Study: Climate Predictions Wildly Overestimated Global Warming

A new study has found that climate predictions used by scientists, forecasters, and academics have wildly overestimated global warming, forecasting on average two times more warming than actually occurred. 

As Fox News reports, a study in the science journal Nature Climate Change “compared 117 climate predictions made in the 1990s to the actual amount of warming.” And out of those 117 predictions, according to the study’s author, “three were roughly accurate and 114 overestimated the amount of warming. On average, the predictions forecasted two times more global warming than actually occurred.”

John Christy, a professor at the University of Alabama in Huntsville, told Fox News that he “looked at 73 climate models going back to 1979 and every single one predicted more warming than happened in the real world.”

Many of these “overestimations also made their way into the popular press.” For instance, the Associated Press in 1989 reported, “Using computer models, researchers concluded that global warming would raise average annual temperatures nationwide 2 degrees by 2010.” Such articles then became the launching point for many other stories in local papers and national newscasts. According to NASA, though, “global temperature has increased by less than half that–about 0.7 degrees Fahrenheit–from 1989 to 2010.”

“I think in one sense the climate establishment is embarrassed by this, and so they’re trying to minimize the problem,” Christy said. “The fundamental thing a climate model is supposed to predict is temperature. And yet it gets that wrong.”

According to the study’s authors, the models could have been off for many reasons, including “solar irradiation and incorrect assumptions about the number of volcanic eruptions to bad estimates about how CO2 effects cloud patterns.” Another factor may have been the models overestimated global warming “because of the way they handle clouds,” according to Christy.