"The usual discussion is whether the climate model forecasts of Earth's climate 100 years or so into the future are realistic," said David Douglass of the University of Rochester, the study's lead author. "Here we have something more fundamental: Can the models accurately explain the climate from the recent past? It seems that the answer is no."

The study that included scientists from the University of Alabama-Huntsville and the University of Virginia compared the climate change "forecasts" with tropical temperature data collected by surface, satellite and balloon sensors. The models predicted the lower atmosphere should warm significantly more than it actually did.

"The last 25 years constitute a period of more complete and accurate observations and more realistic modeling efforts," said Fred Singer from the University of Virginia. "Nonetheless, the models are seen to disagree with the observations. We suggest, therefore, that projections of future climate based on these models should be viewed with much caution."

The study appeared in the online issue of the International Journal of Climatology.