New Study Indicates That Warming May Decrease Low-level Clouds

Contrary to the supposition of many climate modelers, a new study suggests that rising temperatures over the world’s oceans may actually decrease the formation of low-level clouds, which in turn amplifies warming. In a study that examined more than 50 years of data, U.S. researchers found that as temperatures rose over a large section of the eastern Pacific Ocean, the incidence of low-altitude clouds decreased. Conversely, the researchers — reporting in the journal Science — discovered that during periods of cooling the amount of low-level clouds actually increased. Most climate models have projected that rising temperatures would mean the formation of more clouds, which would help cool the earth as more sunlight is reflected back into space. But the recent study — led by a scientist from the University of Miami — suggested that as ocean temperatures rose and atmospheric pressure fell, the opposite occurs. The study examined reports of cloud cover from mariners who were in the area between Hawaii and Mexico from 1952 to 2006. It also examined satellite records from 1984 to 2005, and both sets of data showed the correlation of higher temperatures and decreased formation of low-altitude clouds. Independent climate scientists said that the results could cause modelers to increase projections of expected warming this century.