09-26-2005 - Earth

sagar: Author=’Abby Frank, Deborah Byrd’ program=’4649′ video=”Visit NASA’s Cloud Photo of the Month (NASA)_DB:_ This is Earth and Sky. Clouds are one of the biggest uncertainties in computer models of future global climate change.

_JB:_ Scientists are now keeping close track of clouds from Earth-orbiting satellites. “Bruce Wielicki”:http://208.96.63.114/?p=126 is Principal Investigator for CERES, a project using four instruments on two different satellites to sample every part of the Earth about four times a day. This project tracks what clouds are doing seasonally, year to year, across Earth.

_Bruce Wielicki:_ What we don’t know is what clouds will play as a role in future climate change. We know on average their role is cooling. We’re pretty sure they’ll still be cooling 100 years from now, but if they’re less cooling or more cooling, it can be either a positive or negative feedback on the climate change.

_DB:_ Wielicki said that, to test the accuracy of climate models, the models are used to predict current conditions.

_Bruce Wielicki: . . . for example, ask them to do things like when we go from El Ni?os to La Ni?as, do you get the right cloud changes? Or the seasonal cycle:_ as we go from winter to summer to spring do we get the right cloud changes?

_JB: He said children from some 1,500 schools in 60 countries are now making cloud observations – to help confirm the satellite data. For more on how “your school”:http://scool.larc.nasa.gov can help, come to earthsky.org. Our thanks today to “NASA:_ explore, discover, understand”:http://www.nasa.gov. We’re Block and Byrd for Earth and Sky.

Written by EarthSky