The Physical Science behind Climate Change

Why are climatologists so highly confident that human activities are dangerously warming the earth? Members of the IPCC, the 2007 peace winner, write on climate change. By William Collins, Robert Colman, James Haywood, Martin R. Manning and Philip Mote Members of the IPCC celebrating their Nobel Prize. Editor's note: This story was originally posted in the July 2008 issue, and has been reposted to highlight the long history of Nobelists publishing in Scientific American. For a scientist studying climate change, “eureka” moments are unusually rare. Instead progress is generally made by a painstaking piecing together of evidence from every new temperature measurement, satellite sounding or climate-model experiment. Data get checked and rechecked, ideas tested over and over again. Do the observations fit the predicted changes?... [read full story]