Global Temperatures | City Temperatures | Ocean Overturning

NASA's analysis of Earth's surface temperature found that 2012 ranked as the ninth-warmest year since 1880. NASA scientists at the Goddard Institute for Space Studies (GISS) compare the average global temperature each year to the average from 1951 to 1980. This 30-year period provides a baseline from which to measure the warming Earth has experienced due to increasing atmospheric levels of heat-trapping greenhouse gases. While 2012 was the ninth-warmest year on record, all 10 of the warmest years in the GISS analysis have occurred since 1998, continuing a trend of temperatures well above the mid-20th century average. The record dates back to 1880 because that is when there were enough meteorological stations around the world to provide global temperature data. (NASA Press Release, 1/15/2013).

2012 annual mean global surface temperature anomaly (deviation from base period 1950-1980). Credit: NASA GISS, From NASA/NOAA Press Materials website.		2012 annual mean land and ocean temperature anomalies (deviations from base period 1951-1980). Credit NOAA NCDC. From NASA/NOAA Press Materials website.

According to the GISS analysis:

The average temperature in 2012 was about 58.3 degrees Fahrenheit (14.6 Celsius), which is 1.0 F (0.6 C) warmer than the mid-20th century baseline. The average global temperature has risen about 1.4 degrees F (0.8 C) since 1880, according to the new analysis.

"One more year of numbers isn't in itself significant," GISS climatologist Gavin Schmidt said. "What matters is this decade is warmer than the last decade, and that decade was warmer than the decade before."

Read the complete analysis and discussion from the NASA Research News: NASA Finds 2012 Sustained Long-Term Climate Warming Trend (January 15, 2013).
Also see "Five-year global temperature Anomalies from 1880-2012" including animation materials and frames (NASA GSFC).

Find more information (references and websites)

• NASA GISS Surface Temperature Analysis (GISTEMP)
• NASA GISS Global Temperature Annual Summations: 2012 | 2011 | 2010 | 2009, 2008, 2007, 2005, 2004, 2003, 2002, 2001
• NASA GISS Combined land-surface air and sea-surface water temperature anomalies (Land-Ocean Temperature Index, LOTI): Global-mean monthly, seasonal, and annual means, 1880-present, updated through most recent month