RP Sr joins the ranks of people telling us its been hot/cold somewhere on earth in some month, but more interestingly points to an essay by Carl Wunsch. Its one of a series, by various worthies, including TIm Palmer. I’m not quite sure what the point is, though… they don’t seem to be much good… if you want to know about GE, youre better off with the wikipedia article.
Wunschs article is particularly stupid (yes I know he’s a great man, that doesn’t mean he doesn’t say stupid things on occaision) that (I paraphrase) concludes that since the ice ages caused big changes in the past we therefore can’t attribute current change to human activity. You can pretty well throw away the entire article except for the end para (and had he done that I wouldn’t be complaining too much), which is:
Thus at bottom, it is very difficult to separate human induced change from natural change, certainly not with the confidence we all seek. In these circumstances, it is essential to remember that the inability to prove human-induced change is not the same thing as a demonstration of its absence. It is probably true that most scientists would assign a very high probability that human-induced change is already strongly present in the climate system, while at the same time agreeing that clear-cut proof is not now available and may not be available for a long-time to come, if ever. Public policy has to be made on the basis of probabilities, not firm proof.
Sure, its very difficult to separate human and natural change. Its very hard to build a nuclear reactor, but people do it. A lot of clever people have spent a long time working on the attribution issue, and the answer is, its us, to some degree of probability. Throwing in “proof” is a red herring – there is no proof outside of maths.