William W. Kellogg's graph from 1977 shows the estimates of past and future variations of global mean temperature from 1850 until 2050. This is a particularly interesting projection because...

Source:

WMO Report 1977: Kellogg, William W. "Effects of Human Activities on Global Climate. A summery, with consideration of the implication of a possibly warmer Earth", WMO Technical Note 156. Geneva: World Meteorological Organization, p. 24.