Climate modelers look to the clouds.
Among the more than two dozen major climate models used to forecast future warming, those that focus on the role of moisture and clouds are proving to be the most accurate, according to analysis by scientists at the National Center for Atmospheric Research (NCAR).
Satellite monitoring has improved scientists' ability to glean less-cloudy data about clouds, enabling them to observe moisture in the atmosphere, measure water vapor, and track the global distribution of relative humidity. According to the study, this data projects lower relative humidity in dry zones and--with the anticipated increases in heat-trapping emissions--a higher temperature rise with all its impacts, including sea level rise, heat waves, and droughts.
"There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide," says NCAR scientist and study co-author John Fasullo. "Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections."
Source: National Center for Atmospheric Research, www.ucar.edu.