Figure 8.20: (a) Radiative
forcing (Wm-2) since 1979 due to changes in stratospheric aerosols, ozone, greenhouse
gases and solar irradiance.
(b) to (d) Observed global annual mean surface, tropospheric and stratospheric
temperature changes and GISS GCM simulations as the successive radiative forcings
are cumulatively added one by one. An additional constant 0.65 Wm-2 forcing was
included in all their simulations, representing the estimated disequilibrium forcing
for 1979. The base period defining the zero mean observed temperature was 1979
to 1990 for the surface and the troposphere and 1984 to 1990 for the stratosphere.
Taken from Hansen et al. (1997).
