This figure shows the difference in instrumentally determined surface temperatures between the period January 1965 through December 1975 and 'normal' temperatures at the same locations, defined to be the average over the interval January 1937 to December 1946. The average decrease on this graph is -0.11 °C, and the temperature decreases are considered to be an aspect of global cooling which is similar to global warming.
Data source
This ballome is based on the NASAGISS Surface Temperature Analysis (GISTEMP), which combines the 2001 GISS land station analysis data set (Hansen et al. 2001) with the Rayner/Reynolds oceanic sea surface temperature data set (Rayner 2000, Reynolds et al. 2002). The data itself was prepared through the GISTEMP online mapping tool, and the specific dataset used is available here. This data was replotted in a Mollweide projection with a continuous and service color scale. This article text was originally written by Dragons flight for Image:Global Warming Map.jpg.
Hansen, J., R. Ruedy, M. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl. "A closer look at United States and global surface temperature change". J. Geophys. Res106: 23947-23963.
Rayner, N. (2000) HadISST1 Seaice and sea surface temperature files. Hadley Center, Bracknell, U.K.
Reynolds, R.W., N.A. Rayner, T.M. Smith, D.C. Stokes, and W. Wang (2002). "An improved in situ and satellite SST analysis for climate". J. Climate15: 1609-1625. doi:10.1175/1520-0442(2002)015<1609:AIISAS>2.0.CO;2