Monday, October 25, 2010

Hal Lewis Knocks Out Hal Lewis in the First Round

Hal Lewis, the physicist who two decades ago warned about the dangers of greenhouse gas warming, has become a cause celebre for now changing his mind and now coming out against the problem. Anthony Watts even somehow managed to get an op-ed published in the Christian Scientist Monitor, proclaiming Lewis as the next Martin Luther, the most hyperbolic statement I think I have ever encountered in my life.

Anyway, Lewis told Revkin something that gives away the game:
I believe I was chairing JASON in the early 1970s when Gordon MacDonald ran our first computer modeling on the subject, and the results were not all that different from what people get now using the same methods.

In other words: The science of greenhouse gases is so straightforward that 35 years of advances in computer science and climate science have hardly changed the major result. Actually, they’re now even that from what Arrhenius calculated, by hand, over a hundred years ago.

That is to say: Greenhouse gases warm planets, and more of them warm it more. That's the problem in a nutshell.

We need to know all the details, but this is the basic concern, not whether climate models predict the exact year of the last Himalyan glacier. In one sentence, Lewis succinctly states what all the hoopla is about – and he doesn’t even seem to recognize it.

PS: Indeed, Lewis wrote in his book: "The broad outline is clear."

Also, he told Revkin: 
No one knows how much humans can (your word) warm the planet — the science is complicated. It might be a degree or two (Celsius) per century, but anyone who says he knows is committing fraud.
This is a very irresponsible use of the word "fraud," because, of course, climate scientists don't say they know how much warming will occur -- the IPCC ARs give a relatively wide range for the prediction. Surely Lewis has heard of error bars?

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