Global Temperatures | City Temperatures | Ocean Overturning

Calendar year 2008 was the coolest year since 2000, according to the Goddard Institute for Space Studies analysis of surface air temperature measurements. In our analysis, 2008 is the ninth warmest year in the period of instrumental measurements, which extends back to 1880 (left panel below). The ten warmest years all occur within the 12-year period 1997-2008. The two-standard-deviation (95% confidence) uncertainty in comparing recent years is estimated as 0.05°C, so we can only conclude with confidence that 2008 was somewhere within the range from 7th to 10th warmest year in the record.

Annual-means of global-mean temperature anomaly. Click for PDF.		Global map of surface temperature anomalies, in degrees Celsius, for 2008. Click for PDF.

The Southern Oscillation and increasing green house gases continue to be, respectively, the dominant factors affecting interannual and decadal temperature change. Solar irradiance has a non-negligible effect on global temperature (see GISS discussion). Given our expectation of the next El Niño beginning in 2009 or 2010, it still seems likely that a new global temperature record will be set within the next 1-2 years, despite the moderate negative effect of the reduced solar irradiance.

The map of global temperature anomalies in 2008 (right panel above), shows that most of the world was either near normal or warmer than in the base period (1951-1980). Eurasia, the Arctic and the Antarctic Peninsula were exceptionally warm, while much of the Pacific Ocean was cooler than the long-term average. The relatively low temperature in the tropical Pacific was due to a strong La Niña that existed in the first half of the year. La Niña and El Niño are opposite phases of a natural oscillation of tropical temperatures, La Niña being the cool phase.

Complete analysis and discussion is available from: GISS Surface Temperature Analysis/Global Temperature Trends: 2008 Summation - Provided by NASA Goddard Institute for Space Studies (GISS)

Find more information (references and websites)

• NOAA: 2008 Global Temperature Ties as Eighth Warmest on Record based on the combined average of worldwide land and ocean surface temperatures through December
• NASA GISS Surface Temperature Analysis (GISTEMP)
• NASA GISS Global Temperature Annual Summations: 2008, 2007, 2005, 2004, 2003, 2002, 2001, 2000 (n/a), 1999, 1998, 1997, 1996