[Azure]

Hmmm....

"“It’s too simplistic to say low CO2 was the only cause of the glacial periods” on time scales of millions of years, said Robert Giegengack, a geologist at the University of Pennsylvania who studies past atmospheres. “The record violates that one-to-one correspondence.”....

He and other doubters say the planet is clearly warming today, as it has repeatedly done, but insist that no one knows exactly why. Other possible causes, they say, include changes in sea currents, Sun cycles and cosmic rays that bombard the planet.

“More and more data,” Jan Veizer, an expert on Phanerozoic climates at the University of Ottawa, said, “point to the Sun and stars as the dominant driver.”
Skeptics say CO2 crusaders simply find the Phanerozoic data embarrassing and irreconcilable with public alarms. “People come to me and say, ‘Stop talking like this, you’re hurting the cause,’ ” said Dr. Giegengack of Penn.

http://select.nytimes.com/gst/abstra...A80994DE404482

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