Rumor Debunked: No Flip-Flop on Global Warming

Claims are floating around the blogosphere that the American Physical Society, the leading professional organization for physicists, has reversed its position on global warming.

But on its Web site, the APS has reaffirmed that it supports the consensus view that human-caused greenhouse gas emissions are warming the planet.

Part of the statement the society adopted on Nov. 18, 2007, states: "Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate."

Stories of the supposed policy reversal began popping up after an article by Christopher Monckton, a politician and a former policy advisor in Margaret Thatcher's administration, submitted an article in an online newsletter of the APS Forum on Physics and Society. The article claimed that the Intergovernmental Panel on Climate Change (IPCC) had overestimated the Earth's climate sensitivity to carbon dioxide (or how much the global average temperature will change given a certain amount of carbon dioxide entering the atmosphere).

In the article, Monckton, the 3rd Viscount Monckton of Brenchley, also claims that changes in solar activity are behind the warming trend of the past few decades, an idea that has been refuted by several climate scientists.

A note in red lettering above the article states that it has not been peer-reviewed and that "its conclusions are in disagreement with the overwhelming opinion of the world scientific community. The Council of the American Physical Society disagrees with this article's conclusions."

On their homepage, the APS has now placed a statement that reaffirms its 2007 position statement on global warming, which also states, "The evidence is incontrovertible: Global warming is occurring." It adds that mitigation efforts must be taken immediately.

• Video: Goldilocks and the Greenhouse
• Global Warming: How Do Scientists Know They're Not Wrong?
• Timeline: The Frightening Future of Earth