Model Behavior

How well have previous IPCC reports predicted the future? Pretty well, concludes an international team of scientists who compared actual observations of carbon dioxide, temperature and sea level from 1990 to 2006 to the IPCC's projected changes for the same period. Their results have appeared in the peer-reviewed journal Science.

According to this release from the Commonwealth Scientific and Industrial Research Organisation in Australia,

the authors found that carbon dioxide concentration followed the modeled scenarios almost exactly, that global-mean surface temperatures were in the upper part of the range projected by the IPCC, and that observed sea level has been rising faster than the models had projected and closely followed the IPCC Third Assessment Report upper limit of an 88 cm rise between 1990 and 2100.

In other words, "previous projections have not exaggerated the rate of change but may in some respects have underestimated it."