na = not available

^{†} Numbers in italics indicate simulations with other than a 1%/yr increase
in CO

_{2}.

* 1%/yr of current CO

_{2} concentrations.

^{1} Polar deep ocean quantities constrained.

^{2} Three additional 50-year runs, each from different initial conditions.

^{3} CO

_{2} from IPCC scenario 90A after greenhouse gas forcing from 1880 to
1990.

^{4} As (1) with a representation of aerosol forcing, with increases after
1990 based on IS92a.

^{5} Equilibrium model excluded sea ice dynamics. Coupled model has warmer
than observed tropical sea surface temperatures and a vigorous ice albedo
feedback (Washington and Meehl, 1996) contributing to the high sensitivity.

^{6} Average of three experiments from different initial conditions.

^{7} CO

_{2} increased by 1%/yr from 1990. Observed greenhouse gas forcing used
from 1860 to 1990.

^{8} As (7) with a representation of aerosol forcing, with increases of aerosol
and greenhouse gases after 1990 based on IS92a.