The debate over climate change is becoming more vitriolic by the week. The latest clash focuses on thousands of e-mails and documents, extracted by hackers from computers at the University of East Anglia, one of Britain's leading climate research centres.
Some sceptics see the electronic correspondence between UEA researchers and colleagues in the US as evidence of a vast conspiracy to overstate the scientific case for global warming and suppress contrary findings. Some scientists have defended the e-mails as legitimate private discourse of the sort that takes place in many research fields – and accused the sceptics of character assassination by quoting them out of context.
The most important point to make about the leaked correspondence is that it does not undermine the scientific case for cutting emissions of carbon dioxide to fight climate change, which is growing more rather than less compelling. None of the e-mails seized on by sceptics shows manipulation of the science itself.
What they do show, apart from some unfortunate personal remarks, is an excessive concern with presentation of their data – and a rather naive frustration that influential sections of public opinion fail to grasp what is to climatologists the self-evident need for urgent action against global warming.
Scientists must realise that they will not become popular by telling people to make big, expensive changes in their lifestyles to save the world from climate catastrophe. And they must not react to unpopularity by closing ranks against a hostile world or by feeling obliged to campaign for the cause.
Although the dividing line between research and campaigning can be hard to distinguish, scientists must try to respect it. Their value rests above all in the ability to provide evidence as objectively as possible. Politicians, businesses and environmental groups can then pick up the scientific evidence and base policies on it.
In the run-up to next month's Copenhagen conference we can expect more vitriol from both sides – from some of the more aggressive green groups as well as from the increasingly bold ranks of the sceptics. Whatever the provocation, scientists must continue calmly and openly to spell out the evidence for the climate change that is already happening, from polar melting to more intense tropical rainfall, and to issue predictions for the future based on their best computer models.
