by Bill Bryson
There is a ruffianly quality to climate change, too. If and when it comes, it will not be exactly like any of the models. It will catch out governments and individuals. It may be brutal. If we do not do everything we can to lessen its effects, it will cause unprecedented wars and movements of population. We will lose the illusion of control we crave. We may have to give up many of the things we think we cannot do without. We will probably start to value what we have not valued enough only when much of it is already lost. However well prepared we are, we will have to learn very fast and react from day to day. Yet even if governments and electorates are not listening, some scientists are doing their best to inform us. (And so they should: the children of science are technology and industry, whose restless desire to adapt the world to human advantage has helped create this mess in the first place.)
IV
The Royal Society has been active in the climate change debate. As early as 1988, Margaret Thatcher used a Prime Ministerial address to the UK’s national scientific academy to acknowledge the dangers of global warming. From 1999 to the present, the Royal Society has produced a steady flow of policy statements, letters to government, workshops, events and guides for the lay reader on energy policy and global warming. Its policy reports on environmental issues range from the 1999 Nuclear Energy: The future climate, issued jointly with the Royal Academy of Engineering, to the 2008 Sustainable biofuels. In 2005, 2006, 2007 and 2008 the Royal Society initiated joint statements by the science academies of the G8 +5 countries calling world leaders to urgent action on global warming and saying that ‘G8 countries bear a special responsibility for the current high level of energy consumption and the associated climate change.’
A little further down the Thames, in Somerset House, another Royal Society, the Royal Society of Literature, holds its meetings and events. From 2004 to 2008 I was the RSL’s Chair of Council, and now I am one of its Vice-Presidents. What did we, as a body, do to show our concern about climate change during those years?
Er – nothing.
Many things could be said in our defence. True, the RSL is very much smaller, and over 150 years younger, than its scientific sibling the Royal Society. We have little money, few staff, the whole of literature to defend and support, and no expertise in meteorology or energy. Nevertheless, that’s not really the point. I think we writers as a group are just like my characters in The Flood, still walking through the streets of the drowned city, undeterred by the water rising up to our armpits from trying to get on with our lives as usual. Polls show that a majority of people in the UK believe global warming is a fact, and yet somehow they don’t believe it will really affect their lives, and they certainly don’t intend to change their own lives radically to help stop it happening. ‘Global warming is a problem – but not yet, o Lord, please’ is their unconscious prayer. Folk who DO take global warming seriously are thought slightly mad, or over-intense, unlike the sensible majority who just somehow know things will always go on as they do today. ‘It’s always been like this, so it always will be. Yes, we have had the odd over-hot summer, and springs come earlier, and maybe it seems cloudier and duller than before, but nothing’s really going to alter.’ And so, out of British politeness, climate change believers keep quiet. It’s like religion: don’t bring it up. Belief seems like a claim to virtue, a holier-than-thou-ness which will annoy others. Thus some of us, myself included, become cowards, or lazy. Easier to carry on as usual for us too. I am braver in my books, and yet I don’t expect to be loved for them. Perhaps climate change scientists have the same problem. None of us want to be bores. None of us want to be laughed at, or groaned over. And writers have a special vanity: we don’t want to be thought of as obvious, or preachy, because the subtlety and indirection of contemporary literary language is a cause of pride. In fiction, drama and poetry irony is over-valued, and consequently informativeness, moral depth and emotional truth become qualities not to be assessed, embarrassing to talk about, just as global warming is.
V
I don’t blame people for not wanting to peer over the cliff edge. It makes sound sense, in terms of immediate personal survival. Staying happy and optimistic helps people to be healthy. Becoming obsessional about the dangerous future does not help you to navigate the ordinary challenge of each day. Sometimes I myself see young people at global warming conferences almost driven mad by their attempts to live correctly, with a semi-religious belief that they can thus fend off catastrophe, thin and exhausted from taking their bikes on implausible journeys, unable to attend events that are genuinely essential for their work because they refuse to fly, hardly able to eat communally or even shop for food because everything they look at has an environmental cost they feel they cannot pay. I want to stop them and say, ‘Be kinder to yourself.’ I feel both admiration and pity for their terrible striving. In the end it seems to me we are only animals, and we can only be expected to do our best, not to be angels constantly stretched on the rack. Everyone born surely deserves a little happiness, a little bodily ease and pleasure. The choices always involve benefits and costs, but some of the young are already assuming all the costs and allowing themselves none of the benefits of life on this planet, whereas others, older and much, much richer, have taken all the benefits and paid none of the costs. How are we to strike a balance between self-indulgence and self-flagellation?
In our individual private lives, we will all have to answer that question. If rapid global warming does come, peer pressure will help us make up our minds quite quickly. Already there are the obvious things that everyone can do: walk more, talk about the issue more, drive less, buy less, fly less. In public life, though, scientists and artists play very different roles. To an artist, the scientist’s looks harder. Apart from everything else, when scientists make statements to the world, they are vouching, within defined limits, for the truth and solidity of what they say. Artists, on the other hand, are protected by the worn trench-coat of irony. We can place everything we say in distancing quotations; we have a thousand alibis. ‘This is fiction: this is a joke: this is a game: this is a confession I am half-ashamed of: this is just personal, take no notice if you don’t want to. It’s not me, it’s just a character. Don’t ask me, I’m an entertainer.’ It’s rather a cushy life we artists have made for ourselves, morally speaking. Scientists have never had the same exemptions.
On the plus side, though, climate scientists at least know clearly what they are doing, and what they can contribute. However many frustrations they have to cope with – financial constraints, deaf or dishonest governments, flawed climate models, inaccurate media reports – they do have a clear part to play. They are useful. Writers very often do not feel useful.
But are we, in fact, useful, and could we be more so? I think the answer is ‘Yes’ in both cases. Irony, humour and a distancing sense of history can be useful when we apply it critically where it is needed, in this case to the statements of both scientists and politicians. Science means ‘knowledge’, and it’s what writers very often lack. But with great knowledge can come an underestimation of what is still in doubt. Writers are good at casting doubt, and scepticism, in its place, is no bad thing. Great knowledge also brings a degree of power, another thing that writers lack. But again, power can bring with it a blindness to the limits of what it can achieve, a lack of humility. Some of the metaphors used by scientists to express the relationship between human beings and the world they live in are not good metaphors. Some, used so regularly they are barely noticed, in fact embody dangerous untruths. ‘Stewardship’ is a ubiquitous example. To call human beings ‘stewards’ of this planet is like accepting that Jack the Ripper is the right man to start a Home for the Care and Protection of Fallen Women. (James Lovelock once said in an interview that it was like putting a goat in charge of a garden.) In 2008, Wallace S. Broecker and that excellent writer Robert Kunzig, author of Mapping the Deep, published a survey of climate science called Fixing Climate. ‘Fix’ is a dangerous verb, short, glib and easy. Can
human beings really ‘fix’ the climate they are currently busy breaking? Do we understand enough even now to do it as easily as Kunzig’s peroration – ‘the planet is ours to run, and it is up to us to run it wisely’ – suggests? These are linguistic quibbles, but perhaps non-scientists can apply their critical intelligence also to the content of some of the remedies suggested by scientists for a globally warmed world. The history of science tells us that once radiation was used as a general tonic, and heroin recommended as a non-addictive alternative to oral morphine. We need a Jonathan Swift to ask sharp questions about the desirability of geothermal engineering along the lines some climate scientists have suggested. Is it really a good idea to seed the ocean with iron to increase the numbers of plankton? Would installing giant mirrors in the sky to reflect sunlight back make sense?
I think writers do have a few special talents we can hope to offer as we look apprehensively into our human future. We can try to defamiliarise the present, make our readers realise afresh how marvellous our living planet is. We can look at scientists’ discourse for evidence of solipsism or over-confidence. We suffer from both those traits ourselves, so we should recognise them in others. But in more important ways, both artists and scientists have a similar role to play. Both castes are fortunate to live lives that are not totally taken up with grubbing what we need from the texture of each day as it happens. We are not trying to survive in coalmines, or struggling to feed livestock. We have the great luxury of being able to look outside this immediate place and time. We can look beyond our own species, too, at the wide web of life which contains us. Unchained from the contingencies of the moment, our imaginations are free to scan the horizon and see the future coming in its many possible forms, and reach out towards it. If we tremble, it is because we are, as Shelley said, ‘the antennae of the race’. And if we do not make the attempt, if we sit blindly immured in what we have, we may lose everything. The laboratories and libraries that we need and love to pursue our crafts are some of the first things that would be lost with the collapse of civilisation. Doris Lessing’s novel Mara and Dann, set tens of thousands of years in the future after a time of great climatic change, imagines the rudimentary survival of only a few broken scraps of writing: a few lines of Shakespeare, though his name is lost. Planes no longer fly; museums have been ransacked and broken long ago. By imagining a darker future, Lessing imparts the golden light of imminent loss to the present. It is just one of the ways in which writers, by daring to look into the void, can help us both to appreciate and evaluate the complex human society that scientists are trying to shore up against ending.
19 STEPHEN H. SCHNEIDER
CONFIDENCE, CONSENSUS AND THE UNCERTAINTY CMOPS: TACKLING RISK MANAGEMENT IN CLIMATE HANGE
Stephen H. Schneider (1945–2010) was the Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies and Professor of Biology and Senior Fellow, Woods Institute for the Environment at Stanford University. He served as an author for the four assessment reports of the Intergovernmental Panel on Climate Change (IPCC), and was a core member for the third and fourth synthesis reports. He shared the 2007 Nobel Peace Prize with other IPCC authors and staff from the previous two decades. His popular books include The Genesis Strategy: Climate and Global Survival Global Warming: Are We Entering the Greenhouse Century?, The Coevolution of Climateand Life and Laboratory Earth: The Planetary Gamble We Can’t Afford to Lose. His last book was Science as a Contact Sport: Inside the Battle to Save Earth’s Climate.
UNCERTAINTY BEDEVILS COMPONENTS OF THE SCIENCE OF CLIMATE CHANGE. IT WILL NOT BE ELIMINATED FROM MANY ASPECTS ANY TIME SOON, SO THE BEST WAY TO HELP POLICY-MAKERS IS TO TRY AND FORGE A CONSENSUS ABOUT THE DEGREE OF CONFIDENCE THAT CAN BE ASSESSED FOR EACH IMPORTANT CONCLUSION. STEPHEN SCHNEIDER EXPLAINS THE LONG STRUGGLE TO UNDERSTAND HOW TO DO THAT EFFECTIVELY.
Human activities are changing the climate. But how large and how fast will these changes be? What systems will be only partly disturbed and what other systems seriously disrupted? And how can our policy choices reduce the threat they pose to natural and social systems?
The policy problem is hard because the global scale of climate change and its subtly intensifying impacts contrast uneasily with the short-term, local-to-national scales of most management systems. Furthermore, significant uncertainties plague projections of climate change and its consequences.
Such projections stretch the traditional scientific method of directly testing hypotheses because there can be no data for the future before the fact. Any prognostication into that unknown territory is, by definition, a model of the factors that are believed to determine how the future will evolve. But even though we can never fully solve the climate prediction problem, we can go a long way toward bracketing probable outcomes, and even defining possible outliers.
Progress here depends on an international community of scholars, who repeat what others have done with different computer models, make comparisons across models of various designs, compare relevant aspects of simulations to existing observational data to test model performance from ‘retrodiction’ of past changes, and pioneer new models as data and theory advance. Back in the early 1970s, when a reporter asked how long this model-building and validation process would take to achieve high confidence, I said that our models were ‘like dirty crystal balls, but the tough choice is how long we clean the glass before we act on what we can make out inside’. That is still the issue, even as models become more sophisticated and simulate the Earth’s conditions increasingly well. What constitutes ‘enough’ credibility to act is not science per se, but a subjective value judgment on how to gauge risks and weigh costs.
MODELLING FUTURE CLIMATE
How large are the scientific uncertainties, though? People often say that meteorologists’ inability to predict weather credibly beyond about ten days bodes ill for climate projection over decades. This misses a key difference between the instantaneous state of the atmosphere – weather – versus its time and space averages – climate. Even though the evolution of atmospheric conditions is inherently chaotic and the slightest perturbation today can make a huge difference in the weather a thousand miles away and weeks hence, large-scale climate shows little tendency to exhibit chaotic behaviour (at least on timescales longer than a decade). Good models can thus make reasonable climate projections decades or even centuries ahead if the processes forcing change are large enough to detect above the background ‘noise’ of the climate system – the unpredictable part. The Intergovernmental Panel on Climate Change (IPCC)’s laboriously compiled projections combine such modelling with scenarios for greenhouse gas emissions based on different assumptions about economic growth, technological developments, and population increase.1
These scenarios, despite major differences in emissions, show paths for global temperature increase that do not diverge dramatically until after the mid twenty-first century. This has led some to declare that there is very little difference in climate change across scenarios, and therefore, emissions reductions can be delayed many decades. That is a big mistake. It takes many decades to replace current polluting energy systems. There is also delay between emissions and temperature change due to the thermal inertia in the climate system caused by the large heat capacity of the oceans. After the mid twenty-first century, there are large differences based on emissions over the next few decades in the projected temperature increases – and the risks of associated dangers – for the late twenty-first century and beyond. Some of these risks imply irreversible changes.
Much of the uncertainty contributing to the ranges of projected future temperature increase derives from the so-called climate sensitivity. How much warming can we expect a given amount of greenhouse gas to cause? It is often estimated as the equilibrium global mean surface temperature increase due to a doubling of atmospheric CO2 from pre-industrial levels of about 280 parts per million. The IPCC estimates that it is ‘likely’ (there is a 66–90 per cent chance) that the climate sensitivity is between 2
and 4.5 °C and roughly a 5–17 per cent chance that it is above 4.5 °C (with the remainder being the chance it is less than 2 °C). They also offered a ‘best guess’ of 3 °C climate sensitivity.
Many studies have produced probability distributions for climate sensitivity with a long right-hand tail, meaning that high climate sensitivity values, while relatively unlikely, still register a probability of a few per cent or more. One example is displayed in figure 1, which shows a very uncomfortable 10 per cent chance that the climate sensitivity is higher than 6.8 °C. The median result – that is, the value that climate sensitivity is as likely to be above as below – is 2.0 °C, while there is a 10 per cent chance the climate sensitivity will be 1.1 °C or less. Like all model dependent studies, the detailed numerical values should not be taken literally, but the overall message must be taken seriously.
Our uncertainty goes beyond scientific understanding of the scale and distribution of climate changes from any single scenario of increasing greenhouse gases to include the trajectory of human development and our adaptive capacity. Moreover, future greenhouse gas emissions are heavily dependent on policy choices worldwide. But we do know that if we wait to act until an increase in undesirable impacts occurs, the inertia in the climate system and in the socioeconomic systems that produce greenhouse gas emissions will have committed us to even more severe impacts stretched out over many decades to centuries.
We cannot eliminate all of the important scientific uncertainties, but we can be more precise about their extent. That, however, is only part of the scientists’ job. We also have a responsibility to communicate all of this as well as we can. Communicating this complex systems science to policy-makers and the public is difficult. Too often, confusion reigns when an advocate for strong policy cites a well-established severe outcome as the most important consideration, and another advocate from some enterprise institute disliking public control of private decisions cites speculative components of the systems analysis as if that is all there were. Not surprisingly, politicians, media, and just plain folks get frustrated by this ‘duelling scientists’ mode of presentation, an unfortunate staple of the mainstream media.
