(28 May)  In Philip Kitcher’s wide-ranging essay in Science on ‘The Climate Change Debates’ I am struck by two things – which are not very new, but which are very important. First, is how the framing and public discourse around climate change differs between countries: as Kitcher puts it, where ‘societies … are inclined to see matters differently’. This is brute fact sociological reality, just as non-negotiable as the radiation physics of a CO2 molecule. Recognising this means that as soon as scientific knowledge enters public discourse – whether this knowledge is robust, imprecise or tentative – different things will happen to it and different social realities will be constructed around it. For me, this is the essence of the climate change phenomenon.  
 
The second, related, thing to emphasise is how predictive claims about the climate future – and its impacts – are inextricably bound up with imaginations (e.g. scenarios) and value judgements (e.g. discount rates) about the future. One could argue that such considerations fall within the legitimate reach of ‘climate science’ and the elite scientific expertise Kitcher claims any genuine democracy needs. But for me it is these extra-scientific dimensions of climate change ‘knowledge’ which motivated me in my book ‘Why We Disagree About Climate Change’ to challenge a narrow appeal to science for engaging our publics around the idea of climate change. It really is not about ‘getting the science right’. It is just as much about engaging our imaginations, about facing up to the ways different peoples and cultures construct meaning for themselves, about the very different values we attach to the future. And because of this I don’t believe Cassandras such as Jim Hansen and Steve Schneider should have the last word.”