This figure shows the predicted distribution of temperature change due to global warming from the Hadley Centre HadCM3 climate model. These changes are based on the IS92a ("business as usual") projections of carbon dioxide and other greenhouse gas emissions during the next century, and essentially assume normal levels of economic growth and no significant steps are taken to combat global greenhouse gas emissions.
The plotted gray tints show predicted surface temperature changes expressed as the average prediction for 2070-2100 relative to the model’s baseline temperatures in 1960-90. The average change is 3.0 degrees C, placing this model on the lower half of the Intergovernmental Panel on Climate Change’s 1.4-5.8 degrees C predicted climate change from 1990 to 2100. As can be expected from their lower specific heat, continents are expected to warm more rapidly than oceans with an average of 4.2 degrees C and 2.5 degrees C in this model, respectively. The lowest predicted warming is 0.55 degrees C south of South America and the highest is 9.2 degrees C in the Arctic Ocean (points exceeding 8 degrees C are plotted as black).
This model is fairly homogeneous except for strong warming around the Arctic Ocean related to melting sea ice and strong warming in South America related to predicted changes in the El Nino cycle and Brazillian rainforest. This pattern is not a universal feature of models, as other models can produce large variations in other regions (e.g., Africa and India) and less extreme changes in places like South America.
