Upstart Ice Age Theory Gets Attentive but Chilly Hearing

摘要

Selling a new gizmo to replace a longtime favorite is always a tough job--especially if few are convinced that the original is broken. Physicist Richard Muller of the University of California, Berkeley, knows what it's like: For several years, he hasbeen pitching a new way to drive the comings and goings of the ice ages. He's trying to displace the cherished Milankovitch mechanism in which cyclical changes in the elliptical shape of Earth's or-bit shift the pattern of solar heating, trigger-ng the buildup or melting of ice sheets.