January 27, 2010
Goddard's surface temperature record shows an upward trend of about 0.2°C (0.36°F) per decade over the past three decades and a rise of 0.8°C (1.5°F) since 1880 since reliable record-keeping began in 1880.
2005 was the warmest year of the past decade and, by NASA's estimate, is the warmest year since 1880 (the U.N.'s World Meteorological Organization gives 1998 that title). 2009 was only slightly cooler than 2005, although it was the warmest year on record in the Southern Hemisphere. 2010 is expected to be even warmer due, in part, to the return of El Niño, a cyclical phenomenon.
These maps illustrate just how much warmer temperatures were in 2009 (top image) and the decade (2000-2009, lower image) compared to average temperatures recorded between 1951 and 1980 (a common reference period for climate studies). In both images, the most extreme warming, shown in red, was in the Arctic. Very few areas saw cooler than average temperatures, shown in blue in both time periods. Gray areas over Africa and parts of the Southern Ocean are places where temperatures were not recorded.
"There's substantial year-to-year variability of global temperature caused by the tropical El Niño-La Niña cycle," said James Hansen, the director of GISS. "But when we average temperature over five or ten years to minimize that variability, we find that global warming is continuing unabated."
REFERENCE: Voiland, A. (2010, January 21). 2009: Second Warmest Year on Record; End of Warmest Decade. NASA Goddard Institute for Space Studies. Accessed January 22, 2010.
NASA: 2009 second warmest year on record
(01/24/2010) According to NASA's Goddard Institute for Space Studies (GISS), last year was tied for the second warmest year on record after 2005, the warmest year on record. If just looking at the southern hemisphere, however, 2009 proved the warmest yet recorded since record-taking began in 1880. Overall 2009 tied a total of five other years—four from the 2000s—for the second warmest on record. But, researchers say what is most important was that the past decade, from January 1st 2000 to December 31st 2009, proved the warmest on record.