"We face a true planetary emergency," Al Gore said yesterday in response to the announcement that he and the UN's Intergovernmental Panel on Climate Change (IPCC) had been jointly awarded the Nobel Peace Prize for their work. He added that "the climate crisis is not a political issue, it is a moral and spiritual challenge to all of humanity".
A planetary emergency, yes. A moral challenge, definitely. A spiritual challenge, perhaps. But very definitely, pace Mr Gore, a political issue. Indeed, Mr Gore's achievement, for which he is rightly being honoured, has been precisely his contribution to bringing the issue of climate change fairly and squarely into the political mainstream both in the US and internationally, to move it up the agenda of reluctant world leaders, and perhaps even to have helped energise and bring a new generation into politics through the issue.
The IPCC, for its part, was crucial in making such political advances possible - specifically the near unanimous acceptance of the fact of global warming and the majority acceptance of human causation - through its collection and authoritative presentation of the mass of data now available, earlier this year describing the evidence of warming as "unequivocal". But, while scientists may interpret the world, the point is to change it.
The hope that concern about climate change should allow politicians to transcend partisan politics is laudable, but the truth is that we are concerned here with the essence of politics: the struggle over the allocation of resources between rich and poor, competing values, the clash between interest groups resolved through political institutions, domestically and internationally.
Take the issue of allocation of responsibility and the cost of putting things right - the polluter pays principle. China is about to surpass the US in annual emissions of carbon dioxide, but it has contributed less than 8 per cent of the total emissions from energy use since 1850, while the US is responsible for 29 per cent and western Europe for 27 per cent. Who should pay for the ever-accumulating damage? How much? And how do we get them to pay? These are the fundamental questions, and they are all deeply-divisive political issues.
In awarding the prize to Mr Gore, the Nobel committee is making a similar point. Broadening the definition of "peace" to encompass environmental threats for only the second time since the prize's inception in 1901, the committee warned that "there may be increased danger of violent conflicts and wars" because of tensions over ever-scarcer resources caused by more floods, droughts, desertification and rising sea levels. Creeping desertification, for example, is widely seen as an underlying ingredient in the Darfur conflict.
We know what has been done, and what has to be done. The climate crisis is now essentially a crisis of leadership, a crisis of political will. Mr Gore's mobilisation of public opinion may be crucial to breaking that logjam.