Wednesday, July 22, 2009

A Shockingly Fair Article About Global Warming in the New York Times

A Shockingly Fair Article About Global Warming in the New York Times

This July 20, 2009 article admits that there are real scientists (not just those slaves to Exxon!) who believe that solar cycle changes play at least some part in the global warming that happened at the close of the 20th century (and which is now curiously disappearing):
Among some global warming skeptics, there is speculation that the Sun may be on the verge of falling into an extended slumber similar to the so-called Maunder Minimum, several sunspot-scarce decades during the 17th and 18th centuries that coincided with an extended chilly period.
Most solar physicists do not think anything that odd is going on with the Sun. With the recent burst of sunspots, “I don’t see we’re going into that,” Dr. Hathaway said last week.
Still, something like the Dalton Minimum — two solar cycles in the early 1800s that peaked at about an average of 50 sunspots — lies in the realm of the possible, Dr. Hathaway said. (The minimums are named after scientists who helped identify them: Edward W. Maunder and John Dalton.)
With better telescopes on the ground and a fleet of Sun-watching spacecraft, solar scientists know a lot more about the Sun than ever before. But they do not understand everything. Solar dynamo models, which seek to capture the dynamics of the magnetic field, cannot yet explain many basic questions, not even why the solar cycles average 11 years in length.
And they even interviewed Henrik Svensmark:
But the overlap of the Maunder Minimum with the Little Ice Age, when Europe experienced unusually cold weather, suggests that the solar cycle could have more subtle influences on climate.
One possibility proposed a decade ago by Henrik Svensmark and other scientists at the Danish National Space Center in Copenhagen looks to high-energy interstellar particles known as cosmic rays. When cosmic rays slam into the atmosphere, they break apart air molecules into ions and electrons, which causes water and sulfuric acid in the air to stick together in tiny droplets. These droplets are seeds that can grow into clouds, and clouds reflect sunlight, potentially lowering temperatures.
Of course, they interviewed a cosmic ray expert who disagrees--but even his disagreement admits that there might be some connection:
Terry Sloan, a cosmic ray expert at the University of Lancaster in England, said if the idea were true, one would expect the cloud-generation effect to be greatest in the polar regions where the Earth’s magnetic field tends to funnel cosmic rays.
“You’d expect clouds to be modulated in the same way,” Dr. Sloan said. “We can’t find any such behavior.”
Still, “I would think there could well be some effect,” he said, but he thought the effect was probably small. Dr. Sloan’s findings indicate that the cosmic rays could at most account for 20 percent of the warming of recent years.

Hmmm. Considering how poor the data is on global warming, it makes you wonder what's actually left if even 20% of the difference is solar cycle.

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