PS to the above - Bishop Hill (a skeptic)
posted this recently :
Quote:
What is the consensus? That carbon dioxide is a greenhouse gas? Yup. That man's activities are increasing carbon dioxide levels? Certainly. That temperatures went up at the end of the twentieth century and have not gone up since? Definitely. That human beings can affect the climate? Without a shadow of doubt.
Anything else? I don't think so. Even simple questions like whether observed temperature rises are anything out of the ordinary remain hugely controversial. The extent to which mankind has affected and will affect temperatures is likewise unknown, a great amphitheatre of ignorance dimly illuminated by a handful of aged CFLs - the climate models that scientists have pinned their hopes on - and little else. That these models are wrong is not in doubt - all models are wrong after all - but how wrong and how useful they are as tools to guide public policy is just another mystery. How can there possibly be consensus in these circumstances?
The impacts of climate change and the economics of climate change and policy responses to climate change are likewise entirely up in the air, with new hypotheses flown every day and shot down every evening and a mishmash of often contradictary empirical observations lending colour to the chaos. A glance tells you that there is no consensus.
So let us be clear, we don't even know if we have a big problem or a small one.
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