Temperatures in the past century

Abstract

Data on near-surface air temperatures are available at a number of sites dating back about 100 years in some cases. Meteorological scientists have methodically examined these data and derived the best overall data sets that the data allow (Hansen et al., 1999, 2001; Pielke et al., 2007a; CCSP, 2005; and Brohan et al., 2006). NASA’s Goddard Institute for Space Studies (GISS), under leadership of James Hansen, has analyzed U.S. and world temperature patterns since about 1880 in great detail (Hansen et al., 1999, 2001; Brohan et al., 2006). Studies of temperature change over land areas are routinely made by several groups based on measurements of the meteorological station network. It is beneficial to estimate global temperature change from both the meteorological station data alone, and a combined analysis with ocean data, because the land and ocean data have their own measurement characteristics and uncertainties.