Surface Temperatures

Figure 16 shows the surface-temperature change predicted by the models for January for an equilibrium climate with a doubled CO₂ atmosphere. Since a temperature difference is being plotted, a value of zero indicates the model calculates no change in surface temperature with a doubled CO₂ atmosphere. The GISS model gives very large values of warming for the enhanced greenhouse climate, with generally higher values at high latitudes. The GFDL model produces results that are less severe and more uniform over the domain. The OSU results also are less severe and do not have such large values at high latitudes. A common feature of all models is that they all agree that the result of increased CO₂ is to produce a warming that averages something on the order of about 4^o C.

The July calculations given in Figure 17 are similar to the previous results in that all models produce a pattern of warming. There is less evidence of severe warming at high latitudes in the July results, and there is somewhat better agreement among the models in the values produced. The GFDL model tends to produce higher temperature changes than the others.

PREVIOUS: Climate Change

NEXT: Precipitation