Similar to how a white shirt helps keep a person cooler in the summer than a black shirt, the cumulatively vast area of cloud cover around the world reflects large amounts of solar radiation falling on the planet's surface. If the reflective or insulative properties of clouds changed significantly, sunlight that otherwise would have been reflected back into space would get absorbed by the darker, denser mass of ocean and land. Don't count on clouds to come to the rescue if the Earth's current climate warming trend continues. That's according to new NASA research published in the October 1st issue of the American Meteorological Society's Journal of Climate . Heating and cooling of the Earth are influenced by cloud cover.
Clouds can act as a natural sun shield by reflecting light back into space.
But clouds can also coat the skies like a blanket, trapping warmth. Precisely how these competing attributes will change in response to a warmer atmosphere is not well understood. Anthony Del Genio of NASA's Goddard Institute for Space Studies in New York City, analyzed three years of observations of low clouds over land, a type of cloud thought likely to contribute to future cooling. Some climate theories predict that a warmer atmosphere would evaporate more water, and this additional water vapor would form thicker clouds. However, Del Genio's research found that when air temperatures were higher, clouds were thinner and thus less capable of reflecting sunlight.