| For the week of July 2, 2007 |
Global Warming Made Simple |
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There’s a new theory of global warming that is so simple even a caveman can understand it. Of course, a caveman would worry more about ice ages, but let’s assume for a moment that global warming concerned him too.
If a caveman thought the Earth was warming up, he had two obvious theories to choose from. Perhaps it was due to his increasing use of fire. The other possibility was the big orange disk in the sky, the sun.
Even to the caveman this was a no-brainer. The fire he used for warmth and cooking was nothing compared to the heat of the sun.
Fast-forward to today and our choices of theories to explain global warming are more numerous and complex, but not that totally different. The popular theory is that carbon-dioxide and other greenhouse gases are warming the atmosphere. Carbon dioxide is formed in the burning of fossil fuels among other things. Therefore, the cause is largely attributable to human activity.
But a Danish scientist, Henrik Svensmark, thinks the sun is playing the major role in global warming. In the July, 2007 Discover magazine, Svensmark, who is director of the Center for Sun-Climate Research at the Danish National Space Center in Copenhagen, blamed the sun and cosmic rays for altering cloud formation. His basic idea is that the sun can make the sky more or less cloudy.
In the Discover interview, Svensmark said, “And if the sun and the solar wind are very active – as they are right now – they will not allow so many cosmic rays to reach the Earth. Fewer cosmic rays mean fewer clouds will be formed, and so there will be a warmer Earth.”
The simplicity of this theory belies the work that Svensmark and his colleagues have done on it. They’ve spent years experimenting in a chamber that produced all the effects they needed to test the theory. In the end, Svensmark decided that climate is determined by the clouds and not the other way around.
This doesn’t mean that Svensmark completely dismisses greenhouse gases, because he doesn’t. He just thinks that carbon dioxide emissions are affecting climate change much less than is popularly thought. And the climate models that are the root of most dire predictions cannot model clouds so they are really poor, in his opinion.
The article’s author, Marion Long, said there is really no greater scientific heresy today than questioning the warming role of CO2, but Svensmark’s theory is disturbing in another way as well. If he is right, there is really little that can be done about global warming.
Some of the harshest criticism of the Danish scientist’s work seems to be coming out of the United Nations. An even-handed new book on climate change admitted that the effect of clouds is “complex and not perfectly understood.”
For agriculture and the rest of us, there is no escaping the debate over global climate change. Farmers are concerned about international environmental treaties, new regulations, added layers of bureaucracy and the inevitable cost, and what if the science behind it is wrong or politically motivated?
A caveman could have shrugged the whole thing off, but we can’t.
Stewart Truelson is a regular contributor to the Focus on Agriculture series.