The U.S. National Oceanic and Atmospheric Administration released a report today on 2009's climate, which says the decade of the 2000s was the warmest since readings were first kept. In a phone interview with reporters today, Peter Thorne of the Cooperative Institute for Climate and Satellites in Asheville, North Carolina, a contributor to the 224-page report, said the scientists who wrote it had sought, among other things, to draw attention to 10 variables he said "most intuitively" reflect temperature. He called that part of the report a "response" to allegations in recent months that scientists at the Climatic Research Unit at the University of East Anglia or NASA—or both—could jigger the record to fake warming, particularly by purportedly skewing records of land surface temperature. From the report:
If the land surface records were systematically flawed and the globe had not really warmed, then it would be almost impossible to explain the concurrent changes in this wide range of indicators produced by many independent groups.
What follows are the 10 variables that show warming, according to the report:
Air Temperature Near Earth's Surface: The 1960s and 1970s were cooler than the 2000s by about 0.6°C, the 1980s cooler by about 0.35°C, and the 1990s cooler by 0.2°C. Seven sets of data were used to come to that conclusion, with some of the same raw data in several of those sets (p. 28).
Humidity: A warmer atmosphere means a moister one, and three sets of data each show a steady rise since 1970, with peaks in "1987/88, 1997/98, 2002, 2006/07, and 2009 (/10)" (p. 31).
Glaciers: A negative "mass balance" means that glaciers lost more mass than they gained; 2008 was the 18th straight year this number was negative for the world's alpine glaciers. For example, the report says "of 93 Austrian glaciers surveyed in 2009, 85 receded, 7 were stationary, and 1 advanced"; most glaciers receded by more than 14 meters in 2009, "slightly higher than in 2008" (p. 47).
Meanwhile, the "34 widest marine-terminating glaciers in Greenland lost 101 km2 ice area in 2009" (p. 107). Meanwhile, Antarctica's climate has largely warmed in the past year-although "significant ice loss has occurred along the Antarctic Peninsula and West Antarctica in the last decade." Scientists cannot link the loss to regional warming (p. 126) but say warmer seas may be the culprit.
Snow Cover: Each decade since 1970, the extent of spring snow cover in the Northern Hemisphere has fallen more and more below the 40-year average. Winter snow cover fell in the 1980s and 1990s but rose slightly in the 2000s (p. 34).
Temperatures Over Oceans: Analysis of five sets of data shows that the air temperatures over the world's seas have risen steadily since 1970 (p. 26).
Temperatures Over Land: Four sets of data show the same trend, with slightly less warming in the past few years (p. 26).
Ocean Temperatures: The water temperature at the surface of the ocean has risen more or less steadily since roughly the 1980s. Compared with the 1971-2000 average, 2009 was the fourth warmest year for sea temperatures, "behind 1998, 2003, and 2005, the top three warmest [ocean temperature] years since 1950" (p. 55).
Sea Level: Since 2003, seas have risen by 2 to 3 mm a year (p. 71).
Sea Ice: The total area in Arctic seas covered by floating ice has dropped by roughly 4% per year; around Antarctica, sea ice has increased by roughly 1% per decade (details here).
Ocean Heat Content: The stored heat in the world's seas has risen steeply since roughly 1990, according to three separate data sets (p. 58).
*This item has been corrected. Peter Stott of the U.K. Met Office was originally cited as the speaker in a phone interview in the first paragraph instead of Peter Thorne of the Cooperative Institute for Climate and Satellites.