Despite occurring during a period of low solar activity and a cooling la Ninã, last year’s global average surface temperature made 2011 the ninth warmest of the past 130 years, according to analyses released Thursday by NASA’s Goddard Institute for Space Studies (GISS).
Nine of the 10 warmest years on record have now occurred since 2000, and although 2011 was 0.22 degrees F (0.12 C) cooler than 2010, last year was the warmest in the presence of a cooling, la Ninã event.
Observable trends occurring over decades, rather than individual year-to-year variations, are what fuel concerns over global warming, and 2011 fits the long-term warming trend that has been occuring since the Industrial Revolution. Last year’s average global temperature was 0.92 degrees F (0.51 C) warmer than the mid-20th century baseline.
Annual variations and the long-term warming trend are illustrated in the NASA GISS animation below, which covers global temperatures during the period 1880-2011.
Reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average. (Data: NASA Goddard Institute for Space Studies. Visualization: NASA Goddard Space Flight Center Scientific Visualization Studio).
