Global Temperatures | City Temperatures | Ocean Overturning

The year 2007 tied for second warmest in the period of instrumental data, behind the record warmth of 2005, in the Goddard Institute for Space Studies (GISS) analysis. 2007 tied 1998, which had leapt a remarkable 0.2°C above the prior record with the help of the "El Niño of the century". The unusual warmth in 2007 is noteworthy because it occurs at a time when solar irradiance is at a minimum and the equatorial Pacific Ocean is in the cool phase of its natural El Niño-La Niña cycle.

Annual surface temperature anomaly relative to 1951-1980 mean, based on surface air measurements at meteorological stations and ship and satellite measurements of sea surface temperature.		Global map of surface temperature anomalies for 2007.
(Click for a large GIF or PDF version of the images)

The Southern Oscillation and the solar cycle have significant effects on year-to-year global temperature change. Because both of these natural effects were in their cool phases in 2007, the unusual warmth of 2007 is all the more notable. It is apparent that there is no letup in the steep global warming trend of the past 30 years (see 5-year mean curve in the Figure above, left).

The map reveals that the greatest warming has been in the Arctic and neighboring high latitude regions. Polar amplification is an expected characteristic of global warming, as the loss of ice and snow engenders a positive feedback via increased absorption of sunlight. The large Arctic warm anomaly of 2007 is consistent with observed record low Arctic sea ice cover in September 2007.

Complete analysis and discussion is available from: GISS Surface Temperature Analysis/Global Temperature Trends: 2007 Summation - Provided by NASA Goddard Institute for Space Studies (GISS)

Find more information (references and websites)

• GISS Surface Temperature Analysis (GISTEMP)
• Global Temperature Annual Summations: 2005, 2004, 2003, 2002, 2001, 2000 (n/a), 1999, 1998, 1997, 1996