Figure 8. Model projections and observed changes in global average surface temperature following the June 1991 eruptions of Mt. Pinatubo relative to the global average temperature for the 3-month period April-June 1991. Values are 3-month running mean anomalies ( °C) ending with October-December 1994. [Source: J. Hansen, GISS; and Hadley Centre for Climate Prediction and Research, UK].