Study of Clouds to Focus on Global Warming


The Scripps Institution of Oceanography will orchestrate a potentially far-reaching national program to study whether clouds accelerate or slow global warming, Scripps officials said Thursday.

Under the $5-million program, funded by the National Science Foundation, researchers will try to solve the puzzle of how clouds function--an effort that could also lead to improved long-range weather prediction and understanding how acid rain forms.

“Clouds are emerging as a major player in the global climate puzzle,” said Veerabhadran Ramanathan, the Scripps professor of ocean and atmospheric sciences who will direct the Center for Clouds, Chemistry, and Climate.

“As the planet climate changes, just a small change of clouds is sufficient to amplify or reduce the greenhouse affect--but we don’t even know which way,” Ramanathan said. “In that sense, clouds are the major wild card.”


Scientists recently have realized that their lack of knowledge about clouds hampers their understanding of phenomena like global warming, a consequence of the industrial age and the burning of fossil fuels. Do the clouds help trap pollutants? Or do they help cleanse the atmosphere?

Carbon dioxide, which results from the burning of fossil fuels, has begun to build up--forming a blanket around the earth that traps the sun’s warmth. This action, some scientists say, could raise the earth’s temperature, increasing the average daily temperature anywhere from three to nine degrees. Global warming would also shift climate zones and raise the sea level.

Some scientists estimate that the havoc wreaked by these major changes could wipe out up to 15% of the plant and animal species alive today--giving more urgency to Ramanathan’s quest.

“The uncertain role of clouds is one of the primary reasons for our inability to make accurate predictions of global warming,” Ramanathan said. “Although clouds are believed to play a central role in regulating the radiative heating of the planet and in governing the transport of atmospheric gases, they are one of the most poorly understood phenomena in earth sciences.”


The Center for Clouds, Chemistry and Climate was formed last year at the University of Chicago where Ramanathan was a professor until 1990. When Ramanathan, the center’s director, moved to Scripps, the fledgling group’s research stalled.

National Science Foundation officials announced this week that the center would expand to include Scripps and that Ramanathan would direct the venture, which includes a consortium of research groups in the United States, Germany and Scandinavia.

Researchers from Chicago and Scripps will meet today to map out the center’s efforts, Ramanathan said.

“This center was Ramanathan’s conception,” said Frank Richter, chairman of geophysical sciences at Chicago, who will be the center’s associate director. “We are delighted that this has become a joint center with UCSD.” Scripps Institution of Oceanography is a division of UC San Diego.


To better understand the role of clouds, scientists plan to dispatch airplanes and use earth-orbiting satellites to gather data with remote sensing devices. Using this data, they hope to create computer models of global climate change at the San Diego Supercomputer Center.

“The issue we know the least about in climate research is what clouds do,” said Paul Crutzen, professor of atmospheric sciences at the University of Chicago. “Unfortunately, clouds are very difficult to understand. You just look out the window, well, in California, it’s so often cloud-free. But elsewhere, every time you look at cloud fields, it’s so totally chaotic.”