Day By Day

Wednesday, May 24, 2006

More Scientific Follies -- The Solar Forcing Debate

A few years ago I had lunch with Harvard astronomer, Sallie Baliunas, and was fascinated to hear her ideas on global warming. On the basis of her experience as one of the top solar astronomers in the world, and former director of the Mount Wilson observatory, a center for solar research, she was of the opinion that one of the most important sources of warming was an increase in solar radiation output. At the time nobody was listening to her, because the political and professional commitment to anthropogenic causes of global warming was overwhelming, but I remembered what she said, because it scared me.

Now the concept of "solar forcing" is moving front and center in the warming debate. The Telegraph reports:
Global warming has finally been explained: the Earth is getting hotter because the Sun is burning more brightly than at any time during the past 1,000 years, according to new research.

Dr Sami Solanki, the director of the renowned Max Planck Institute for Solar System Research in Gottingen, Germany, who led the research, said: "The Sun has been at its strongest over the past 60 years and may now be affecting global temperatures.

"The Sun is in a changed state. It is brighter than it was a few hundred years ago and this brightening started relatively recently - in the last 100 to 150 years."

Interesting, and there's this:

The research adds weight to the views of David Bellamy, the conservationist. "Global warming - at least the modern nightmare version - is a myth," he said. "I am sure of it and so are a growing number of scientists. But what is really worrying is that the world's politicians and policy-makers are not.

"Instead, they have an unshakeable faith in what has, unfortunately, become one of the central credos of the environmental movement: humans burn fossil fuels, which release increased levels of carbon dioxide - the principal so-called greenhouse gas - into the atmosphere, causing the atmosphere to heat up. They say this is global warming: I say this is poppycock."

Read it here.

What struck me about this is the source of the new information. Sami Solanki was one of those who earlier dismissed Dr. Baliunas' claim that solar output drives global warming. Just four years ago Dr. Solanki stated precisely the opposite.
In the 2002 Harold Jeffreys Lecture to the Royal Astronomical Society in London, Solanki said: After 1980, however, the Earth's temperature exhibits a remarkably steep rise, while the sun's irradiance displays at the most a weak secular trend. Hence the sun cannot be the dominant source of this latest temperature increase, with man-made greenhouse gases being the likely dominant alternative.
Read it here.

Now there's nothing wrong with scientists changing their mind as new evidence comes in. That sort of thing lies at the heart of scientific inquiry. But, as I have argued time and again, the shifting sand of scientific opinion is a very unreliable foundation on which to build public policy.

My lunch with Dr. Baliunas made me aware of another thing. IAt one point I observed that it was a bit disquieting to hear that the Sun is a variable star. Everyone chuckled, but there was a serious and obvious point behind my observation. If solar output waxes or wanes there is absolutely nothing to do about it. We fry or freeze no matter what we do. In comparison, the idea of anthropogenic warming is downright comforting. The "unshakeable faith" in human agency in the matter of global warming might be based in the psychological need to believe that nature is benign and, more importantly, that we can control our own futures.

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