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Past Decade Declared Warmest on Record

Scientists from three leading climate research centers have concluded that this past decade was the warmest since global temperatures were first recorded more than a century ago, with the first half of 2010 potentially topping the charts. Overall trends indicate a rise in global temperatures during the last five decades, with each of the last three being "much warmer" than the decade before it. The report also tells where much of this heat is ending up, stating "More than 90 percent of the warming that's happened on Earth in the past 50 years has gone into the oceans."

NOAA

This is among the conclusions recently published in the 2009 "State of the Climate" report, a special supplement in the June 2010 issue of the Bulletin of the American Meteorological Society. For this report, more than 300 authors from 48 countries assessed all aspects of Earth's climate system. They used 10 measurable planet-wide features to gauge global temperature changes. Seven are rising: air temperature over land, sea-surface temperature, air temperature over oceans, sea level, ocean heat, humidity and tropospheric temperature in the "active-weather" layer of the atmosphere closest to the Earth's surface. Three are declining: Arctic sea ice, glaciers and spring snow cover in the Northern hemisphere.

NOAA's National Climatic Data Center and NASA's Goddard Institute for Space Studies, which contributed to the "State of the Climate" report, declared the first half of 2010 the hottest on record. The UK Met Office, which also contributed to the report but uses only temperature observations, agrees that the Earth has been growing warmer during the past half century, however says that only January and March of 2010 surpassed 1998's high during these months and so 1998 was still hotter overall during its first half.

Director of NOAA's National Climatic Data Center Thomas Karl said at a Capitol Hill briefing on August 4 that, "There were a number of different groups using a number of different approaches to look at the same variables. We can see that while they aren't all identical, they all line up and show a similar trend."

In a NOAA press release, the Under Secretary of Commerce for Oceans and Atmosphere and NOAA Administrator Jane Lubchenco said, "For the first time, and in a single compelling comparison, the analysis brings together multiple observational records from the top of the atmosphere to the depths of the ocean. The records come from many institutions worldwide. They use data collected from diverse sources, including satellites, weather balloons, weather stations, ships, buoys and field surveys. These independently produced lines of evidence all point to the same conclusion: our planet is warming."

For more information:

NOAA "2009 State of the Climate" report, summary & supplemental materials >>

"State of the Climate" video >>