Prominent climate scientists say that discussion misses the bigger picture. The suggestion that global warming has stopped, says Richard Alley of Penn State, is "nonsense."

A recent paper by climate modelers at the Scripps Institution of Oceanography argues that the supposed pause in global warming can be explained entirely by recent variations in the El Nino-La Nina cycle in the tropical Pacific.

On Friday the IPCC, which is made up of several hundred climate scientists from around the world, will release a roughly 30-page summary of its new report tailored to the world's policy makers. Some time in the near future, the panel will release the 1,000-page report itself. (See "Leaked Report Spotlights Big Climate Change Assessment.")

It will be