Green Affected How to blame humans for anything
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08 February 2010
Niche modeller David Stockwell is profoundly unimpressed with what’s billed as the latest “proof” of man-made warming - that winds are now pushing rain away from Western Australia, and dumping snow on Antarctica. And the funny thing is that not even the man spruiking this ”proof”, Professor Tas van Ommen, seems to have much faith in it:
The basic conclusion is that if this is being driven by human impact then you would expect it to continue but as climate change continues to change, the current situation changes too.
So if this keeps going, that’s evidence of man-made warming. And if it doesn’t, that’s evidence of climate change. It’s a win-win. And when you see van Ommen’s reasoning for assuming man is to blame you see exactly the same kind of heads-I-win-tails-you-lose reasoning:
This pattern has strengthened in the past 30 years and some of the computer models that reproduce this are showing that it looks like it has happened because of greenhouse gases – carbon dioxide – and also ozone (being depleted).
The models that reproduced this warming must be believed, but the blame-man ones that didn’t should be ignored.
And here’s the seal to the deal: this great change in the Antarctic oscillation just brings us to where we were in 1960. From Jones, J. M. and M. Widmann, 2004. Early peak in Antarctic oscillation index. Nature, 432, 290–291:
Here we reconstruct the austral summer (December–January) Antarctic oscillation index from sea-level pressure measurements over the twentieth century5 and find that large positive values, and positive trends of a similar magnitude to those of past decades, also occurred around 1960, and that strong negative trends occurred afterwards. This positive Antarctic oscillation index and large positive trend during a period before ozone-depleting chemicals were released into the atmosphere and before marked anthropogenic warming, together with the later negative trend, indicate that natural forcing factors or internal mechanisms in the climate system must also strongly influence the state of the Antarctic oscillation.
