Will winds help cool a warming world?

Will winds help cool a warming world?

Climate experts have long considered clouds a major source of uncertainty in predictions of global warming. Now two physicists raise another question concerning clouds. John Latham and M.H. Smith of the University of Manchester Institute of Science and Technology in England propose clouds could help keep Earth cool if they get a little help from the wind.

As air currents blow over the ocean surface, they carry tiny drops of water up into the atmosphere, where the drops can serve as nuclei for developing cloud particles. In the Sept. 27 NATURE, Latham and Smith suggest that rising global temperatures might speed up winds and thereby increase the number of small particles within marine clouds. This effect would make clouds more reflective, helping to block sunlight before it reached Earth's surface. According to the researchers' rough calculations, winds must quicken by 50 to 100 percent in order to completely balance the warming initiated by a doubling in the atmospheric concentration of carbon dioxide. The scientists say experts must account for this wind-cloud relationship when using climate models to forecast future climate changes. They also suggest humans can potentially slow the warming by artificially generating more droplets, although they offer no suggestions on how to accomplish this feat.