FIGURE 7-1 (A) Glacier-length-based temperature reconstruction for various regions. The black curve shows an estimated global mean value, obtained by giving weights of 0.5 to the Southern Hemisphere, 0.1 to Northwest America, 0.15 to the Atlantic sector, 0.1 to the Alps, and 0.15 to Asia. (B) Best estimate of the global mean temperature, obtained by combining the weighted global mean temperature for 1834–1990 with the average of temperature records at earlier times. The band indicates the estimated standard deviation. SOURCE: Oerlemans (2005a). Reprinted with permission from AAAS; copyright 2005.