Greenhouse Gases and Sulfate Aerosols

Climate models are often used to simulate future climates assuming specific
changes in our environment. Predicted global temperature changes are shown by
computing the effects of expected increased atmospheric levels of
carbon-dioxide and sulfate aerosols. This simulation estimates potential global
change using a coupled climate model that has interactive atmosphere, ocean,
land, and sea ice components.

A control climate was established by running the model for over 70 years with
solar forcing and greenhouse gases held at present day levels. Two additional
experiments were then performed, one of which has expected increases in
greenhouse gases, such as carbon dioxide, and another, in which the additional
effects of sulfate aerosols are included.

The differences from the control for a running average of the Dec/Jan/Feb
surface air temperature are shown in the next sequences which span over 70
years into the future. Note that some regions experience cooling relative to
the control experiment, and other areas have less warming than with increasing
greenhouse gases alone.

Temperature and albedo differences are represented as shown below for a running
average of the means of Dec/Jan/Feb.