Monday, March 26, 2007

Six caveats about Six Degrees

Imagine that you find yourself behind the wheel of a large automobile tearing down a superhighway at high speed. Instead of a normal windscreen in front of you a video shows the view from where the car was a minute ago.

The first thing you would probably do in such a situation is take your foot off the accelerator. Next, you might look for some way to work out where you actually are now, where you are heading, and what you can you do about it.

In the case of anthropogenic climate change the time lag may be fifty or sixty years rather than sixty seconds, but the principle is the same. What we are seeing now are the consequences of what we did some time ago, and we cannot see directly the impact of what we are doing right now. Extending the analogy, slowing down means reducing emissions, while tying to work out where you are, where you’re heading and what to do requires (but is not limited to) paying attention to what the scientists are saying, working out what the best political and technical options are and how to make them happen.

What the scientists are saying is of course complicated but it boils down to this: anything more than a rise of something like 2 degrees Celsius (3.6° Fahrenheit) in average global temperature is (to borrow a phrase from Pulp Fiction) “pretty far from fxxxing OK”, and not a place we want to go. For graphics that say it all go to the fifth page of this document or the second page of this one.

The good news is that many sane people and some large institutions recognise this. The European Union, for example, has championed 2°C for some time. Empty words from bloated Eurocrits with a cissy aversion to shooting and torture first, or the foundation of a basic charter for the 21st century? As long as everyone else comes on board (Arnie’s already there and it seems even Al Qaeda has expressed an interest), and gets serious about what’s really involved in reducing the probability of rise exceeding about 2°C then there’s a chance that the challenge of adaptation will be manageable.

So much for the theory. In practice, of course, the 'everyone on board' and, more to the point, the 'get serious' parts are hard. What, then, to do?

One of the things that can help change minds and society is a good book. Silent Spring by Rachel Carson is probably the best known example. Writing in 1962, Carson warned that the reckless use of artificial pesticides and herbicides over the previous twenty years risked devastation for life on Earth:
Along with the possibility of extinction of mankind by nuclear war, the central problem of our age has…become the contamination of man’s total environment with…substances of incredible potential harm – substances that accumulate in the tissues of plants and animals and even penetrate the germ cells to shatter or alter the very material heredity upon which the shape of the future depends.
Silent Spring is a magnificent, angry work. It really did change how people thought and behaved in the United States and beyond. Today the greatest environmental threat is very different. It stems not from complex artificial chemicals but from a naturally occurring, simple compound so fundamental to nature that some Call it Life – harmless so long as it is not present in excessive concentrations.

And today shelf loads of passionate and eloquent books warn of the dangers of too much carbon dioxide and what to do about it. One author recently joked that he hoped his contribution would make the list of the one hundred best books on climate change from his small town in that year.

Six Degrees by Mark Lynas is one of the better recent efforts. Lynas, whose earlier High Tide was noted on openDemocracy here, structures his new book around what could be the impacts of one through six degrees Centigrade rise in average global temperature. It is a clever presentational device, and will help general readers get to grips with the issues (as we know, anything above two is pretty far from…OK). Easing in, Lynas explains,
…most people have [no idea] what two, four or six degrees average warming actually means in reality. These sound like very small changes when the mercury swings by fifteen degrees between day and night…it doesn’t mean the end of the world, it means we can leave the overcoat at home…But six degrees of global average change is an entirely different prospect.
Consider this: 18,000 years ago, during the deepest freeze of the last ice age, global temperatures were about six degrees colder than today…Where I sit writing, in [southern England], would have been just a dozen miles from the southern edge of the ice sheet, a freezing polar desert blasted by dust laden winds and suffering winter temperatures as low as -40°C
Some will probably call Six Degrees 'climate porn', tickling the ‘O my God we’re all going to die’ erogenous zone. If so, it is an extreme example of the genre, a climate snuff movie from the school that considers big feedbacks and tipping points in the climate to be more likely than gradual changes. It is an idea previously sexed up in book form by James Lovelock (now on three-for-two offer at all good bookstores), an unorthodox scientist who inspired a generation of climate scientists to include biological feedbacks in their models.

But I don’t think the ‘climate porn’ label is useful. As the novelist John Lanchester observes in a recent essay, even the people who feel most strongly about climate change seem to have a hard time believing in it, so great is its potential enormity. For this reason, and for others, describing the likely and the possible consequences of our actions in vivid terms – and doing so in one place rather than scattered across scores of news articles over the years – can help to concentrate the mind. (A good example, describing a different threat, is Jonathan Schell’s The Fate of the Earth of 1982).

In general, Six Degrees does this well (athough the prose isn’t helped by some clichéd writing: “The choice is ours…the clock is ticking”). This book is a handy and pretty heroic summary in accessible language of several hundred papers from the leading peer-reviewed scientific journals relevant to rapid climate change, generally taking the most pessimistic reasonable interpretation of what the scientists are saying. I recommend Six Degrees, with caveats that include these six.

First, the cover illustration is unhelpful. It would take sea level rise of about 60 metres (190 feet) to submerge St Paul’s Cathedral to its dome. As far as I know, no serious scientist is suggesting this will happen over the next few years or decades, which is how the cover is likely to be interpreted. (In the Oligocene, 30 million years ago, when the temperature was 3 to 4 degrees above today, sea levels were 70 metres higher. Some modelling indicates that if global average temperatures stabilise two degrees higher than the pre-industrial era, sea levels could rise by more than 50 metres, but the rise might take many thousands of years. The melting of the Greenland ice sheet, which some scientists consider one of the more likely if not already activated tipping points in the near term, could raise sea levels by 5 to 7 metres. Until recently it has been thought this could take millennia. A few now argue it could take much less time. A 5 metre sea level rise would be enough to devastate very large areas of London and many other major cities but not to wipe them out completely).

Second, to say this ‘degree by degree guide to the planet’s future’ is ‘unique’ is not right. A version goes back at least to the 'burning embers’ graph in the IPCC’s Third Assessment Report of 2001. The environmental group WWF has used a similar approach, and so did last year’s Stern Review on the economics of climate change which includes the two graphics mentioned above at the top of this article. Six Degrees does, however, give a compelling narrative form to the whole.

Third, a little too much of the uncertainty in the science and the complexity of the context in which climate change is taking place is sometimes ironed out in the interests of a good story. Take the account of Amazon ‘dieback’, a finding that if the global temperature rises by more about 3°C then the remaining forest dies, releasing more carbon and driving global temperatures another 1.5°C higher. It’s an iconic scenario (and is fore-grounded in cross-promotional material for Six Degrees in other News International products such as this Sunday Times article as if it were news; maybe to viewers with hearts grown brutal from the fare of 24 it is).

Scientists consider some dieback to be more likely than not if present trends continue (and maybe a one in ten chance even if we do make big emission cuts). The rest of us should listen hard to what they are saying. But my impression – based on what some researchers are saying, and observing and talking to delegates at major conference on the future of Amazon last week (see here and here) – is that a lot, including aspects of the modelling (particularly the key role of changes in sea surface temperature), is still uncertain. This is not to say the future of Amazon basin looks bright for those who like climax rainforest. Direct human impacts, including those associated with expanded ranching and ethanol production, may be even greater threats, especially in the first half of this century. But if these challenges are tackled effectively (a big if, requiring less destructive development and more justice), the forest may be more resilient under certain (but not all) circumstances to climate change. This slightly more subtle message may be harder to sell to the general public at present, and is unlikely to be one the general reader will take away from this book.

Fourth, Six Degrees lays itself open to being read as if a 6°C rise over the 21st century is inevitable if emissions increase at the kinds of rate that currently seem most likely. The author acknowledges this pitfall in his introduction: “…a temperature based approach makes giving dates very hazardous. The world could become two degrees warmer by 2100, or it could already have hit that level as soon as 2030”. But then he falls into it, or comes pretty close, bound in the straightjacket of the book’s structure. On page 102 a temperature rise of 0.4°C per decade is described as a ‘likely scenario’; page 127 points to a 3°C rise by 2050; on page 223, 5°C is ‘a few decades from now’; and Chapter 6 outlines a scenario for 6°C by 2100.

Such a rate of change is possible. The summary of the IPCC’s Fourth Assessment Report, for example, indicates a rise by 2100 in the range of 1.1 to 6.4°C depending on how much feedback there is in the Earth system and, of course, the way humanity generates and uses energy and manages land and ocean. The IPCC says that with a doubling of atmospheric CO2 the most likely rise is between 2 and 4.5°C with a best estimate of about 3°C. Warming over the next two decades, it says, is likely to be about 0.2°C per decade. The estimate may be conservative. Climate sensitivity could be more (see, for example, Stainforth), and it could also be less.

But even if climate sensitivity is at the higher end of the predicted range – say between 3 and 4°C to a doubling of CO2 – that does not necessarily mean the consequences will play out over the next ninety to a hundred years. And climate change doesn't have to happen before 2100 to be bad news. Climate tipping point guru John Schellnhuber gives the example of an unstoppable mobilisation of methane clathrate. It could, he says, be set in motion this century, but could about take a thousand years to fully play out, with truly massive consequences over that time frame: more ‘tapping point’ than ‘tipping point’.

The fifth caveat is that Six Degrees makes only a brief contribution on perhaps the biggest of all questions: what humanity needs to do to get its act together. It notes correctly that some official government statements in Britain with regard to how much and how fast emissions need to be reduced have been excessively cautious given some of the advice officials have received from the scientific community. There was, for example, an inconsistency between (on the one hand) some work commissioned for the landmark 2005 conference Avoiding Dangerous Climate Change, which suggested a target for atmospheric concentrations of greenhouse gases of less than 450 parts per million C02 equivalent would be prudent, and (on the other hand) statements in 2006 by the UK government’s chief scientist that stabilisation at 550 ppm would be OK. Six Degrees does not mention that the influential Stern Review, published in October 2006, also finessed this issue. Given the quality of its advisors, the German government may be bolder, at least in its rhetoric, in its presidencies of the European Union and the G8 this year.

Six Degrees makes the familiar and in my view correct criticism of biofuels as likely to make only a small contribution a solution at best, with significant downsides. It concludes that individual carbon rationing is the key to progress. Rationing is a fashionable idea, and may have some merit, but is not itself a solution. An individual rationing system can only make a useful difference once substantial emission reductions, and the means to achieve them, are already agreed. Even then, it would probably be just one of the tools in the box, and not necessarily the most significant one.

The sixth and final caveat regarding this book is with regard to how it, and other alarming projections, may shape feeling and action. The author writes that it does not occur to him to get depressed. He compares the situation to finding a fire in your kitchen: you don’t just sit there getting depressed as the fire spreads; you do something about it.

The analogy is beguiling, but not adequate. Climate change is so much bigger and more complicated. It can leave drive some very good minds to extreme statements. Feeling overwhelmed and pessimistic is a rational first reaction following any thorough review of evidence and trends. This is why it is not always helpful to frame psychological reactions through the lens of denial: for many people, acceptance and fatalism would be more like it; and there are more than a few who would like to throw a lighted match on petrol. It is also important to acknowledge fear and grief at what looks likely to the continuing loss of countless living forms most beautiful and most strange – the ‘end of the wild’ and the ‘death of birth’.

It is probably necessary to work through all of these feelings to find hope that is well grounded, if there is any. Being solipsistic may help: having perceived and experienced in one's own life even a fraction of wonderful existence is a good start. At least that experience has been real for the individual, something to give thanks for, and a place to start looking for hope. (In my own case, I can thank my being on dark nights in October 1962 at the height of the Cuban Missile Crisis. With the fate of at least several hundred million human beings on a hair trigger [if the 36 year old Castro had had his way Soviet field commanders would have initiated a nuclear exchange that would have engulfed North America, the USSR and Europe: operationalising ‘socialism or death’, I guess], my parents went to bed with a good bottle of wine and the novels of Jane Austen. I appeared on midsummer’s day the following year, and am still glad to be here.)

On the first day of spring this year Al Gore told members of the US Congress, "Our world faces a true planetary emergency. I know the phrase sounds shrill, and I know it's a challenge to the moral imagination." He is right, but there’s more to it even than he said. Climate change is a challenge to every aspect of the human imagination – moral, scientific, technical, artistic, you name it. Above all it is a challenge to our sense of time, and a tendency amongst many of us to procrastinate while most of what we see out of the car window isn’t too bad.

At their best, people can be capable of some very grand ideas with regard to time, connection and value. (It doesn’t cease to impress me that long before the modern scientific era Hindu and Buddhist cosmology conceived the Kalpa, one day of Brahma the creator, as 4,320 million years, which is not too far off the best estimate of the earth’s actual age of approximately 4,600 million years.) If people can sometimes understand something of the very big, they can too the very small, and even the medium: the span of one, two or three generations ahead that are hazy to us most of the time but also right at our hearts through our children born or unborn.

On that scale, there may be a good chance of keeping climate change within the range of the manageable, but not always pleasant. Up to about 2°C (and there is no magic number) over a century a lot of life can probably adapt and re-configure, albeit at some cost. And if not, then as the late Czeslaw Milosz put it:

…perhaps we’ll say nothing of earthly civilisation.
For nobody really knows what it was.

[P.S. 26 March: An edited version of this article has now been published here on openDemocracy]