This still image from an animation shows the temperature
anomalies that were present during 2007. Note the Arctic.
Source: NASA GISS
With January’s chill comes the season of the annual temperature scorecards for the home planet. Both the NASA Goddard Institute for Space Studies and the National Climate Data Center say 2007 delivered some of the warmest average temperatures on record for the globe and United States. Each agency produced slightly different results.
Was 2007 the second warmest year on record? Or the fifth? And what about the United States?
Here’s one answer, from the NCDC:
The average U.S. temperature for 2007 was 54.2 °F; 1.4 °F warmer than the 20th century mean of 52.8 °F. NCDC originally estimated in mid-December that 2007 would end as the eighth warmest on record, but below-average temperatures in areas of the country last month lowered the annual ranking.
For Alaska, 2007 was the 15th warmest year since statewide records began in 1918.
One thing’s for sure. The trend line has continued to lurch upward. For up, and for those of us at the high latitudes, where the sun never abandons June yet hardly shines in December, 2007 clearly was another sign that climate change continues its acceleration.
From the GISS story:
The greatest warming in 2007 occurred in the Arctic, and neighboring high latitude regions. Global warming has a larger affect in polar areas, as the loss of snow and ice leads to more open water, which absorbs more sunlight and warmth.
Snow and ice reflect sunlight; when they disappear, so too does their ability to deflect warming rays. The large Arctic warm anomaly of 2007 is consistent with observations of record low geographic extent of Arctic sea ice in September 2007.