20C3M: CMIP collecting data from 20th century coupled model simulations

Many modelling groups have completed or are in the process of performing simulations of the 20th century with ocean-atmosphere general circulation models. The simulations are driven with various combinations of external climate forcings, such as anthropogenic increases in greenhouse gases and sulphate aerosols, changes in solar radiation and forcing by explosive volcanism; and the different forcings are incorporated either into separate simulations or combined. These simulations have proven to be very valuable for our understanding of 20th century climate change (see, Figure 1; Stott et al., 2000; Meehl et al., 2003).