Global Temperature Update Through 2012 by J. Hansen, M. Sato, R. Ruedy (Jan 15 2013)
The original pdf document of this global temperature update, including an impressive set of graphics, is available here and also on Jim Hansens website: http://www.columbia.edu/~jeh1/
Global surface temperature in 2012 was +0.56°C (1°F) warmer than the 1951-1980 base period average, despite much of the year being affected by a strong La Nina. Global temperature thus continues at a high level that is sufficient to cause a substantial increase in the frequency of extreme warm anomalies. The 5-year mean global temperature has been flat for a decade, which we interpret as a combination of natural variability and a slowdown in the growth rate of the net climate forcing.
Frequency of occurrence of local June-July-August temperature anomalies (relative to 1951-1980 mean) for Northern Hemisphere land in units of local standard deviation (horizontal axis). Temperature anomalies in 1951-1980 match closely the normal distribution (green curve), which is used to define cold (blue), typical (white) and hot (red) seasons, each with probability 33.3%. Lower graphs use only a subset of stations (1886 of 6147) that were present throughout recent decades as well as the base period.
