Category Archives: Science

Do Tipping Points mean Runaway Global Warming after 12 years?

Is it 12 years?

That’s a belief I am finding increasingly common, but it really isn’t what the science is telling us.

The science is saying that things are very serious and every year we fail to “bend the curve down” as Greta Thunberg puts it, the worse the outcomes. We know from the IPCC (Intergovernmental Panel on Climate Change) 1.5oC Special Report that 2oC is significantly, perhaps surprisingly, worse than 1.5oC.

That is not a reason for a dystopian view that all is lost if we fail to get to zero after 12 (or is it now 11 years) if we don’t get to net zero by then.

The science is not that certain. The IPCC said that 2030 global net emissions must reduce by 45% versus 2010 emissions to achieve 1.5oC, and get to zero by 2050.

That is not to say we should not have highly ambitious targets, because the sooner we peak the atmospheric concentration of CO2 in the atmosphere, the sooner we peak the global warming (see Note 1).

Because it is such a huge challenge to decarbonise every sector of our economies, we should have started 30 years ago, and now we have to move very fast; whatever date you put on it. So, if I question some of the dystopian memes out there it is certainly not to question the need for urgent action.

Feedbacks and Tipping Points

I think what lies at the root of the dystopian message is a belief that tipping points – and there are quite a number in the Earth system – are like dominoes, and if one goes over, then all the rest follow. At a meeting I went to that included policy experts, XR, scientists, and others, I got into a chat about feedbacks and tipping points.

The person I spoke to was basically 100% convinced that if we did not get to net zero after ’12 years’ we would set off feedbacks and tipping points. It really would be game over. I want to summarise my side of the conversation:

I appreciate your concern about tipping points; they are real and need to be taken into account.

It is complicated and there are cases that can runaway (take Venus), but there is often a response that limits a particular feedback.

For example, extra CO2 causes warming, which due to the Clausius–Clapeyron relation means that additional water vapour (gaseous form of water, not clouds) is added to the atmosphere (7% extra for every 1C of warming). Since H2O is also a strong greenhouse gas that causes more warming.

This is a crucial ‘fast feedback’ included in climate models. It means that the expected 3oC of warming from doubling CO2 in the atmosphere is actually 1oC from the CO2 and 2oC extra from the H2O feedback (see Note 2).

Ok, so why doesn’t this warming carry on as a runaway (there is plenty of water in the ocean)?

The reason is Stefan’s Law (or ‘Planck Response’).

A body at temperature T emits energy at a rate proportional to T to the power 4. So the loss of heat accelerates and this at some points stops the feedback process (see Note 3).

A way to think about this is a plastic container with a hole at the bottom (say 7mm wide). Pour water from a tap at a constant rate, say half a litre per minute, into the container. What happens? The water level in the container rises to a point that maintains this level. At this point the pressure at the base of the container has increased to the point that the rate of flow of water out of the bottom is equal to the rate of flow in. They are in balance, or ‘equilibrium’.

If I now plug the 7mm hole and drill a 6mm one instead (yes I did this for a talk!), then with the same flow rate coming in, the level of water rises, because it requires more pressure at the base to drive water out at the rate required, to bring the system back into balance (when the level of water stops rising).

We are in both cases having the same amount of energy leaving as entering the system, but in the latter case, energy has been trapped in the system. 

This is a very good analogy for what happens with the Greenhouse Effect (see Note 4), and the level of water is analogous to the trapped energy (which means a hotter planet), and the world warms even though the rate at which energy is coming in (from the Sun) is constant. We can explain the Greenhouse Effect via this analogy simply:

The increased heat trapping power of the atmosphere with an increased concentration of COrestricts the exiting (infra-red) radiation to space – this is analogous to the reduced hole size in the container – and so …

The temperature of the Earth rises in order to force out radiation at the correct rate to balance the incoming energy – this is analogous to the increased level of water in the container. 

This demonstrates that the planet must stabilise the flow of energy out so that it equals the energy in, but with extra energy behind captured in the process (see Note 5).

The main point is that feedbacks do not inevitably mean there is a runaway.

Professor Pierrehumbert wrote a paper reviewing the possibility of a runaway in the sense of heading for a Venus scenario, and it seems unlikely “it is estimated that triggering a runaway under modern conditions would require CO2 in excess of 30,000 ppm”.

Even in more complex cases, such as melting sea ice and ice sheets, the feedbacks do not imply inevitable runaway, because in each case there is often a compensating effect that means a new equilibrium is reached.

But there is not one possible end state for a particular level of warming, there are numerous ones, and we know from the climate record that flips from one state to another can happen quite fast (the ocean conveyor belt transports huge amounts of heat around the planet and this is often implicated in these rapid transitions).

So, this is not to say that the new equilibirum reached is a good place to end up. Far from it. I agree it is serious, and the level of CO2 in the atmosphere is now unprecedented for over 3 million years. We are warming at an unprecedented rate, thousands of times faster than the Earth has seen in that period.

It is very scary and we don’t need to say a runaway is inevitable to make it even more scary!

Arguments that a feedback will trigger another, and so on, ad infinitum, may sound plausible but are not science, however confident and high profile the speaker may be. It does the XR cause no good to simply repeat wild speculation that has no scientific foundation, merely on the basis of a freewheeling use of the ‘precautionary principle’.

I hope this clarifies my point, which was not to minimise the urgency for action – far from it – I am 100% behind urgent action.

However, I think that sometimes it is important to be scientifically pedantic on the question of feedbacks and runaway. The situation is scary enough.

I really worry about the dystopian message for our collective mental health, and that this might freeze people and even limit action amongst the wider public who are not activitists (but need to participate in our collective actions).

We need a message of hope, and this is it:

The sooner we can peak the atmospheric concentration of CO2 (by stopping emissions), the sooner we can halt warming, and

the lower that peak in the atmospheric concentration, the lower the level of warming.

We can make a difference!

We have to act to make hope meaningful, because being alarmed, and frozen in the headlights, and unable to act, is not a recipe for hope.

However, being duly alarmed and having hope are not mutually exclusive, if we recognise we have agency. We can all make a contribution, to agitate for, or implement, a plan of actions and the actions that follow.

(c) Richard W. Erskine, 2019

 

NOTES

(1)   The IPCC 1.5C Special Report (p.64) talks about ‘committed warming’ in the oceans that is often assumed to mean that the Earth will continue to warm even when we stop CO2 emissions due to thermal inertia of heated oceans. Surprisingly for many, this is not the case. The IPCC reiterate what is a long known effect, regarding what they term the Zero Emissions Commitment:

“The ZEC from past COemissions is small because the continued warming effect from ocean thermal inertia is approximately balanced by declining radiative forcing due to COuptake by the ocean … Thus, although present-day CO2-induced warming is irreversible on millennial time scales … past COemissions do not commit substantial further warming”

(2)   This excludes clouds, and the effect of clouds at lower and higher levels can, for this simple example, can be regarded as cancelling each other out in terms of warming and cooling. Water Vapour in the atmosphere referred to here is not condensed into droplets but is a gas that is transparent to the human eye, but like carbon dioxide, is a strong absorber of infra-red. Because carbon dioxide is a non-condensing gas, but water does condense, it is the concentration of carbon dioxide that is the ‘control knob’ when it comes to their combined warming effect.  In 1905, T.C. Chamberlin writing to Charles Abbott, eloquently explains the feedback role of water vapour, and the controlling power of carbon dioxide:

“Water vapour, confessedly the greatest thermal absorbent in the atmosphere, is dependent on temperature for its amount, and if another agent, as CO2 not so dependent, raises the temperature of the surface, it calls into function a certain amount of water vapour, which further absorbs heat, raises the temperature and calls forth more [water] vapour …”

(3)  Strictly, it is a ‘black body’ – that absorbs (and emits) energy at all frequencies – that obeys Stefan’s Law. When using the law, we express T in Kelvin units. To a reasonable approximation, we can treat the Earth as a black body for a back of the envelope calculation, and we find that without carbon dioxide in the atmosphere, the Earth – at its distance from the sun – would be 258K, or -15oC on average, a frozen world. That would be 30oC colder than our current, or pre-industrial, average of 15oC.

(4) John Tyndall originated this analogy in his memoirs Contributions to Molecular Physics in the Domain of Radiant Heat published in 1872, although he used the example of a stream and dam, which is raised, my exposition is essentially based on his precedent.

(5) One other aspect of this re-established equilibrium is that the so-called ‘Top of Atmosphere’ (TOA) – where the energy out in the form of infra-red, is balancing the energy in – is at higher altitiude. The more carbon dioxide we add, the higher this TOA. Professor Pierrehumbert explains it in this Youtube exposition, from the film Thin Ice, where he pulls in a few other aspects of the warming process, as it works on planet Earth (e.g. convection).

END

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Google and the Internet: Friend or Foe to the Planet?

I keep hearing this meme that goes along the lines of “a Google search will use X amount of energy”, where X is often stated in a form of a scary number.

I think numbers are important.

According to one source a Google search is about 0.0003 kWh of energy, whereas a 3kW kettle running for one minute uses 3 x (1/60) = 1/20 = 0.05 kWh, which is 160 times as much (another piece  uses an equivalent figure – Note 1).

On the UK grid, with a carbon intensity of approximately 300 gCO2/kWh (and falling) that would equate to 0.09 gCO2 or roughly 0.1 gCO2 per search. On a more carbon intensive grid it could be double this, so giving 0.2 gCO2 per search, which is the figure Google provided in response to The Sunday Times article by MIT graduate Alex Wissner-Gross (cited here), who had estimated 7 gCO2 per search.

If the average Brit does the equivalent of 100 searches a day, that would be:
100 x 0.0003 kWh = 0.03 kWh, whereas according to Prof. Mackay, our total energy use (including all forms) is 125 kWh per person per day in UK, over 4,000 times more.

But that is not to say the that the total energy used by the Google is trivial.

According to a Statista article, Google used over 10 teraWatthours globally in 2018 (10 TWh = 10,000,000,000 kWh), a huge number, yes.

But the IEA reports  that world used 23,000 TWh in 2018. So Google searches would represent about 0.04% of the world’s energy on that basis, a not insignificant number, but hardly a priority when compared to electricity generation, transport, heating, food and forests. Of course, the internet is more than simply searches – we have data analysis, routers, databases, web sites, and much more. Forbes published findings from …

A new report from the Department of Energy’s Lawrence Berkeley National Laboratory figures that those data centers use an enormous amount of energy — some 70 billion kilowatt hours per year. That amounts to 1.8% of total American electricity consumption.

Other estimates indicate a rising percentage now in the low few percentage points, rivalling aviation. So I do not trivialise the impact of the internet overall as one ‘sector’ that needs to address its carbon footprint.

However, the question naturally arises, regarding the internet as a whole:

how much energy does it save, not travelling to a library, using remote conferencing, Facebooking family across the world rather than flying, etc., compared to the energy it uses?

If in future it enables us to have smarter transport systems, smart grids, smart heating, and so on, it could radically increase the efficiency of our energy use across all sectors. Of course, we would want it used in that way, rather than as a ‘trivial’ additional form of energy usage (e.g. hosting of virtual reality game).

It is by no means clear that the ‘balance sheet’ makes the internet a foe rather than friend to the planet.

Used wisely, the internet can be a great friend, if it stops us using planes, over-heating our homes, optimising public transport use, and so forth. This is not techno-fetishism, but the wise use of technology alongside the behavioural changes needed to find climate solutions. Technology alone is not the solution; solutions must be people centred.

Currently, the internet – in terms of its energy use – is a sideshow when it comes to its own energy consumption, when compared to the other things we do.

Stay focused people.

Time is short.

(c) Richard W. Erskine, 2019

 

Note 1

I have discovered that messing about with ‘units’ can cause confusion. So here is an explainer. The cited article uses a figure of 0.3 Watt hours, or 0.3 Wh for short. The more commonly used unit of energy consumption is kilo Watt hours or kWh. As 1000 Wh = 1 kWh, so it remains true if we divide both sides by 1000: 1 Wh = 0.001 kWh. And one small step means 0.1 Wh = 0.0001 kWh. Hence, 0.3 Wh = 0.0003 kWh.  If you don’t spot the ‘k’ things do get mighty confusing!

 

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Fusion is the Future

I mean it, it is the future.

Or rather, to be accurate, it could be the future.

In the core of the sun, the energy production is very slow, thankfully, so the beast lasts a long time. You need about 10,000,000,000,000,000,000,000,000,000,000 collisons between hydrogen nuclei before you get 1 that successfully fuses, and releases all that energy.

Beating those odds in a man-made magnetic plasma container (such as a Tokamak) is proving to be something that will be done by tomorrow, plus 50 years (and repeat).

Boris Johnson obviously believes that the way to show a flourish of leadership is to channel dreams of technical wizardry that goes well beyond the briefings from those experts in the know.

But who believes in experts in magneto-hydrodynamics? Stop over complicating the story you naysayer PhDs. Positive mental attitude will confound physics! Get back in your box experts!

*CUT TO REAL WORLD*

Man-made fusion energy as an answer to the man-made climate emergency by 2040 is not just ignorant, it is a deliberate and cynical attempt to delay action now. It is a form of techno-fetishism that deniers love. Boris Johnson spends a lot of time with these people.

We have relevant solutions available today, and just need to get on with them.

We do indeed have a functionally infinite fusion energy generator available to humanity, and it is free.

It’s called ‘The Sun’ (an astronomical entity, not a rag masquerading as a newspaper).

If man-made fusion energy is commercialised it *MAY BE* relevant to a world *POST*  resolving the climate crisis, but is definitely not part, or even maybe part, of that resolution.

It fails key tests I discussed here

Please politicians – left, right and centre – stop playing games and take the climate emergency seriously.

It may surprise you that while Boris’s cult following will swallow anything (almost literally), the rest, and particularly the rising youth, will not.

But I am prepared to compromise. A deal is possible.

Fusion is indeed the future …

… it is the energy from the Sun!

And you might be surprised to hear that it gives rise to …

direct Photovoltaic (PV) capture of that energy,

and indirect forms of capture (e.g. wind energy).

Problem solved.

As to man-made fusion, the jury is out (and a distraction for now), and we don’t have time to wait for the verdict.

 

(c) Richard W. Erskine. 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.

D5bh1ZmW0AAvOCd.jpg-large

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

 

Note:

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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Butterflies, Brexit & Brits

I attended an inspiring talk by Chris Packham in Stroud at the launch of Stroud Nature’s season of events. Chris was there to show his photographs but naturally ranged over many topics close to his heart.

The catastrophic drop in species numbers in the UK was one which he has recently written about. The 97% reduction in hedgehogs since the 1950s, and the Heath Fritillary has fallen by 82% in just a decade 

These are just two stats in a long list that attest to this catastrophe.

Chris talked about how brilliant amateur naturalists are in the UK – better than in any other country – in the recording of flora and fauna. They are amateur only in the sense that they do not get paid, but highly professional in the quality of their work. That is why we know about the drop in species numbers in such comprehensive detail. It appears that this love of data is not a new phenomenon.

I have been a lover of butterflies since very young. I came into possession of  a family heirloom when I was just 7 years old which gave a complete record of the natural history butterflies and moths in Great Britain in the 1870s. Part of what made this book so glorious was the intimate accounts of amateur scientists who meticulously recorded sightings and corresponded though letters and journals.

IMG_3828

The Brits it seems are crazy about nature, and have this ability to record and document. We love our tick boxes and lists, and documenting things. It’s part of our culture.

I remember once doing a consultancy for a German car manufacturer who got a little irritated by our British team’s insistence on recording all meetings and then reminding the client of agreed points later, when they tried to change the requirements late in the project: “you Brits do love to write things down, don’t you!”.

Yes we do.

But there is a puzzling contradiction here. We love nature, we love recording data, but somehow have allowed species to be harmed, and have failed to stop this? Is this a naive trust in institutions to act on our behalf, or lack of knowledge in the wider population as to the scale of the loss?

I heard it said once (but struggle to find the appropriate reference) that the Normans were delighted after conquering Britain in 1066 to find that unlike most of Europe, the British had a highly organised administration and people paid their dues. Has anything changed?

But we have our limits. Thatcher’s poll tax demonstrated her lack of understanding of the British character. We will riot when pushed too hard – and I don’t know what you think, but by god they frighten me (as someone might have said). Mind you, I can imagine British rioters forming an orderly queue to collect their Molotov Cocktails. Queue jumping is the ultimate sin. Rules must be obeyed.

I have a friend in the finance sector, and we were having a chat about regulations. I asked if it was true in his sector if Brussels ‘dictated’ unreasonable regulations – “Not at all he said. For one thing, Brits are the rule writers par excellence, and the Brits will often gold-plate a regulation from Brussels.”

Now, I am sure some will argue that yes, we Brits are rule followers and love a good rule, but would prefer it if it is always our rules, and solely our rules. Great idea except that it is a total illusion to imagine that we can trade in high value goods and services without agreeing on rules with other countries. 

In sectors like Chemicals and Pharmaceuticals where the UK excels, there are not only European regulations (concerning safety, licensing, event reporting, etc. – all very reasonable and obvious regulations by the way) but International ones. In Pharma, the ICH.org has Harmonization in its title for a reason, and is increasingly global in nature.

Innovation should be about developing the best medicines, not reinventing protocols for drug trials or the design of a drug dossier used for multi-country licensing applications. One can develop an economy on a level playing field.

The complete freedom the hard-right Brexiteers dream of rather highlights their complete lack of knowledge of how the world works. 

Do we really think we can tear up regulations such as REACH and still trade in in Chemicals, in Europe or even elsewhere? 

And are we really going to tear up the Bathing Water Directive?

Maybe Jacob Rees-Mogg fancies going to the beach and rediscovering the delights of going through the motions, but I suspect the Great British Public might well riot at the suggestion, or at least, get very cross. 

Richard Erskine, 10th July 2018

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Communicating Key Figures from IPCC Reports to a Wider Public

If you were to think about ranking the most important Figures from the IPCC Fifth Assessment Report, I would not be surprised if the following one (SPM.10) did not emerge as a strong candidate for the number one slot:

IPCC AR5 Figure SPM.10

This is how the Figure appears in the main report, on page 28 (in the Summary for Policymakers) of The Physical Basis Report (see References: IPCC, 2013). The Synthesis Report includes a similar figure with additional annotations.

Many have used it in talks because of its fundamental importance (for example, Sir David King in his Walker Institute Annual Lecture (10th June 2015), ahead of COP21 in Paris). I have followed this lead, and am sure that I am not alone.

This Figure shows an approximately linear1 relationship between the cumulative carbon dioxide we emit2, and the rise in global average surface temperature3 up to 2100. It was crucial to discussions on carbon budgets held in Paris and the goal of stabilising the climate.

I am not proposing animating this Figure in the way discussed in my previous essay, but I do think its importance warrants additional attention to get it out there to a wider audience (beyond the usual climate geeks!).

So my question is:

“Does it warrant some kind of pedagogic treatment for a general audience (and dare I say, for policy-makers who may themselves struggle with the density of information conveyed)?”

My answer is yes, and I believe that the IPCC, as guardians of the integrity of the report findings, are best placed to lead such an effort, albeit supported by skills to support the science communications.

The IPCC should not leave it to bloggers and other commentators to furnish such content, as key Figures such as this are fundamental to the report’s findings, and need to be as widely understood as possible.

While I am conscious of Tufte’s wariness regarding Powerpoint, I think that the ‘build’ technique – when used well – can be extremely useful in unfolding the information, in biteable chunks. This is what I have tried to do with the above Figure in a recent talk. I thought I would share my draft attempt.

It can obviously do with more work, and the annotations represent my emphasis and use of  language4. Nevertheless, I believe I was able to truthfully convey the key information from the original IPCC Figure more successfully than I have before; taking the audience with me, rather than scaring them off.

So here goes, taken from a segment of my talk … my narrative, to accompany the ‘builds’, is in italics …

Where are we now?

“There is a key question: what is the relationship between the peak atmospheric concentration and the level of warming, compared to a late 19th century baseline, that will result, by the end of the 21st century?”

“Let’s start with seeing where we are now, which is marked by a X in the Figure below.” 

Unpacking SYR2.3 - Build 1

“Our cumulative man-made emissions of carbon dioxide (CO2) have to date been nearly 2000 billion tonnes (top scale above)”

“After noting that 50% of this remains in the atmosphere, this has given rise to an increase in the atmospheric concentration from its long-standing pre-industrial value of 280 parts per million to it current value which is now about 400 parts per million (bottom scale above).”

“This in turn has led to an increase in averaged global surface temperature of  1oC above the baseline of 1861 to 1880 (vertical scale above).”

Where might we be in 2100?

“As we add additional carbon dioxide, the temperature will rise broadly in proportion to the increased concentration in the atmosphere. There is some uncertainty between “best case” and “worst case” margins of error (shown by the dashed lines).” 

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“By the end of the century, depending on how much we emit and allowing for uncertainties, we can end up anywhere within the grey area shown here. The question marks (“?”) illustrate where we might be by 2100.”

Can we stay below 2C?

“The most optimistic scenario included in the IPCC’s Fifth Assessment Report (AR5) was based on the assumption of a rapid reduction in emissions, and a growing role for the artificial capture of carbon dioxide from the atmosphere (using a technology called BECCS).” 

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“This optimistic scenario would meet the target agreed by the nations in Paris, which is to limit the temperature rise to 2oC.”

“We effectively have a ‘carbon budget’; an amount of fossil fuels that can be burned and for us to stay below 2oC”. 

“The longer we delay dramatically reducing emissions, the faster the drop would need to be in our emissions later, as we approach the end of the ‘carbon budget’.” 

“Some argue that we are already beyond the point where we can realistically move fast enough to make this transition.” 

“Generally, experts agree it is extremely challenging, but still not impossible.”

Where will we be in 2100?  – Paris Commitments

“The nationally determined contributions (or NDCs) – the amounts by which carbon dioxide emissions will fall – that the parties to the Paris Agreement put forward have been totted up and they would, if implemented fully, bring us to a temperature rise of between 2.5 and 3.5 oC (and an atmospheric concentration about twice that of pre-industrial levels).”

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 “Now, the nations are committed to increase their ‘ambition’, so we expect that NDCs should get better, but it is deeply concerning that at present, the nations’ current targets are (1) not keeping us unambiguously clear of catastrophe, and (2) struggling to be met. More ambition, and crucially more achievement, is urgent.”

“I have indicated the orange scenarios as “globally severe”, but for many regions “catastrophic” (but some, for example, Xu and Ramanathan5, would use the term “Catastrophic” for any warming over 3oC, and “Unknown” for warming above 5oC). The IPCC are much more conservative in the language they use.”

Where will we be in 2100? – Business As Usual Scenario

“The so-called ‘business as usual’ scenario represents on-going use of fossil fuels, continuing to meet the majority of our energy needs, in a world with an increasing population and increasing GDP per capita, and consequently a continuing growth in CO2 emissions.”

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”This takes global warming to an exceptionally bad place, with a (globally averaged) temperature rise of between 4 and 6 oC; where atmospheric concentrations will have risen to between 2.5 and 3 times the pre-industrial levels.”

“The red indicates that this is globally catastrophic.”

“If we go above 5oC warming we move, according to Xu and Ramanathan,  from a “catastrophic” regime to an “unknown” one. I have not tried to indicate this extended vocabulary on the diagram, but what is clear is that the ‘business as usual’ scenario is really not an option, if we are paying attention to what the science is telling us.”

That’s it. My draft attempt to convey the substance and importance of Figure SPM.10, which I have tried to do faithfully; albeit adding the adjectives “optimistic” etc. to characterise the scenarios.

I am sure the IPCC could do a much better job than me at providing a more accessible presentation of Figure SPM.10 and indeed, a number of high ranking Figures from their reports, that deserve and need a broader audience.

© Richard W. Erskine

Footnotes

  1. The linearity of this relationship was originally discussed in Myles Allen et al (2009), and this and other work has been incorporated in the IPCC reports. Also see Technical Note A below.
  1. About half of which remains in the atmosphere, for a very long time
  1. Eventually, after the planet reaches a new equilibrium, a long time in the future. Also see Technical Note B below.
  1. There are different opinions are what language to use – ‘dangerous’, ‘catastrophic’, etc. – and at what levels of warming to apply this language. The IPCC is conservative in its use of language, as is customary in the scientific literature. Some would argue that in wanting to avoid the charge of being alarmist, it is in danger of obscuring the seriousness of the risks faced. In my graphics I have tried to remain reasonably conservative in the use of language, because I believe things are serious enough; even when a conservative approach is taken.
  1. Now, Elizabeth Kolbert has written in the New Yorker:

In a recent paper in the Proceedings of the National Academy of Sciences, two climate scientists—Yangyang Xu, of Texas A. & M., and Veerabhadran Ramanathan, of the Scripps Institution of Oceanography—proposed that warming greater than three degrees Celsius be designated as “catastrophic” and warming greater than five degrees as “unknown??” The “unknown??” designation, they wrote, comes “with the understanding that changes of this magnitude, not experienced in the last 20+ million years, pose existential threats to a majority of the population.”

References

  • IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovern- mental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.
  • IPCC, 2001: Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change [Houghton, J.T., Y. Ding, D.J. Griggs, M. Noguer, P.J. van der Linden, X. Dai, K. Maskell, and C.A. Johnson (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 881pp.
  • Myles Allen at al (2009), “Warming caused by cumulative carbon emissions towards the trillionth tonne”,Nature 458, 1163-1166
  • Kirsten Zickfeld et al (2016), “On the proportionality between global temperature change and cumulative CO2 emissions during periods of net negative CO2 emissions”, Environ. Res. Lett. 11 055006

Technical Notes

A. Logarithmic relationship?

For those who know about the logarithmic relationship between added CO2 concentration and the ‘radiative forcing’ (giving rise to warming) – and many well meaning contrarians seem to take succour from this fact – the linear relationship in this figure may at first sight seem surprising.

The reason for the linearity is nicely explained by Marcin Popkiewicz in his piece “If growth of COconcentration causes only logarithmic temperature increase – why worry?”

The relative warming (between one level of emissions and another) is related to the ratio of this logarithmic function, and that is approximately linear over the concentration range of interest.

In any case, it is worth noting that CO2 concentrations have been increasing exponentially, and a logarithm of an exponential function is a linear function.

There is on-going work on wider questions. For example, to what extent ‘negative emissions technology’ can counteract warming that is in the pipeline?

Kirsten Zickfield et al (2016), is one such paper, “…[suggests that] positive CO2 emissions are more effective at warming than negative emissions are at subsequently cooling”. So we need to be very careful in assuming we can reverse warming that is in the pipeline.

B. Transient Climate Response and Additional Warming Commitment

The ‘Transient Climate Response’ (TCR) reflects the warming that results when CO2 is added at 1% per year, which for a doubling of the concentration takes 70 years. This is illustrated quite well in a figure from a previous report (Reference: IPCC, 2001):

TAR Figure 9.1

The warming that results from this additional concentration of CO2 occurs over the same time frame. However, this does not include all the the warming that will eventually result because the earth system (principally the oceans and atmosphere) will take a long time to reach a new equilibrium where all the flows of energy are brought back into a (new) balance. This will take at least 200 years (for lower emission scenarios) or much longer for higher emission levels.  This additional warming commitment must be added to the TCR. However, the TCR nevertheless does represent perhaps 70% of the overall warming, and remains a useful measure when discussing policy options over the 21st Century.

This discussion excludes more uncertain and much longer term feedbacks involving, for example, changes to the polar ice sheets (and consequentially, the Earth’s albedo), release of methane from northern latitudes or methane clathrates from the oceans. These are not part of the ‘additional warming commitment’, even in the IPCC 2013 report, as they are considered too speculative and uncertain to be quantified.

. . o O o . .

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Animating IPCC Climate Data

The IPCC (Intergovernmental Panel on Climate Change) is exploring ways to improve the communication of its findings, particularly to a more general  audience. They are not alone in having identified a need to think again about clear ‘science communications’. For example, the EU’s HELIX project (High-End Climate Impacts and Extremes), produced some guidelines a while ago on better use of language and diagrams.

Coming out of the HELIX project, and through a series of workshops, a collaboration with the Tyndall Centre and Climate Outreach, has produced a comprehensive guide (Guide With Practical Exercises to Train Researchers In the Science of  Climate Change Communication)

The idea is not to say ‘communicate like THIS’ but more to share good practice amongst scientists and to ensure all scientists are aware of the communication issues, and then to address them.

Much of this guidance concerns the ‘soft’ aspects of communication: how the communicator views themself; understanding the audience; building trust; coping with uncertainty; etc.

Some of this reflects ideas that are useful not just to scientific communication, but almost any technical presentation in any sector, but that does not diminish its importance.

This has now been distilled into a Communications Handbook for IPCC Scientists; not an official publication of the IPCC but a contribution to the conversation on how to improve communications.

I want to take a slightly different tack, which is not a response to the handbook per se, but covers a complementary issue.

In many years of being involved in presenting complex material (in my case, in enterprise information management) to audiences unfamiliar with the subject at hand, I have often been aware of the communication potential but also risks of diagrams. They say that a picture is worth a thousand words, but this is not true if you need a thousand words to explain the picture!

The unwritten rules related to the visual syntax and semantics of diagrams is a fascinating topic, and one which many – and most notably Edward Tufte –  have explored. In chapter 2 of his insightful and beautiful book Visual Explanations, Tufte argues:

“When we reason about quantityative evidence, certain methods for displaying and analysing data are better than others. Superior methods are more likely to produce truthful, credible, and precise findings. The difference between an excellent analysis and a faulty one can sometimes have momentous consequences”

He then describes how data can be used and abused. He illustrates this with two examples: the 1854 Cholera epidemic in London and the 1986 Challenger space shuttle disaster.

Tufte has been highly critical of the over reliance on Powerpoint for technical reporting (not just presentations) in NASA, because the form of the content degrades the narrative that should have been an essential part of any report (with or without pictures). Bulletized data can destroy context, clarity and meaning.

There could be no more ‘momentous consequences’ than those that arise from man-made global warming, and therefore, there could hardly be a more important case where a Tuftian eye, if I may call it that, needs to be brought to bear on how the information is described and visualised.

The IPCC, and the underlying science on which it relies, is arguably the greatest scientific collaboration ever undertaken, and rightly recognised with a Nobel Prize. It includes a level of interdisciplinary cooperation that is frankly awe-inspiring; unique in its scope and depth.

It is not surprising therefore that it has led to very large and dense reports, covering the many areas that are unavoidably involved: the cryosphere, sea-level rise, crops, extreme weather, species migration, etc.. It might seem difficult to condense this material without loss of important information. For example, Volume 1 of the IPCC Fifth Assessment Report, which covered the Physical Basis of Climate Change, was over 1500 pages long.

Nevertheless, the IPCC endeavours to help policy-makers by providing them with summaries and also a synthesis report, to provide the essential underlying knowledge that policy-makers need to inform their discussions on actions in response to the science.

However, in its summary reports the IPCC will often reuse key diagrams, taken from the full reports. There are good reasons for this, because the IPCC is trying to maintain mutual consistency between different products covering the same findings at different levels of detail.

This exercise is fraught with risks of over-simplification or misrepresentation of the main report’s findings, and this might limit the degree to which the IPCC can become ‘creative’ with compelling visuals that ‘simplify’ the original diagrams. Remember too that these reports need to be agreed by reviewers from national representatives, and the language will often seem to combine the cautiousness of a scientist with the dryness of a lawyer.

So yes, it can be problematic to use artistic flair to improve the comprehensibility of the findings, but risk losing the nuance and caution that is a hallmark of science. The countervailing risk is that people do not really ‘get it’; and do not appreciate what they are seeing.

We have seen with the Challenger reports, that people did not appreciate the issue with the O rings, especially when key facts were buried in 5 levels of indented bullet points in a tiny font, for example or, hidden in plain sight, in a figure so complex that the key findings are lost in a fog of complexity.

That is why any attempt to improve the summaries for policy makers and the general public must continue to involve those who are responsible for the overall integrity and consistency of the different products, not simply hived off to a separate group of ‘creatives’ who would lack knowledge and insight of the nuance that needs to be respected.  But those complementary skills – data visualizers, graphics artists, and others – need to be included in this effort to improve science communications. There is also a need for those able to critically evaluate the pedagogic value of the output (along the lines of Tufte), to ensure they really inform, and do not confuse.

Some individuals have taken to social media to present their own examples of how to present information, which often employs animation (something that is clearly not possible for the printed page, or its digital analogue, a PDF document). Perhaps the most well known example to date was Professor Ed Hawkin’s spiral picture showing the increase in global mean surface temperature:

spiral_2017_large

This animation went viral, and was even featured as part of the Rio Olympics Opening Ceremony. This and other spiral animations can be found at the Climate Lab Book site.

There are now a number of other great producers of animations. Here follows a few examples.

Here, Kevin Pluck (@kevpluck) illustrates the link between the rising carbon dioxide levels and the rising mean surface temperature, since 1958 (the year when direct and continuous measurements of carbon dioxide were pioneered by Keeling)

Kevin Pluck has many other animations which are informative, particularly in relation to sea ice.

Another example, from Antti Lipponen (@anttilip), visualises the increase in surface warming from 1900 to 2017, by country, grouped according to continent. We see the increasing length/redness of the radial bars, showing an overall warming trend, but at different rates according to region and country.

A final example along the same lines is from John Kennedy (@micefearboggis), which is slightly more elaborate but rich in interesting information. It shows temperature changes over the years, at different latitudes, for both ocean (left side) and land (right side). The longer/redder the bar the higher the increase in temperature at that location, relative to the temperature baseline at that location (which scientists call the ‘anomaly’). This is why we see the greatest warming in the Arctic, as it is warming proportionally faster than the rest of the planet; this is one of the big takeaways from this animation.

These examples of animation are clearly not dumbing down the data, far from it. They  improve the chances of the general public engaging with the data. This kind of animation of the data provides an entry point for those wanting to learn more. They can then move onto a narrative treatment, placing the animation in context, confident that they have grasped the essential information.

If the IPCC restricts itself to static media (i.e. PDF files), it will miss many opportunities to enliven the data in the ways illustrated above that reveal the essential knowledge that needs to be communicated.

(c) Richard W. Erskine, 2018

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