title: CLIMATE: Ice, Mud Point to CO2 Role in Glacial Cycle.
abstract: The rhythmic stretching of Earth's orbit seems to drive glacial cycles, but how this feeble "orbital variation" could cascade through the climate system of air, land, water, and ice to produce the monstrous climate shifts of the ice ages has remained a mystery. On page 1897 of this issue of Science, a paleoceanographer finds a likely strongman to transmit and enforce the orbital variations' demands: carbon dioxide. Comparing records preserved in deep-sea muds with those in antarctic ice, he finds that orbital variations may muster carbon dioxide into and out of the atmosphere, and the resulting waxing and waning of greenhouse warming may drive the glacial cycle.
authors.forename: R A
authors.initials: RA
authors.lastname: Kerr