Unsettled Science on Warming

Eric Berger, Science Editor for The Houston Chronicle, has an interesting blog on the certainty of the global warming models. Four years ago, after Al Gore's An Inconvenient Truth, he believed, "Humans were unquestionably warming the climate and changing the planet forever through their emissions of carbon dioxide." Now, he's beginning to ask questions like,

• If we can't have confidence in the short-term prognosis for climate change, how can we have full confidence in the long-term prognosis?
• Natural variations might also have played a role in the temperature run-up of the 20th century.
• Maybe there isn't a linear relationship between carbon dioxide and temperature, and maybe the planet will cool for a couple of decades even as carbon dioxide emissions accelerate.

He owes his shift to a report not by the anti-warming "deniers," but by leading climatologists who observe,

• We could be about to enter one or even two decades during which temperatures cool.
• But more and more agree that the short-term prognosis for climate change is much less certain than once thought.
• Natural variability is at least as important as the long-term climate changes from global warming.
• In the next few years a natural cooling trend would dominate over warming caused by humans. The cooling would be down to cyclical changes to ocean currents and temperatures in the North Atlantic.
• The dramatic Arctic ice loss in recent summers was partly a product of natural cycles rather than global warming.
• Climate model biases toward warming are also still a serious problem.

Berger is urging more humility and the acknowledgment of more uncertainty than has been voiced by the "settled science" of global warming.

What does all this say about the cost that "cap and trade" CO2 legislation will impose on our economy? What does it say about the reduction of development the West seeks to impose on India and China as it seeks to reduce CO2? Should we tax CO2 and impose tariffs on countries that don't?

(Source: "World's climate could cool first, warm later," 04 September 2009, New Scientist)