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Politics : Formerly About Advanced Micro Devices -- Ignore unavailable to you. Want to Upgrade?

To: combjelly who wrote (832681)	1/26/2015 2:51:50 PM
From: Wharf Rat	Read Replies (2) \| Respond to of 1580018

Please Talk with Your Grandfather Two topics, one old and bedraggled, one important: 1. Swift-Boating In 1976, with four colleagues, I wrote my first paper on climate (Science, 194, 685-690, 1976). Based on the suggestion of Yuk Yung, one of the co-authors, we examined, for the first time, whether several human-made trace gases might have an important greenhouse effect (until then, only carbon dioxide and chlorofluorocarbons had been considered). We found that methane and nitrous oxide were likely to be important, though measurements of how these gases might be changing were not yet available. Starting then I became interested, very interested, in the Earth’s climate; indeed, two years later I resigned as Principal Investigator of an experiment on its way to Venus so that I could devote full time to studies of the Earth’s climate. So it was a bit of a surprise when I began to be inundated a few days ago with reports that I had issued proclamations five years earlier, in 1971, that the Earth was headed into an ice age. Here is how this swift-boating works. First on 19 September 2007 a Washington Times article by John McCaslin reported that a 9 July 1971 article by Victor Cohn in the Washington Post had been discovered with the title “U.S. Scientist Sees New Ice Age Coming”. The scientist, S.I. Rasool, is reported as saying that the world “could be as little as 50 or 60 years away from a disastrous new ice age”. This is an old story: Rasool and (Steve) Schneider published a paper in Science on that day noting that if human-made aerosols (small particles in the air) increased by a factor of four, other things being equal, they could cause massive global cooling. At Steve’s 60th birthday celebration I argued that the Rasool and Schneider paper was a useful scientific paper, an example of hypothesis testing, in the spirit of good science. But what is the news today? Mr. McCaslin reported that Rasool and Hansen were colleagues at NASA and “Mr. Rasool came to his chilling conclusions by resorting in part to a new computer program developed by Mr. Hansen that studied clouds above Venus.” What was that program? It was a ‘Mie scattering’ code I had written to calculate light scattering by spherical particles. Indeed, it was useful for Venus studies, as it helped determine the size and refractive index of the particles in the clouds that veil the surface of Venus. I was glad to let Rasool and Schneider use that program to calculate scattering by aerosols. But Mie scattering functions, although more complex, are like sine and cosine mathematical functions, simply a useful tool for many problems. Allowing this scattering function to be used by other people does not in any way make me responsible for a climate theory. Yet as this story passes from one swift boater to another it gets juicier and juicier, e.g.: Global Warming Scientist Once Warned of ‘Ice Age’ By Doug Ware – KUTV.com WASHINGTON – A NASA scientist, who is now sounding the alarm over global warming’s threat to the planet, once believed that pumping too many greenhouse gases into the air would have the opposite effect – a modern day ice age. James Hansen is currently among scientists who believe that carbon dioxide emissions are warming the planet’s atmosphere – posing a grave threat to the environment and humans’ ability to adapt to it. Many others – like public preachers Al Gore and Leonardo DiCaprio – share the same view in what seems to be the “hot button” issue of the moment. But 36 years ago, it appears, Hansen had a completely different warning – in what may be the scientific equivalent of a grandiose political ‘flip-flop’. In a Washington Post story dated July 9, 1971, Hansen – then a research associate at Columbia University – warned of a modern day ice age, which would cause the planet’s temperature to plummet as many as six degrees. The reason, he said then, was a fine dust emitted into the air via carbon dioxide pollution that would eventually become so dense that it would block sunlight and result in cooler temperatures – a scenario exactly the opposite of what leading climatologists say is happening now, that greenhouse gases are trapping heat inside the Earth’s atmosphere. Hansen and one of his research partners believed that the problem was so severe that the “ice age” could happen between five and ten years after the report – putting the prediction for extreme global cooling between about 1976 and 1981. It didn’t happen. Now a scientist for NASA, Hansen is facing criticism by some for an immense change of heart. How could he have predicted something so importunate at the time – only to make a 180- degree turn 35 years later, and completely head in the opposite direction? In fact the 1971 report even claims that Hansen and his associate dismissed the idea of global warming. “They found no need to worry about the carbon dioxide that fuel-burning puts in the atmosphere,” the Washington Post report said. It is little wonder that I have been getting nasty e-mails the past several days. But enough of swift-boating.... Jim Hansen columbia.edu