This is a distinctive and courageous book. Mike Hulme is a geographer and climate modeller, a contributor to the Intergovernmental Panel on Climate Change (IPCC) and professor of climate change at the infamously hacked University of East Anglia. He must be acutely aware of the temptation not to give an inch. It would be entirely understandable if he presented to the world only assertions about the robustness and persuasiveness of the scientific understanding of climate change, and followed them up with strict warnings to take measures to limit further climate-damaging emissions.
But he has overcome this temptation in order to write a lengthy book on why people disagree about climate change. And his view is not, as one might expect from an IPCC insider, that people who disagree are uninformed and confused, or swayed by commercial interests, or bamboozled by clever denialists. He takes a much more anthropological, historical view than this, accepting that "the idea of climate change means different things to different people in different contexts, places and networks".
He doesn't mean that "anything goes", or that one can believe what one likes about the climate. Rather, he has come to the view that the connection between acting to address problems associated with the changing climate and the pursuit of the good life - living justly and wisely - can be drawn in a number of legitimate ways.
He makes it clear that his strong Christian beliefs are central to his position, not least because religious thinking tends to prompt questions about ultimate goals and values. We do not live merely to combat anthropic climate change. And, since we do not, we will want to include our ultimate goals in the choices we make now, which will affect the commitments we have in addition to our resolve to act on climate change (for example, to promote liberty, spirituality or the conservation of habitats).
Hulme adopts a straightforward plan for the book. After two chapters that set out the cultural and historical background to the very idea of a "climate" and more recent notions about how humans promote specific climate changes, the subsequent chapters all look at different reasons why people disagree about the subject.
These include straightforwardly social science considerations - how the media tend to cover climate change, and how environmental risks are conceptualised - and others that are more distinctive to the author, such as science and religious beliefs. It is evident that Hulme has taken all these issues to heart and has clearly spent a great deal of time reading the diverse literature. He cites Jean-Francois Lyotard, Bruno Latour and Harry Collins and draws on perceptively chosen news stories and quotes from political authorities.
His science chapter is particularly interesting, since it is here that the issue of the objectivity of climate change comes to the fore. Hulme writes very clearly about the nature of key climate projections ("Bayesian statements are no more or less than informed judgments about likelihoods"), and he compares estimates of the likelihood of future heatwaves with expert predictions for the next World Cup. A journalist or sociologist who drew this analogy would likely come in for some criticism, but Hulme is candid, and he follows it up with a telling example.
It is now well known that if the Greenland Ice Sheet (GIS) - basically all the ice piled up on Greenland - were to melt, it would raise sea levels by 5m to 6m worldwide. But how likely is this? Scientists don't know how much melting underneath the glacier might lubricate the ice and speed its slippage. In its publications, the IPCC has to take a view on this key question about the GIS, but Hulme describes how perfectly conceivable - although catastrophic - possibilities have been downplayed. In this case, the IPCC has leaned towards caution and conservatism. Scientific statements about climate change do contain subjective elements, but (at least here) the result of subjectivity is to understate possible threats.
The other chapters are all also interesting, although they generally read less authoritatively than the science one, which is based on Hulme's professional life. However, he recovers his full voice in the final chapter, where he emphasises that climate change is no longer a problem that can be "solved".
Climate change is already well under way and the changes already made to the atmosphere will not be undone for a generation, whatever steps are taken. In this sense the climate cannot be fixed. Moreover, many of the other goals that humans rightly have are likely to give rise to carbon dioxide emissions. Climate change is a "wicked problem" with no single, universal solution. Rather than pretend that we can fix the climate in isolation from everything else, Hulme argues, the "idea of climate change should be used to rethink and renegotiate our wider social goals about how and why we live on this planet".
Why We Disagree about Climate Change: Understanding Controversy, Inaction and Opportunity
By Mike Hulme. Cambridge University Press 432pp, £45.00 and £15.99. ISBN 9780521898690 and 73. Published 30 April 2009.