Variations in surface air temperature for the last 1000 years, estimated from a variety of sources, including tree-growth indices and written records, largely from western Europe and eastern North America. Temperatures are shown as departures in degrees Celsius from the baseline value for 1900. Compiled by R. S. Bradley and J. A. Eddy, based on J. T. Houghton et al., Climate Change: The IPCC Assessment, Cambridge University Press, Cambridge, 1990 and published in EarthQuest, vol 5, no 1, 1991. Back