Satellites Shed Light on a Warmer World

While winter may be approaching, researchers using data from satellites and weather stations around the world have found the air temperature near the Earth's surface has warmed on average by 1 degree F (0.6 degree C) globally over the last century, and they cite human influence as at least a partial cause.

Dr. James Hansen of Goddard Institute for Space Studies, New York, and Marc Imhoff from Goddard along with several other researchers analyzed records for 7,200 global weather stations and used satellite observations of nighttime lights around the planet to identify stations with minimal local human influence. Their findings appeared in a recent issue of the Journal of Geophysical Research-Atmospheres.

"Warming around the world has been widespread, but it is not present everywhere," Hansen said. Warming in the past 50 years has been rapid in Alaska and Siberia, but Greenland has become cooler. The lower 48 United States have become warmer recently, but only enough to make the temperature comparable to what it was in the 1930s.

For the complete article on global warming, go to: http://www.gsfc.nasa.gov/topstory/20011027heatisland.html