Earth Has Warmed Over Half A Degree In Past 30 Years

December 10, 2008 4:33 p.m. EST

Huntsville, AL (AHN) - Globally, the Earth's atmosphere has warmed an average of about 0.72 degrees Fahrenheit (0.4 C) in 30 years, according to data collected from NOAA and NASA satellites. Over 80 percent of the planet has warmed by some measure.

Half of the globe has warmed at least half a degree Fahrenheit, and a quarter of the planet has warmed by at least one degree Fahrenheit, according to John Christy, a professor of atmospheric science and director of the Earth System Science Center (ESSC) at the University of Alabama in Huntsville.

A study of the Earth's climate change since 1978, when satellite sensors started tracking the climate, does not show a uniform global warming pattern. A map shows the planet hotter and the top, cold at the bottom, with varying degrees of warm in the middle.

The fastest warming area is near the Northern Atlantic and Artic oceans. The greatest warming has been in Greenland, where temperatures have risen as much as 4.6 degrees Fahrenheit in 30 years. During the same period, much of the Antartic has cooled, some by as much as Greenland has warmed.

"If you look at the 30-year graph of month-to-month temperature anomalies, the most obvious feature is the series of warmer than normal months that followed the major El Nino Pacific Ocean warming event of 1997-1998," said Christy in a statement. "Right now we are coming out of one La Nina Pacific Ocean cooling event and we might be heading into another. It should be interesting over the next several years to see whether the post La Nina climate 're-sets' to the cooler seasonal norms we saw before 1997 or the warmer levels seen since then."