo-Saxon culture – to put so much more weight on loss of property than loss of habitat or life even, but that bias can be turned to our advantage.

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Following the science: what should that mean?

Following the science and politics

The ‘science’ represents the evidence, the ‘Is’, but we need values, the ‘Should’ to arrive at what’s possible, the ‘Can’, and then leadership, capabilties and capacity to turn that into action, the ‘Will’. Only when the plans are executed is it ‘Done’. The refinement loops come from ‘measure effectivity’ and ‘weigh opinion’, and there will always be a tension – sometimes a conflict – between these.


It has been a mantra repeated every day at the UK Government’s Covid-19 press briefing that they are following, or are guided by the science.

What does this mean or what should it mean?

Winston Churchill famously said that scientists should be on tap, but not on top. 

This meant, of course, that politicians should be the ones on top. 

Scientists can present the known facts, and even reasonable assessments of those aspects of a problem that are understood in principle or to some level, but for which there remain a range of uncertainties (due to incomplete data or immature science). As Donald Rumsfeld said, there are known knowns, unknown knowns and unknown unknowns. Science navigates these three domains.

Yet, it is the values and biases, from whatever colour of leadership is in charge, that will ultimately drive a political judgment, even while it may be cognisant of the evidence. The science will constrain the range of options available to an administration that respects the science, but this may be quite a wide range of options. 

For example, in the face of man-made global warming, a Government can opt for a high level of renewables, or for nuclear power, or for a radical de-growth circular economy; or something else. The science is agnostic to these political choices.

The buck really does stop with the politicians in charge to make those judgments; they are “on top”, after all.

So the repeated mantra that they are “following the science” is rather anti-Churchillian in its messaging.

If instead, Ministers said, “we have considered the scientific advice from the Chief Scientific Adviser, based on discussions of a broad range of scientific evidence and opinion represented on SAGE (Scientific Advisory Group for Emergencies), and supporting evidence, and have decided that the actions required at this stage are as follows …”, then that would be correct and honest. 

And even if they could not repeat such a wordy qualification at every press conference it would be like a proverbial Health Warning – available on Government websites – like on a cigarette packet, useful for anyone who feels brave enough to start smoking the daily propaganda on how brilliant the UK is in its response to Covid-19 (which, despite a lot of attacks on it, has not been as bad as some make out, and the Chief Scientific Adviser (CSA) and Chief Medical Officer (CMO) have rightly gained a lot of credibility during the crisis).

The uncomfortable truth is that ‘following the science’ is about proaction not reaction; about listening to a foretold risk years in advance and taking timely and substantive actions – through policies, legislation, projects, etc. – to mitigate against or build resilience in the face of known risks.

Pandemics of either a flu variety or novel virus kind have been at the top of the UK’s national risk assessment for a decade. Both SARS and MERS were warnings that South Korea took seriously to increase their preparedness. The UK was also warned by its scientists to be prepared. The UK Government under different PMs has failed to take the steps required.

Listening to the science in the midst of a pandemic is good, but doing so well in advance of one, and taking appropriate action is a whole lot better. Prevention is better than cure, is a well known and telling adage.

Of course, the naysayers will come out in force. If one responds to dodgy code prior to 2000 and nothing bad happens, they will say that the Y2K bug was a sham, an example of alarmism “gone mad”; they will not acknowledge the work done to prevent the worst outcomes. Similarly, if we mothball capacity for a pandemic, then once again, expect the charge of alarmism and “why so many empty beds?”.

Our economy is very efficient when things are going well – just-in-time manufacture, highly tuned supply chains, minimal redundancy, etc. – but not so great when shocks come, and we discover that the UK cannot make PPE (personal protective equipment) for our health and care workers and we rely on cheap off-shored manufacturing, and have failed to create sufficient stocks (as advised by scientists to do so).

Following the science is not something you do on a Monday. You do it all week, and then you act on it; and you do this for risks that are possibly years or decades in the future. You also have to be honest about the value-based choices you make in arriving at decisions and not to hide being the science.

Scientists don’t argue about the knowns: the second law of thermodynamics, or that an R value greater than 1 means exponential growth in the spread of a virus. But scientists will argue a great deal about the boundary between the known and unknown, or the barely known; it’s in their nature. Science is not monolithic. SAGE represents many sciences, not ‘the’ science.

For Covid-19 or any virus, “herd immunity” is only really relevant to the situation where a vaccine is developed and applied to the great majority of the population (typically greater than 85%), with a designed-in strong immunity response. Whereas immunity resulting from having been naturally infected is a far less certain outcome (particularly for Coronaviruses, where there is typically a weak immune response).

So, relying on uncontrolled infection as a basis for herd immunity would be naive at best. It is true that it was discussed by SAGE as a potential outcome, but not as the core strategy (as Laurence Freedman discussed here); the goal was always to flatten the curve, even if there was great debate about the best way to achieve this.

One of the problems with the failure to be open about that debate and the weighing of factors is that it leaves room for speculation as to motives, and social media has been awash with talk of a callous Government more interested in saving the economy than in saving lives. I am no fan of this Government or its PM, but I feel this episode demonstrates the lack of trust it has with the general public, a trust that Boris Johnson failed to earn, and is now paying the price in the lack of trust in his Government’s pronouncements.

Yet I do have confidence in the CSA and CMO. They are doing a really tough job, keeping the scientific advice ‘on tap’. They cannot be held responsible for the often cack-handed communications from Ministers, and failure to be straight about PPE supplies and the like.

Some people have criticised the make up of SAGE – for example, because it has too many modellers and no immunologists and no virologists. I don’t understand the lack of immunologists.

Virologists are clearly key for the medium-long term response, but a vaccine is probably over a year away before it could be deployed. So, at the moment, containment of the spread ‘is’ the Emergency, and social distancing, hand-washing, isolation, hospitals, testing, etc. are the tools at hand, and it might be defendable that they are not currently the focus of the discussion.

Groups at Oxford University and Imperial College are being funded to help develop vaccines and to run clinical trials. Virology is not being ignored and it is rather odd to suggest otherwise.  But again, transparency should be the order of the day – transparency on who is invited onto SAGE, when and why, and transparency on the evidence they receive or consider. But having a camera in there broadcasting live discussions may inhibit frank debate, so is probably not a great idea, but the Minutes do need to be published, so other experts can scrutinise the thought processes of the group.

The reason why Dominic Cummings (or any other political role) should not be sitting on SAGE, in my view – even if they make no contribution to the discussion – is that there is a risk (a certainty, probably) that he then provides a backdoor summary of the discussions to the Prime Minister, which may conflict with that provided by the CSA. It is the CSA’s job to summarise the conclusions of the discussion and debate at SAGE and provide clear advice, that the Government can then consider and act on. The political advisers and politicians will have plenty of opportunity to add their spin after receiving the scientific advice; not during its formation or communication.

Now, it seems, everyone agrees that testing and contact tracing will be key tools in ending or reducing the lock down, but of course, that means having the systems in place to implement such a strategy. We don’t yet have these.

The British Army, I understand, don’t use the term “lessons learned”, because it is so vacuous. We have “lessons learned” after every child abuse scandal and it doesn’t seem to make much of a difference. 

A lesson truly learned is one that does not need that label – it is a change to the systems, processes, etc., that ensures a systemic response. This results in consistently different outcomes. It is not a bolt on to the system but a change in the system.

Covid-19 asks lots of questions not just about our clinical preparedness but the fairness of our systems to safeguard the most vulnerable.

Like a new pandemic, the threats from global warming have also been foretold by scientists for decades now, and UK politicians claim to be listening to the science, but they are similarly not acting in a way that suggests they are actually hearing the science.

As with Covid-19, man-made global warming has certainties and uncertainties. It is certain that the more carbon dioxide we put into the atmosphere the warmer the world will get, and the greater the chance of weather extremes of all kinds. But, for example, exactly how much of Greenland will melt by 2100 is an on-going research question.

Do the uncertainties prevent us taking proactive action?

No, they shouldn’t, and a true political leader would take the steps to both reduce the likely size of impacts (mitigations), and increase the ability of society to withstand the unavoidable impacts (adaptation), to increase resilience.

The models are never perfect but they provide a crucial tool in risk management, to be able to pose ‘what if’ type questions and explore the range of likely outcomes (I have written In Praise of Computer Models before).

Following the science (or more correctly, the sciences) should be a full-time job for any Government, and a wise one would do well to listen hard well in advance of having to respond to an emergency, to engage and consult on its plans, and to build trust with its populace.

Boris Johnson and his Government need to demonstrate that it has a plan, and seeks support for what it aims to do, both in terms of prevention and reaction. It needs to do that not just for the Covid-19 crisis, but for the array of emerging crises that result from man-made global warming.

We need to change the system, before the worst impacts are felt.

(c) Richard W. Erskine, 2020.


FOOTNOTE – Sir Mark Walport and John Ziman – on science policy and advice

I listened to Sir Mark Walport a few years ago in a conversation about the role of Chief Scientific Adviser (a post he has held), which was very interesting


[This episode was recorded on July 21, 2016 in front of a live audience at Caspary Auditorium at The Rockefeller University.]

He said that any policy must look at a problem through 3 different lenses:
– Evidence lens
– Deliverability lens
– Values lens

and that science can only help with the first of these.

He made the point that trust in science is very context specific: Science can say anything about the Higgs Boson and be believed, but on an issue like embryology, values kick in and there will be much less trust.

He also makes a strong distinction between ‘pollable’ questions and non-pollable questions. I will give examples.

“does extra CO₂ in the atmosphere lead to increased global warming?” is a non-pollable questions (the unequivocal answer is: yes); whereas “should UK focus on renewables or nuclear power to decarbonise the grid?” is a pollable question (answer: Brits much prefer renewables, by a wide margin).

Scientists need a special range of skills to be able to do the advice job, above and beyond their scientific skills. John Ziman explored the differences between scientific discourse and political debate in his paper (2000) “Are debatable scienti􏰜fic questions debatable?”

Click to access Ziman.pdf

He explains how complex most scientific questions are, with rarely a simple resolution, and conducted in a way quite different to political debate (yet no less argumentative!). The two styles sit awkwardly together.

Yet public and political discourse (especially on social media, but in newsprint, and parliament too) often expects a binary answer: yes or no, right or wrong. Shades of grey are often not tolerated, and if you don’t ‘choose a side’, expect to get caught in the crossfire.

I haven’t read the belatedly released SAGE Minutes yet but I expect there will have been lots of discussions on points where Walport’s lenses (Evidence, Deliverability, Values) sit uncomfortably alongside each other.

At some point, I imagine a fly on the wall, hearing …

“we need to do test, trace and isolate as soon as possible”

“agreed, but we need to recognise the constraint that the test capacity is limited at the moment, so we’ll have to wait till we have flattened the curve enough, to reduce the testing demand, but also build up capacity; meanwhile we cannot avoid a lockdown”

“can someone answer this – how well will the public comply and how would this change the numbers?”

“we ran some sensitivity analysis, and we need very high compliance to make it work”


Leading to a messy compromise set of ‘options’ and scientists NOT the ones with the authority to choose which ones.

The scientists didn’t choose a context where Governments had failed to take on board prior recommendations over some years, to build capacity in PPE, etc. So the advice is very context dependent.

It is highly disingenuous of politicians to say they are ‘following the science’ when that is just one element in the decision making, and where a poor starting position (e.g. the lack of prior investment in pandemic responsiveness) is neither something they influenced, nor can change.

….  o o O o o ….

Updated with Diagram and Footnote on 28th June 2020


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Becoming an artist: fundamentals


“you need three things for paintings: the hand, the eye, and the heart.  Two won’t do.  A good eye and heart is not enough; neither is a good hand and eye”

David Hockney reflecting on the Chinese attitude to art


I wrote about my ‘awakening’ in moving originally from a science background and finding my way to becoming an artist since my retirement.

Art may seem to be completely different to the science I grew up with, because there appear to be no rules. But the artist and scientist do have quite a lot in common, as I discussed previously:

        • a curiosity and playfulness in exploring the world around them; 
        • ability to acutely observe the world; 
        • a fascination with patterns;
        • not afraid of failure;
        • dedication to keep going; 
        • searching for truth; 
        • deep respect for the accumulated knowledge and tools of their ‘art’; 
        • ability to experiment with new methods or innovative ways of using old methods.

The difference is that in science we ask specific questions, which can be articulated as a hypotheses that challenge the boundaries of our knowledge. Whereas in art, the question is often simply ‘How do I see, how do I frame what I see, and how do I make sense of it?’ , then, ‘How do I express this in a way that is interesting and compelling?’.

In art we do not have rules like in science, but in order to make progress, it is important to articulate guidelines, or fundamental principles if you like.

My starting point is a desire to create representational art, but including impressionistic styles, and even abstractions. I am not interested in trying to create a perfect copy of a scene, because as I often say, if that was my objective I would use a camera, not a paint brush.

This is not about being lazy and not wanting to create all that perfect detail, but rather to highlight the fact that a painting is doing a completely different job to a photograph; it is an expression not a record.

This is the second essay in a series I am writing on Becoming an artist, and I want to turn to the fundamentals.

The fundamental principles can be loosely grouped under the following headings:

  • Heart – learning to develop one’s creative impulse;
  • Eye – learning to observe as an artist does;
  • Hand – learning general techniques applicable to any medium.

I cover just those principles that I have internalised particularly over the last few years as a student of Alison Vickery, my mentor on this journey.

I haven’t read Hockney’s reflections on the Chinese artist tradition, but it is curious that I independently – in my first draft of this essay – came up with Practice, Observation and Technique. It was Alison who suggested it fitted well with the Chinese approach that Hockney espouses, so I changed the headings to Heart, Eye and Hand. Maybe these really are universals that any student of painting, from any culture, will recognise on reflection.

I am always questioning things “why do you do that?” or “how do you do that?”, and then trying to find the why behind the why. 

Alison has never written down this list, this is my appreciation of the lessons I have learned, and I am sure I will have missed some important elements out, or presented things differently to how a professional artist like her would articulate things. 

I am sharing my journey and the ideas that have helped me, and so feel free to use and abuse these ideas in your journey.


The emotional side of painting is in many ways the most important. When you feel free to express yourself in the way you want, you are, by definition, an artist. 

While you try to be someone else and to follows somebody else’s standards of what you think you should be and do, then you will struggle to find your voice, and your language for expression. 

Under the heading of ‘Heart’ I highlight the things that most influenced me in finding my voice, which includes aspects of expressiveness.

Loosen up

In sport you need to do a warm up, and in art it is also important to free up any tension in your mind or body.  Try to start a session on a cheap piece of paper first (so you won’t stress about ‘wasting’ an expensive piece of art paper).

Even when doing a piece of work you wish to develop, you still need to be bold and work fast, initially at least, and avoiding tightening up.

Start with the biggest brush you can get away with, hold it loose not tightly.  When you start painting, avoid fine brushes altogether; they will kill your ability to work loose.

For watercolour, try starting with a size 12 brush  – a decent quality one that will hold a lot of pigment but still make a point.

Loosen up. Make mistakes, they may be happy ones.

Work the whole area

The opposite extreme would be to start painting in the bottom left and work your way up to the top right, or for Michelangelo to carve out the perfect head of the David before moving on to doing his willy! No, as with a sculptor, you must ‘chip away’ all over the subject in broad bold strokes.

As you move to less bold and more detailed strokes, still keep working all areas of the ‘canvas’.

A huge benefit of this approach is that you will being to see things that influence how you develop the painting. Maybe you had a preconception of how you wanted to develop it, but you can now see how to make it better.

Don’t be afraid of white space

Working every areas of the paper is not the same as covering every area with paint – it is ok and actually desirable to leave areas of white space (or whatever the background colour might be). You need the light to get in.

White might be used to suggest light falling on a subject; a painted tree might be dark on one side where there is shadow, and white on the other, suggesting light from the sun.

This is particularly important with a medium like watercolour, where you need to compensate for an inherent difficulty in creating good contrast, and the white space can help to achieve it.

Use sketches and studies

As part of trying to get to know the scene better, do several quick sketches or studies, maybe starting with a charcoal drawing, then a very quick watercolour. Give yourself a short time just to produce something. Use cheap paper again.

Perhaps tear off bits of paper and see how it changes your perspective on things.

Mess around. Don’t self censor. Just go for it. 

If you create something that you think ‘that looks interesting’, then cut it out and paste it into an art journal, and add some written side notes “I wetted the paper and dropped in a swathe of cobalt blue, then dabbed it with kitchen towel to create a cloud”. Build up an inventory of such experiments.

Play with composition

After doing an initial sketch of a scene, you can use a ‘window’ cut out of card (with the required aspect ratio for the final painting), placed at different distances from the sketch, and use it to see how much you want to include in the final piece.

Maybe you decide that the house in the foreground is a distraction from the copse on the hillside which is what you really want to be the main focus in the composition.

Learn when to stop

Picasso once said that a finished painting is a dead painting.

It is so easy to over-work a painting, so learning where that inflexion point occurs – between improving a piece and killing it – is perhaps the most difficult skill of all.

Always err on being slightly underdone to overdone.


Painting is not photography. You are not trying to replicate what a camera would see. 

You are creating an impression that speaks to you (and you hope, will speak to others, but that is a bonus). While the work is representational, that does not mean you cannot be impressionistic.

You can decide to remove the annoying road sign that is upsetting the composition; make the clouds more moody; or whatever you care to. But it is important to learn to observe. Having a good eye is as important as having a good brush!

Paint what catches your eye or interests you

It might be the shape of a tree that intrigues you, or the curve of a river, or the curious shape of a cloud, or the tree line on a brow of a hill. Whatever it is, it is a great subject for you, because you are emotionally invested in it.

Learn to be acutely observant

How much time are you spending looking at the paper, and your brush strokes and how much time observing the subject matter? As a novice it is often a 80/20 split in time, when if anything it should be a 20/80 split.

The more you look, the more you see. The brain is telling you that the grass is green, but look closely and in the evening sunlight there seems to be some blue grass in the shadows of the tree – impossible? No, trust what you see.

The light from the window makes the shoulder of the sitter look almost white, but how can that be – they are wearing a black jacket. Look again, trust what you see.

Even if you don’t particularly like drawing, it is worth having a go, because it is another way to help develop one’s observational skills.

Think tonally

It is so easy to become obsessed with finding the right colour to use, but much more important than colour is tone.

Seeing the dark patches lurking in the depth of the wood, and noting that even on the apparently uniformly yellow daffodil there are shades and shadows, that help create a sense of volume; these are example of being tonally observant.

Having a good tonal range can really bring a painting to life.

Doing charcoal studies can really help to develop a sense of tone, unencumbered by considerations of colour.

When preparing to compose a picture, establishing the tonal range of the scene or subject is one of the most important things you can do.

Hard and soft edges

Often we feel compelled to paint or draw a hard edge because our brain says ‘there is a vase there, so I will draw around it’. Look more carefully and the brightly lit side of the vase blends in with the brightly lit background, creating a soft barely discernible edge. Resist drawing what you cannot see!

Look through someone else’s eyes

Take time out to step back, get a sup of tea, and then imagine you are someone else viewing the painting for the first time.

Does it grab you? Have you resolved the different elements of the composition? Have you established a focal point that draws the viewer in?

Look out for symmetry

Humans seem to like patterns in nature and one of the most universal patterns is simple bilateral symmetry – the kind created by the reflection of a scene in a body of water (with a horizontal line of symmetry), or created by the centre line of a tree  (with a vertical line of symmetry).

It can really help draw in the viewer to exploit the symmetries we see around us, in our paintings.


A background may naturally present itself, as in a landscape, but in a studio, doing a still life for example, there may be a white wall behind the subject and little else. To avoid a painting looking flat, it is helpful to create a background, even where none exists. Maybe some imagined shadows or some texture on a wall will help.

Think about how a background might enhance the composition. It is so easy to get lost in a subject in a foreground, and forget how important a background can be in developing a composition.


Most, but not all, of the techniques described below are applicable to any of the painting mediums I have in mind: charcoal, pastel, watercolour, ink and acrylic. 

Later essays will focus on techniques specific to each medium. There are hundred of different techniques and ‘tricks of the trade’ out there. You will never stop learning new ones, but it is easy to get overwhelmed. I have included here the ones I feel are most important, at least to me.

Experiment with mark making

Try using different shaped brush heads, and other tools to create marks on a page.

We cannot all be Van Gogh who created his own brilliant style of mark making, but we can all just have a play.

To illustrate this, think about how you might paint a branch of a tree. You could use a classical pointed watercolour brush and carefully follow a line to mark out the branch. But you might struggle to control the thickness of the branch.

Alternatively, you could use a very wide headed flat brush to create the branch with a single dab of the brush.

Use brushes of different shapes and sizes, twigs, bunched up cloth, sponges, palette knives, or whatever; depending on the medium.

There are no rules with mark making – only that you approach it with confidence – so best to just try out as many variations as you can. Find out what works for you.

Play with negative spaces

A brightly lit vase on a table with a dark background might be approached first by painting the dark background – the vase will appear out of the darkness.

This idea can we be used in different ways, even when doing a simple sketch. Wainwright’s pencil drawings of the Cumbrian hills often include sheep, brightly lit from above. So instead of outlining the back of a sheep, he drew the grassland in the background; a sheep then appears as the negative of the grassland.

Use layering / glazes

When a medium is translucent or thinly enough applied to effectively be so, one can build up multiple layers to create a desired effect. 

In some cases – particularly with pastels – the painting may need to be fixed before proceeding further to avoid muddying the colours.

Surprisingly, even when using a medium as basic as charcoal, it is good to think in terms of layering.

With watercolour, glazes can help to develop depth.

Just as an old piece of furniture develops a patina, a painting can also develop a sense of complexity from multiple glazes.

Thin and thick

In any medium, it is normally best to start thin and only later to use a thicker form of the medium.

In acrylics, this is very important (in oils also, but I won’t be discussing oils in this series); using a more diluted medium at first. But the same applies to watercolours where one starts with light washes on the wet side, and only later might use some gouache on the drier side for some highlights.

The idea applies to pastel painting also. You should use light strokes with the side of a pastel stick at first.

Minimal palette 

Try when working in colour to use a minimal palette. Primary colours and white at a minimum.

It is a great discipline to learn how to make one’s own greens, browns and greys. With 2 yellows and 2 or 3 blues you can make a huge range of greens, for example.  As with all rules, you may want sometimes to break this rule; a ‘sap green’ can be difficult to replicate and is useful for bright foliage.

By using a small palette it makes it easier to tie the painting together, chromatically.

One can always add a few additional hues to finish a painting.

Knocking back

Sometimes a pigment is too bright for the current situation, such as on a grey day in winter. By adding a little of the complementary colour (on the opposite side of a colour wheel), it dulls the intensity of the pigment you are going to use.

With watercolour you can also, of course, reduce the hue intensity by adding white gouache.

Use of resist mediums

A ‘resist’ medium is something you can place on the paper (or canvas, or board) that will not absorb the pigment being applied to the surface. This can be for a range of reasons.

A masking fluid can be used to precisely cover a shape that must remain white in the final piece, or at least, not be covered by whatever is about to be painted over the medium. The fluid must dry fully then be removed by rolling a finger over it. This is ideal, for example, for snowdrop flowers.

The other kinds of resist medium tend to be ones that are used to cover a line or area and remain in place. For example, wax or a clear oil pastel crayon. These can be used to create texture – when wanting to create some extra effects in clouds, or in some landscape or on a building. 

Alternatively, resist might be used to suggest gaps between trees or foreground grasses, or some other effect where you don’t want the background (usually white, but not necessarily so) painted over.

Wet and dry

Particularly with watercolour but also with acrylics, the amount of water used when applying pigment can have a big impact on the picture. There is frequently a benefit to starting quite wet and allowing pigment to flow a bit. This avoids getting hard edges too early in a painting’s development. You can also just drop in other pigments and just see what happens.

You may need to use a hairdryer at some point to allow you to move onto a new wash or glaze / layer.

Later on, it may be you need to do some relatively dry work, dragging a relatively dry and lightly loaded brush – without completely covered the area – in order to deliberately generate striations. In a watercolour, this might be done with water colour pigment added to white gouache, for example.

Dabbing, rubbing and scraping

Sometimes, it is useful to be able to partially remove medium in order to create a necessary effect.

When doing a charcoal sketch, the rubber is as important as the charcoal in building up a patina to develop the image.

In watercolour, a paper towel can be all one needs to instantly create a cloud in a sea of blue that has just be painted.

For acrylic, scraping an upper layer of pigment away – before it has completely dried – to reveal pigment below can be used in number ways, such as helping to suggest a line of trees on the ridge of a hill.

Flicking and spraying

No one wants to paint every leaf on a tree and there is no need to. Look at a tree painted by Turner or Constable and you will see a fair number of brush strokes for foreground trees, to give the impression of detail, without excessive labour, but only broad strokes for distant trees.

Modern painters will often use an additional technique of flicking or spraying pigment to suggest the necessary complexity of the foliage. It can be repeated for different hues to create additional complexity.

Flicking of white gouache, slightly diluted can be used to help suggest the froth of a breaking wave, for example.

It is useful to have a cheap brush with quite stiff bristles (such as one might use for applying PVA in collage; if not available, an old toothbrush will also do the trick), as this allows one to do flicking by merely stroking the bristles (rather than using the wrist), giving much greater control.

Consider the interplay of simplicity and complexity

As we have seen with use of layering, resist and flicking techniques, there are several ways in which to develop complexity, and the human eye is intrigued by complexity. 

That is why we prefer to look at a rusty corrugated tin roof to one that is pristine and uniform. Yet we also like simplicity. A perfectly  rendered blue sky, a flat sea and a wide sandy beach – with just a small sailing boat in the distance – brings a sense of calm.

In developing an idea for a painting we can observe this interplay of complexity and simplicity in the world around us, and then decide how we might render it.

Consider the interplay between precision and imprecision

The painter must choose where to put effort into developing detail.

Typically, the subject is given more attention and other elements of the composition are allowed to be imprecise. A photographer, when doing a portrait amongst a landscape, will often use depth of field to make the background loose focus, and in a way so is the painter, but with greater freedom to emphasise or play with this imprecision. 

It may be that one needs the woodland on the distant hill to frame the picture of the family by the river, but the trick is to be very imprecise in how it is rendered – less is often very much more.

Choice of paper or other surface

There is a bewildering array of different surfaces to paint on. 

Papers can come in different weights and also levels of roughness of the surface.

Pastels require some grain on the surface to ‘take’ the pastel. Watercolour paper can be smooth or mottled and it depends a great deal on how wet you want to work, and whether you find the texture a help or a hinderance.

You will learn about stretching paper, and about priming paper or board with gesso. 

For any single sheet of paper, you need a board and masking tape to secure it to the board. Whether you need an easel or not depends on how you end up working. Some artists work so ‘wet’ they need to use a flat surface to work on with the ability to raise one side to cause the medium to flow; this is a long way from the classic image of an old master with the canvas on an easel.

Ensure you have some cheap cartridge paper you can experiment with, so you don’t get frozen by the thought that ‘this board is so expensive I better make this one a masterpiece!’. 

It can also help to have a range of sizes, so try doing small watercolour pieces, before migrating to larger formats. It is quicker to get a result and also takes the pressure off you.

Whereas for charcoal, you generally need to work on a bigger piece of paper straight away; but a relatively low cost large format ring-bound sketch book (around A3 size) is fine for this purpose.

Mixed media

In truth, many painting use mixed media, although some more obviously than others.

For example, a watercolour may use a number of other media:

    • pens to resolve some features (but best used sparingly), such as railings;
    • inks to help develop greater tonal depth;
    • gouache to finish a piece with greater colour intensity, for flicking effects or for white highlights;
    • pastels to help develop a light glaze of texture – for foliage or other features – as a finish.

There are also numerous special materials that can be tried, such as liquid pencil, to create effects.

But there is no obligation to throw everything at a painting, and it can be easy to get carried away with mixing media.

A great artist like Kurt Jackson has developed his own brilliant style – a vocabulary that is special to him – and his use of mixed media feels unforced and natural.

It is always best to start simple and work on adding ingredients over time, as and when they come naturally to you, rather than merely including them to try to emulate Kurt.


These fundamentals are the things I have internalised from an intensive three years of learning to become an artist, with the help principally of my mentor Alison Vickery, but also some other helpers along the way.

In the following essays, I want to show how these fundamental are reflected in sketches, studies and a few developed pieces I will share, from my endeavours.

I often forget these principles, catching myself in an act of regression, and then have to remind myself. Alison’s voice is often in my head …

‘paint what interests you’

‘don’t get too fiddly’

‘work the whole area’

‘stop right there!’

‘put down the pencil’

‘is the tonal range ok?’

‘loosen up’

I call them “Alison’s Aphorisms”.

It takes years to internalise the fundamentals of being an artist, and even then, so easy to get carried away and still fall flat on one’s face.

Equally, as time goes by nice surprises happen. 

You find that you ‘accidentally’ created something quite good, and you scratch your head and ask ‘How did I manage that?’. 

Don’t be surprised, you are becoming an artist!

Gradually, the better stuff happens more frequently and the not so great become less frequent. The art folder gets fatter and the dustbin less full of discarded pieces.

But everything you do provides a learning moment. Keep some of the not so great paintings to remind yourself of how far you have travelled.

Keep asking questions; it worked for me when I was a scientist and as a consultant, and it is something I continue to do as an artist.

Keep experimenting, and keep asking questions.

Making mistakes is fine, because that is the only way to learn.


(c) Richard W. Erskine, 2020

Next essay in this series will be Becoming an artist: sketchbooks

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Becoming an artist: awakenings

This is about my journey. Everyone’s journey will be different. I am addressing those, who like me, have spent a long time thinking about doing art, but never finding the time or courage to do it.

How many people suffer from that debilitating idea “I can’t paint*”. This is often because someone told you so, or gave your confidence such a knock, you never quite recovered enough to try again [* paint, or anything else you would like to do – learn to play an instrument, be a sculptor, do maths, play the drums, or whatever].

Schoolchildren are expected to make a choice quite early in life as to what they want to be. At face value it seems reasonable to expect a student to start to specialise at some point, but the mirror image of this is that they must ‘drop’ a whole load of stuff that is valuable in life. Little wonder that in older age people often pick up on subjects they loved but did not have an opportunity to develop when young.

I chose to specialise in science, even before I was forced to make that choice. 

I’d happily freeze to death looking at the moon and stars through a small but much loved telescope, clutching my Observer’s Book of Astronomy (I think I may have had a 1st edition from 1962, when I was just 9). Geometry was my favourite subject. 

A little later but still quite young I had a laboratory, and loved to do experiments with bits of apparatus such as a Liebig Condensor, regularly causing a stink that required all the windows in the house to be opened to clear the smell.

I was never a rote learner. I always asked questions and challenged my teachers. I love the ability of small children to ask “why?” then why again, to never be afraid to ask questions. But it is also important to learn how to listen to the answers, to reflect on them and then to do work to explore things more deeply. This gives rise to more questions.

I wanted to understand the world and how it was put together, and went on to study Chemistry at university. To highlight my tendency to question things, there is a story from my final exams I want to share. 

There was a question about chemical bonding I didn’t like because of the way it was framed, so I answered it just like I knew the examiner would want it answered, but then wrote “However, I want to challenge the framing of this question, and believe the question ought to have been …”. 

I then wrote a second answer to my newly framed version of the question. The external examiner (Prof. S F A Kettle, I believe) was so impressed he told my mentor that he would have happily awarded me an upper first if such a thing existed. Nevertheless, I was very proud of the 1st Class Honours degree I did receive.

I stayed in academia for a while, doing a PhD at Cambridge and then a postdoc in Bristol, where I met Marilyn, who was to become my wife. 

For a range of reasons, I decided to leave academia in 1982, and worked in computer-aided design for several years, but for the final 30 years of my career up to 2016 I was an information management consultant, helping large organisation to be better at breaking down the information silos in their organisations, and be better custodians of their knowledge.

I enjoyed using creative ways to discuss and articulate problems. I never stopped asking questions. Clients liked my thoughtful approach, and the fact I didn’t try to ram software products down their throats (as had been their experience on the previous times somebody had promised to fix their issues).  In ways that I now recognise only in retrospect, my scientific and artistic sides both found expression in the way I did consultancy.

Throughout this time, I was always questioning myself, always learning from new engagements about other ways to look at things. Even when one thinks one has mastered a skill, there will always be opportunities to explore nuances or discover new variants of a skill.

Over my 63 years before I retired I had tried on a few occasions to learn to paint. Even at school there was a group of us scientists who showed artistic promise and the art teacher allowed us access to the studio to paint just for fun, not for any examination. And I have attended classes on watercolours 30 years ago, but it never went anywhere.

Meanwhile, one of the favourite activities that Marilyn and I enjoyed over these years was visiting art exhibitions, and we have numerous catalogues to testify to this. I was great at looking at art, but not doing it.

There could have been many reasons for the failure of my early attempts to develop further. 

I had a time-consuming and at times stressful job, involving a lot of travel abroad. Marilyn and I brought up two girls, and there were always too many projects (that, funnily enough, seems not to have changed!). In Bristol I was an early recruit to Scientists Against Nuclear Arms (SANA), and became its Secretary for a while. Writing and speaking took up a lot of my extra curricula head space (SANA later became SGR, Scientists for Global Responsibility, and is still active).

Since my retirement, I have become very active on climate change, giving talks and helping to found a group, Nailsworth Climate Action Network in my home town, which I am currently Secretary of.

Despite being busy with family – now with grandchildren – and home, garden, climate change, etc. I decided I wanted to have another go at learning to paint. 

Marilyn and I have for several years tried to stop buying stuff – we have too much already – and instead buy vouchers for experiences or classes. 

About 6 years ago she bought me a voucher for a set of 1-to-1 art lessons from our dear friend Di Aungier-Rose. Unlike previous art teachers I had tried, Di was very good at getting me to loosen up and not stress about what I was doing; to not obsess about colour and so on. To just have fun, and see what emerged. She imparted little nuggets of wisdom here and there, but without overloading me.  

This unlocked the first door to me becoming an artist, and gave me a boost in confidence. I knew from that point on that I had an innate ability to become an artist, even while I knew it would be a long journey.

However, the ‘3 steps forward, 2 steps back’ rule seemed to hit me. I got waylaid by climate change, sorting out my pension for retirement, etc. There is always a long list of things stopping us doing what we want!

Also, I was really hankering after learning how to use watercolours, and had a lot of admiration for the work of another local artist, Alison Vickery. So, a few years ago Marilyn bought me another present: to attend a batch of classes at Alison’s weekly art class, held at Pegasus Art in Stroud.

I will talk more about what Alison has taught me in later essays in this series, but the key point here was that I started to carve out a time during the week – every week – when I wouldn’t be distracted by the other things crowding in on me. Wednesday afternoon was to be art time. So even if I didn’t manage to do any art during the rest of the week, this time was sacrosanct.

I have kept attending these classes ever since.

Maybe that is the secret – and of course a lot easier when you are retired – to find a space to do your art. 

If you are very disciplined and no longer require a mentor, then it is perfectly possible to create this time and space for yourself. It may mean creating a Woman Shed or Man Shed in the garden, to get away from domestic distractions.

However it is done, you need to find your time, and your space.

You need to unlearn the “I can’t do X” gremlin in your brain.

Now it is time to loosen up; to experiment; to ask questions; and to rediscover the joy of learning something new.

(c) Richard W. Erskine, 2020

Next essay in this series will be Becoming an artist: fundamentals

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Keep Calm, But Take Action

How do people respond to ‘signals’ regarding their health and well-being? 

Some people will refuse to respond, such as these smokers I saw outside a hospital a few days ago (where I was visiting my daughter, thankfully now discharged after a nasty infection; not coronavirus).

Screenshot 2020-03-13 at 07.27.24

There is a large sign ‘Strictly No Smoking’, that is routinely ignored.

And what of people who read Richard Littlejohn and others, for years in the Daily Mail, Daily Telegraph, The Spectator, etc., railing against the ‘nanny state’ or ‘elf and safety’ ?

Large swathes of people are effectively inoculated against alarm, and will not respond to signals, even if a megaphone was put to their ear. 

These are the super-spreaders of denial and complacency. 

I am not talking here of professional dissemblers in the climate realm who make their living trying to undermine the scientific consensus. Those who write opinion pieces claiming, wrongly:

  • more CO2 is good for us because plants will flourish (Matt Ridley);
  • or claiming ocean acidification is non-existent (James Delingpole);
  • or that it’s the sun’s fault (Piers Corbyn);
  • or that we are about to enter an ice age (Daily Mail and Daily Telegraph every 6 months for the last 10 years) .

Like stories of Lord Lucan sightings, these lazy opinion formers simply dust off the old rubbish to serve it up again, and again. Year in year out. It pays the mortgage I suppose. And when they tell people what they want to hear – that we can carry on regardless – there is no shortage of chortling readers. Ha ha ha. How very funny, poking fun at the experts.

No, I am  not talking about these dissemblers, but rather, the mass of those who have been reading this rubbish for 30 years and are now impervious to evidence and scornful of experts.

And there is an epidemic of such people, who believe

no need to be alarmed, staying calm and carrying on regardless 

It is not just health or climate change, but is applied universally. For example, the  Millennium Bug was apparently overblown according to these people (having seen the code that needed fixing, I can assure you, it wasn’t).

However, those who deal with addressing threats are in a no-win situation: if they act and prevent the worst happening, then people – who are largely unaware of what is being done behind the scenes – will say ‘you see, it wasn’t a problem’.  If they didn’t act, then guess who would get the blame.

Yet when people do raise the alarm, such as when parents wrote letters complaining of the risks of the vast colliery tip adjacent to the Welsh town of Aberfan, they are often brushed off, and the result was a disaster that lives on in our memory (see Note).

Now we have the Covid-19 virus. 

It is no surprise that there have been many saying that people are being unnecessarily alarmed; and the message is the same – we should ‘Keep Calm and Carry On’.

It’s just like seasonal flu, don’t worry. It will disappear soon enough.

These are often the same people who rail against ‘climate alarmism’.

Man-made global heating will be orders of magnitude worse than Covid-19, across every aspect of society – food security, sea-level rise, eco-system collapse, mass migration, heat stress, etc. – and over a longer timescale but with increasing frequency of episodic shocks, of increasing intensity.

Unlike Covid-19, there will be no herd immunity to climate change.

But we have the ability to halt its worst impacts, if we act with urgency.

We cannot quarantine the super-spreaders of denial and complacency, but we can confront them and reject their message.

I wonder, as the mood seems to be changing, and experts are now back in fashion it seems, could this be a turning point for action on climate change?

Can we all now listen to the experts on climate change?

Can we Keep Calm, but Take Action?

(c) Richard W. Erskine, 2020



There was a collapse of part of the massive colliery spoil tip at 0915 on 21st October 1966  The main building hit was Pantglas Junior School, where lessons had just begun. Five teachers and 109 children were killed in the school.

As one example of numerous correspondence prior to this, raising concerns, was a petition from parents of children at The Grove school raising the issue of flooding undermining the tip. This was passed up through the bureaucracy, but a combination of the Borough Council and National Coal Board failed to act. As the official report noted in unusually strong words:

“As we shall hereafter see to make clear, our strong and unanimous view is that the Aberfan disaster could and should have been prevented. … the Report which follows tells not of wickedness but of ignorance, ineptitude and a failure in communications. Ignorance on the part of those charged at all levels with the siting, control and daily management of tips; bungling ineptitude on the part of those who had the duty of supervising and directing them; and failure on the part of those having knowledge of the factors which affect tip safety to communicate that knowledge and to see that it was applied” (bullet 18., page 13)

1966-67 (553) Report of the tribunal appointed to inquire into the disaster at Aberfan on October 21st, 1966

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Thoughts on starting a community climate action group (a talk)

Good evening.

Professor Katharine Hayhoe, a leading climate scientist, and hugely influential communicator, is often asked:

What is the first thing I should do about climate change?

Her answer is simple:

Talk about it!

How on Earth can that reduce our carbon footprint you may ask?

On the other hand, it is a common phenomenon when climate groups start, that the first thought is often ‘we need to build a solar PV array on the edge of town’. 

I am not saying don’t do that, but there are big benefits to talking about it, and not rushing to build.

  • Firstly, if people are not fully on board with the idea that urgent action is needed to address global warming, then some talking will really help change hearts and minds.
  • Secondly, there are many different ways we can reduce our carbon footprint, and we need to push forward on all fronts. Don’t let the enthusiasm for one project crowd out ideas for other things that need to be discussed, and weighed up.
  • Thirdly, if we focus solely on technological solutions like electric cars, we potentially exclude a lot of people who are put off by technology, or cannot afford to invest in them; and would like a reliable bus service to be a priority! 
      • We need to build a much bigger tent where we discuss topics like consumption, waste, heating, public transport, energy efficiency and local food. Topics that will draw in as wide a population as possible.
  • Finally, by developing a wide perspective on all different approaches and potential initiatives, the group will be in a better position to call on community support for emerging projects.

Some will argue: but why is the challenge of addressing dangerous global warming being placed on the shoulders of householders and local communities? 

Surely, Government and big business have the resources and power to make it happen?

I reject the implied binary thinking here.

In fact, Government, big business, pension funds, County Councils, District Councils, Parish Councils, local businesses, householders – you and me – can all make a difference and influence what happens.

Ok, so there are some things that only Governments and big business can do. But ultimately, every product and service is – directly or indirectly – created for us. 

We have agency – we can decide: 

  • what we do, 
  • how we do it.
  • and how often we do it.

We can choose to car share twice a week; or opt for that staycation; or reduce our meat consumption. Every family is different, but we make lots of choices, intentionally or not; and every choice matters.

We started NailsworthCAN in 2016 around the time of the Paris Agreement. Our focus was always on practical action rather than protest. But action comes in many forms: engaging, influencing, networking, capacity building, constructing.

We have spent a lot of time developing the conversation with different groups in the community: with the Town Council, Church, Schools, Rotary, Transition Stroud, etc., and with our previous and current MP.  We act sometimes to lead, sometime to act as a catalyst, and sometimes simply to provide support to others. Hence the use of the word ‘network’.

We have run stalls, organised talks on diverse topics, and identified a range of projects. We created and distributed a Carbon Pledges sheet. We have met and talked with hundreds of local people, and we have recruited members with a fantastic range of skills and knowledge.

We have ran workshops to gather ideas on local projects that people are interested in across a range of topics –

  • Food and agriculture;
  • Mobility and transport;
  • Buildings and their environment;
  • Energy generation;
  • Waste;
  • Nature and the Environment;
  • Health and Wellbeing.

We have worked with the Town Council to help develop an outline plan across these areas.

One specific initiative is to conduct a survey of hospitality venues in town to assess current practice on energy use, waste, etc., and identify ‘wins’ for these venues, the town and the planet.

Another initiative is to develop a 5-year tree planting plan on council land.

And another is a community-led domestic retrofit scheme.

And yes, we have a few renewable energy generation schemes in the pipeline.

Each of the climate groups I have met has its own personality, way of organising, and methods for coordinating their efforts with their respective Parish councils.

Each has had ideas on how to push forward on different fronts, and all can learn from each other.

The great evolutionary biologist E. O. Wilson – when being interviewed on BBC Radio 4’s ‘The Life Scientific’ said:

“Humanity has Palaeolithic emotions, medieval institutions and god-like power, … and that is a dangerous combination”.

But I would respond by saying we also have the capacity to overcome our destructive power, and work collectively to reveal the positive side of our humanity.

Don’t be critical if you start with talking, then move to small actions.

Just don’t stop at small actions.

Small actions can provide learnings and help us move to larger ones.

Share and celebrate success, as we do on social and printed media. 

Small conversations can be the foundation for bigger ones, resulting in significant actions, and system change.  Ultimately, this is all about system change; business as usual  will not get us to where we need to be.

Remember, it is a marathon not a sprint, and like a marathon, we need to help each other stay the course.

I wish Minchinhampton every success as it starts its conversation.

Thank you.

…. o o O o o ….

Richard W. Erskine, Secretary of NailsworthCAN

Invited talk at the launch of Minchinhampton Climate Action Network.

11th March 2020.


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The Curious Case of Heat Pumps in the UK

Heat Pumps, whether Air-Sourced or Ground-Sourced, can and should be making a major contribution to decarbonising heating in the UK. Heating (both space heating and water heating) is major contributor to our carbon footprint.

Heat pumps are now incredibly efficient – for 1 unit of electrical energy you put in you can get at least 3 units back in the form of heat energy (a pump compresses the air and this causes it to rise in temperature; two century old physics at work here).  The process works sufficiently well even in UK winters.

The pumps are now relatively quiet (think microwave level of noise). They can deliver good payback (even more so if there was a cost on carbon). They even work with older properties (countering another one of the many myths surrounding heat pumps).

I even heard Paul Lewis on BBC’s ‘Money Box’ (Radio 4) – clearly getting confused between heat pumps and geothermal energy – saying ‘oh, but you need to be in a certain part of the country to use them’ (or words to that effect).

We clearly need much more education out there to raise awareness of the potential of heat pumps.

When combined with solar (to provide some of the electricity), they are even better.

So why is the take-up of heat pumps still too slow? Why is the Government not pushing them like crazy (it is an emergency, right!)? Why are households, when replacing old boilers, till opting for gas?

When we had the AIDS crisis in the 1980s, the UK Government undertook a major health awareness campaign, and other countries also, which largely succeeded. In an emergency, Governments tend to act in a way that ‘signals’ it is an emergency.

The UK Government is sending no such signals. Bland assurances that the commitment to reach net zero by 2050 is not a substitute for actions. In the arena of heat, where is the massive programme to up-skill plumbers and others? Where is the eduation programme to demystify heat pumps and promote their adoptions?

And where is the joined up thinking?

This article below from Yorkshire Energy Systems, based on their extensive research and practical experience, suggests one reason – that EPCs (Energy Performance Certificates) issued for homes and including recommended solutions – are biased against heat pumps.

The mismatch between what the Government is saying (that heat pumps are part of the decarbonisation solution) and what EPCs are advising suggests a clear lack of joined up thinking.

… and no sign that the Government really believes that urgent action is required.

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Increasing Engineering Complexity and the Role of Software

Two recent stories from the world of ‘big’ engineering got me thinking: the massive delays in the Crossrail Project and the fatal errors in the Boeing 737 Max, both of which seem to have been blighted by issues related to software.

Crossrail, prior to the announcement of delays and overspend, was being lauded as an example of an exemplar on-time, on-budget complex project; a real feather in the cap for British engineering. There were documentaries celebrating the amazing care with which the tunnelling was done to avoid damage at the surface, using precise monitoring and accurately positioned webs of hydraulic grouting to stabilise the ground beneath buildings. Even big data was used to help interpret signals received from a 3D array of monitoring stations, to help to actively manage operations during tunnelling and construction. A truly awesome example of advanced engineering, on an epic scale.

The post-mortem has not yet been done on why the delays came so suddenly upon the project, although the finger is being pointed not at the physical construction, but the digital one. To operate the rail service there must be advanced control systems in place, and to ensure these operate safely, a huge number of tests need to be carried out ‘virtually’ in the first instance, to ensure safety is not compromised.

Software is something that the senior management of traditional engineering companies are uncomfortable with; in the old days you could hit a machine with a hammer, but not a virtual machine. They knew intuitively if someone told them nonsense within their chosen engineering discipline; for example, if a junior engineer planned to pour 1000 cubic metres of cement into a hole and believed it would be set in the morning. But if told that testing of a software sub-system will take 15 days, they wouldn’t have a clue as to whether this was realistic or not; they might even ask “can we push to get this done in 10 days?”.

In the world of software, when budgets and timelines press, the most dangerous word used in projects is ‘hope’. “We hope to be finished by the end of the month”; “we hope to have that bug fixed soon”; and so on  Testing is often the first victim of pressurised plans. Junior staff say “we hope to finish”, but by the time the message rises up through the management hierarchy to Board level, there is a confident “we will be finished” inserted into the Powerpoint. Anyone asking tough questions might be seen as slowing the project down when progress needs to be demonstrated.

You can blame the poor (software) engineer, but the real fault lies with the incurious senior management who seem to request an answer they want, rather than try to understand the reality on the ground.

The investigations of the Boeing 737 Max tragedy are also unresolved, but of course, everyone is focusing on the narrow question of the technical design issue related to a critical new feature. There is a much bigger issue at work here.

Arguably, Airbus has pursued the ‘fly by wire’ approach much earlier than Boeing, whose culture has tended to resist over automation of the piloting. Active controls to overcome adverse events has now become part of the design of many modern aircraft, but the issue with the Boeing 737 Max seems to have been that this came along without much in the way of training; and the interaction between the automated controls and the human controls is at the heart of the problem. Was there also a lack of realistic human-centric testing to assess the safety of the combined automated/ human control systems? We will no doubt learn this in due course.

Electronics is of course not new to aerospace industries, but programmable software has grown in importance and increasingly it seems that the issue of growing complexity and how to handle the consequent growth in testing complexity, has perhaps overtaken the abilities of traditional engineering management systems. This is extending to almost every product or project – small and large – as the internet of everything emerges.

This takes me to a scribbled diagram I found in an old notebook – made on a train back in 2014, travelling to London, while I debated the issue of product complexity with a project director for a major engineering project. I have turned this into the Figure below.

Screenshot 2019-08-14 at 19.30.09

There are two aspects of complexity identified for products: 

  • Firstly, the ‘design complexity’, which can be thought of as the number of components making up the product, but also the configurability and connectivity of those components. If printed on paper, you can thinking of how high the pile of paper would be that identified every component, with a description of their configuration and connection. This would apply to physical aspects but also software too; and all the implied test cases. There is a rapid escalation in complexity as we move from car to airliner to military platform.
  • Secondly, the ‘production automation complexity’, which represents the level of automation involved in delivering the required products. Cars as they have become, are seen as having the highest level of production automation complexity. 

You can order a specific build of car, with desired ‘extras’, and colour, and then later see it travelling down the assembly line with over 50% of the tasks completely automated; the resulting product with potentially a nearly unique selection of options chosen by you. It is at the pinnacle of production automation complexity but it also has a significant level of design complexity, albeit well short of others shown in the figure. 

Whereas an aircraft carrier will in each case be collectively significantly different from any other in existence (even when originally conceived as a copy of an existing model) – with changes being made even during its construction – so does not score so high on ‘production automation complexity’. But in terms of ‘design complexity’ it is extremely high (there are only about 20 aircraft carriers in operation globally and half of these are in the US Navy, which perhaps underlines this point).

As we add more software and greater automation, the complexity grows, and arguably, the physical frame of the product is the least complex part of the design or production process. 

I wonder is there a gap between the actual complexity of the final products and an engineering culture that is still heavily weighted towards the physical elements – bonnet of a car, hull of a ship, turbine of a jet engine – and is this gap widening as the software elements grow in scope and ambition? 

Government Ministers, like senior managers, will be happy being photographed next to the wing of a new model of airliner – and talk earnestly about workers riveting steel – but what may be more pivotal to success is some software sub-system buried deep in millions of lines of ‘code’; no photo opportunities here.

Screenshot 2019-08-14 at 19.30.27

As we move from traditional linear ‘deterministic’ programming to non-deterministic algorithms – other questions arise about the increasing role of software. 

Given incomplete, ambiguous or contradictory inputs the software must make a choice about how to act in real time. It may have to take a virtual vote between independently written algorithms. It cannot necessarily rely on supplementary data from external sources (“no, you are definitely nose diving not stalling!”), for system security reasons if not external data bandwidth reasons.

And so we continue to add further responsibility, onto the shoulders of the non-physical elements of the system.

Are Crossrail and the 737 Max representative of a widening gap, reflected in an inability of existing management structures to manage the complexity and associated risks of the software embedded in complex engineering products and projects? 

© Richard W. Erskine, 2019

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Boris loves Corbyn

No not Jeremy; his brother.

For some years now Boris Johnson has channelled the crank theories of Piers Corbyn, who appeared in the 2007 film The Great Global Warming Swindle, which was shown to be ill-founded.

Rather like the myth that carrots helped RAF pilots see at night during WWII  which was such a great story that even today it is repeated and believed, the idea that some changes in the Sun’s output is responsible for recent climate change is a similarly attractive myth, which keeps on being repeated.

The BBC had to apologise for Quentin Letts’ execrable hatched job on the Met Office in 2015, which also included Piers Corbyn. 

The truth is that we know with a confidence unsurpassed in many fields of science what is causing global warming; it’s not the sun, it’s not volcanoes; it’s not contrails. The IPCC’s 5th Assessment Report (2013) was clear that greenhouse gases (principally carbon dioxide) resulting from human activities are the overwhelming driver of global warming (see Figure 8.15)

So you might expect Boris Johnson as a leading politician, to reference the IPCC (Intergovernmental Panel on Climate Change), which gathers, analyses and synthesises the published work of thousands of scientists with relevant expertise on behalf of the nations of the world.

Instead, he has referred to the “great physicist and meteorologist Piers Corbyn” (It’s snowing, and it really feels like the start of a mini ice age, Boris Johnson, Daily Telegraph, 20th January 2013). Piers Corbyn has no expertise in climate science and theories like his have been completely debunked in a paper published in the Proceedings of The Royal Society:

… the long-term changes in solar outputs, which have been postulated as drivers of climate change, have been in the direction opposite to that required to explain, or even contribute to, the observed rise in Earth’s global mean air surface temperature (GMAST) …

What is alarming is that in the face of this strong scientific evidence, some Internet sources with otherwise good reputations for accurate reporting can still give credence to ideas that are of no scientific merit. These are then readily relayed by other irresponsible parts of the media, and the public gain a fully incorrect impression of the status of the scientific debate.

“Solar change and climate: an update in the light of the current exceptional solar minimum”, Proceedings of The Royal Society A, Mike Lockwood, 2nd December 2009

So, for Boris Johnson to call himself an “empiricist” is, frankly, laughable.

He has also cozied up to neoliberal ‘think tanks’ implacably opposed to action on global warming. 

I think we can safely say that hitherto he has firmly placed himself in the DENIAL bucket (in the illustration below).

Screenshot 2019-07-29 at 21.24.30

He shares this perspective with other hard Brexiteers in the new Cabinet, who are itching to deregulate the UK economy, such as Jacob Rees-Mogg, and see action on global warming as a constraint on unregulated markets.

In his acceptance speech on becoming Prime Minister, Boris Johnson never mentioned climate change. But since then he has reiterated Theresa May’s Government’s commitment to net zero by 2050, and

Responding to concerns expressed by Shadow Treasury Minister Anneliese Dodds that he had not focused sufficiently climate change in the initial statements outlining his priorities as Prime Minister, Johnson replied: “The House will know that we place the climate change agenda at the absolute core of what we are doing.”

(edie, 29th July 2019)

He went on to say

He said: “This party believes in the private sector-generated technology which will make that target attainable and deliver hundreds of thousands of jobs. That is the approach we should follow.” …

Predicting that the UK will “no longer” be contributing to climate change by 2050, Johnson said: “We will have led the world in delivering that net-zero target. We will be the home of electric vehicles—cars and even planes—powered by British-made battery technology, which is being developed right here, right now.”

(edie, 29th July 2019)

By imagining that industry alone (without any stated plans for an escalating tax on carbon), can somehow address the huge transformation required, on the timescale required, without concerted effort at every level of Government (top down and bottom up), and civil society, he remains disconnected from reality, let alone science.

Moving from DENIAL to COMPLACENCY is an advance for Boris – assuming for the moment this is not another flip-flopping of positions that he is famed for – but it is hardly the sign of the climate leadership required. We need a leadership that respects the science, and understands the policy implications and prescriptions required.

Did anyone in the house ask the Prime Minister if he accepts and will fully support the recommendation of the Climate Change Committee’s report Net Zero – The UK’s contribution to stopping global warming? 

They need to, because great words need to turned into a plan of action, and every year we delay will make the transition more painful (it is already going to be painful enough, but they are not telling you that, are they?).

That will not be enough to meet the public’s concerns over the climate emergency, and increasingly, the public will be expecting leadership that has moved from COMPLACENCY to the URGENCY position.

Many see GREEN RADICALISM as now an unavoidable response to the COMPLACENCY in Whitehall.

If Boris Johnson fails to jettison his neoliberal friends and the crank science that is part of their tool-kit – who are trying (and have succeeded so far) in putting the breaks on meaningful and urgent action – the longer term political fall-out will make Brexit look like a tea party.

(c) Richard W. Erskine,, July 2019


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The Climate Change Committee just failed to invent a time machine

These past two weeks have been such a momentous time for climate change in the UK it is hard to take in. My takes:

On 21st April, Polly Higgins, the lawyer who has spent a decade working towards establishing ecocide as a crime under international law, sadly died. At a meeting at Hawkwood Centre, Stroud, I heard the inspiring Gail Bradbrook speak of how Polly had given her strength in the formation of Extinction Rebellion. 

On 23rd April, Greta Thunberg spoke to British Parliamentarians with a clear message that “you did not act in time’, but with imagination and some ‘Cathedral thinking’ it is not too late to act (full text of speech here).

On 30th April, Extinction Rebellion met with the Environment Secretary Michael Gove, a small step but one that reflects the pressure that their actions (widely supported in the country) are having. Clare Farrell said the meeting “.. was less shit than I thought it would be, but only mildly”, but it’s a start.

On 1st May, the UK’s Parliament has declared a climate emergency

On 2nd May the Committee on Climate Change (CCC), setup under the 2008 Climate Change Act, has published its report “Net Zero – The UK’s contribution to stopping global warming” to the Government on how to reach net zero by 2050.

These are turbulent times. Emotions are stirring. Expectations are high. There is hope, but also fear.

The debate is now raging amongst advocates for climate action about whether the CCC’s report is adequate.

Let’s step back a moment.

The IPCC introduced the idea of a ‘carbon budget’ and this is typically expressed in the form such as (see Note):

“we have an X% chance of avoiding a global mean surface temperature rise of  Y degrees centigrade if our emissions pathway keeps carbon emissions below Z billion tonnes”

The IPCC Special 1.5C Report, looked at how soon we might get to 1.5C and the impacts of this compared to 2C. As Carbon Brief summarised it:

At current rates, human-caused warming is adding around 0.2C to global average temperatures every decade. This is the result of both “past and ongoing emissions”, the report notes.

If this rate continues, the report projects that global average warming “is likely to reach 1.5C between 2030 and 2052”

Perhaps the most shocking and surprising aspect of this report was the difference in impacts between 1.5C and the hitherto international goal of 2C. The New York Times provided the most compelling, graphic summary of the change in impacts. Here are a few examples:

The percentage of the world’s population exposed to extreme heat jumps from 14% to 37%

Loss of insect species jumps from 6% to 18%

Coral reefs suffer “very frequent mass mortalities” in a 1.5C world, but “mostly disappear” in a 2C world.

So, in short, 1.5C is definitely worth fighting for.

In view of the potential to avoid losses, it is not unreasonable for Extinction Rebellion and others to frame this as a “we’ve got 12 years”. The IPCC says it could be as early as 12 years, but it might be as late as 34 years. What would the Precautionary Principle say? 

Well, 12 years of course.

But the time needed to move from our current worldwide emissions to net zero is a steep cliff. You’ve all seen the graph.


It seems impossibly steep. It was a difficult but relatively gentle incline if we’d started 30 years ago. Even starting in 2000 was not so bad. Every year since the descent has  become steeper. It is now a precipice.

It is not unreasonable to suggest it is impossibly steep.

It is not unreasonable to suggest we blew it; we messed up.

We have a near impossible task to prevent 1.5C.

I’m angry about this. You should be too.

I am not angry with some scientists or some committee for telling me so. That’s like being angry with a doctor who says you need to lose weight. Who is to blame: the messenger? Maybe I should have listened when they told me 10 years back.

So if the CCC has come to the view that the UK at least can get to net zero by 2050 that is an advance – the original goal in the Act was an 80% reduction by 2050 and they are saying we can do better, we can make it a 100% reduction.

Is it adequate?

Well, how can it ever be adequate in the fundamental sense of preventing human induced impacts from its carbon emissions? They are already with us. Some thresholds are already crossed. Some locked in additional warming is unavoidable.

Odds on, we will lose the Great Barrier Reef.  Let’s not put that burden on a committe to do the immpossible. We are all to blame for creating the precipice.

That makes me sad, furious, mournful, terrified, angry.

There is a saying that the best time to have started serious efforts to decarbonise the economy was 30 years ago, but the next best time is today.

Unfortunately, the CCC does not have access to a time machine.

Everyone is angry.

Some are angry at the CCC for not guaranteeing we stay below 1.5C, or even making it the central goal. 

Extinction Rebellion tweeted:

The advice of @theCCCuk to the UK government is a betrayal of current & future generations made all the more shocking coming just hours after UK MPs passed a motion to declare an environment & climate emergency. 

It is I think the target of 2050 that has angered activists. It should be remembered that 2050 was baked into the Climate Change Act (2008). It should be no surprise it features in the CCC’s latest report. The CCC is a statutory body. If we don’t like their terms of reference then it’s easy: we vote in a Government that will revise the 2008 Act. We haven’t yet achieved that.

Professor Julia Steinberger is no delayist (quite the opposite, she’s as radical as they come), and she has tweeted back as follows:

Ok, everyone, enough. I do need to get some work done around here.

(1) stop pretending you’ve read & digested the whole CCC net-zero report. It’s 277 pretty dense pages long. 

(2) there is a lot of good stuff & hard work  making the numbers work there.  

3) Figuring out what it means for various sectors, work, finance, education, training, our daily lives & cities & local authorities and so on is going to take some thinking through.

(4) If you want a faster target, fine! I do too! Can you do it without being horrid to the authors and researchers who’ve worked like maniacs to try to get this much figured out? THEY WANT TO BE ON YOUR SIDE! 

(5) So read it, share it, reflect on it, and try to figure out what & how we can do a lot faster, and what & how we can accelerate the slower stuff.

Treat the CCC report as in reality an ambitious plan – it really is – in the face of the precipice, but also believe we can do better.

These two ideas are not mutually exclusive.

Maybe we do not believe that people can make the consumption changes that will make it possible to be more ambitious; goals that politicians might struggle to deliver.

Yet communities might decide – to hell with it – we can do this. Yes we can, do better.

Some are scornful at Extension Rebellion for asking the impossible, but they are right to press for better. However, can we stop the in-fighting, which has undermined many important fights against dark forces in the past. Let’s not make that mistake again.

Can we all be a little more forgiving of each other, faced with our terrible situation.

We are between a rock and a hard place.

We should study the CCC report. Take it to our climate meetings in our towns, and halls, and discuss it. 

How can we help deliver this?

How can we do even better?

I for one will be taking the CCC report to the next meeting of the climate action group I help run.

I’m still mournful.

I’m still angry.

But I am also a problem solver who wants to make a difference.

Good work CCC.

Good work XR.

We are all in this together.

… and we don’t have a time machine, so we look forward.

Let not the best be the enemy of the good.

Let not the good be a reason for not striving for better, even while the best is a ship that has long sailed.

© Richard W. Erskine, 2019



You pick an X and Y, and the IPCC will tell how much we can emit (Z). The ‘X%’ is translated into precisely defined usages of terms such as ‘unlikely’, ‘likely’, ‘very likely’, etc. To say something is ‘likely‘ the IPCC means it has a greater than 66% chance of happening.

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