Nailed It: Early Climate Models Have Accurately Predicted Effects of Global Warming, Study Finds

Ron BrackettPublished: December 5, 2019

This color-coded map shows global surface temperature anomalies. Higher-than-normal temperatures are shown in red, and lower-than-normal temperatures are shown in blue.

The computer models used over the past five decades to predict the impact of future global warming have turned out to be very accurate so far, a new study has found.

Climate scientists at the University of California, Berkeley, Massachusetts Institute of Technology and NASA evaluated climate models from the early 1970s into the late 2000s to see how well they predicted the actual global mean surface temperature, based on levels of carbon dioxide and other greenhouse gases.

They also looked at how well the models matched the relationship between warming and changes in levels of greenhouse gases.

Of the 17 climate projections examined, 14 effectively matched observations after they were published, according to the study published Wednesday in the journal Geophysical Research Letters.

(MORE: Global Greenhouse Gas Emissions Projected to Set Another Record This Year)

Estimating how much greenhouse gas will be emitted in the future is difficult because it involves human behavior, how well the economy is doing and government policy. Rolling back emission regulations on new cars, for example, adds more carbon dioxide to the atmosphere.

"We did not focus on how well their crystal ball predicted future emissions of greenhouse gases, because that is a question for economists and energy modelers, not climate scientists," Zeke Hausfather, a UC Berkeley doctoral student and lead author of the study, said in a news release. "It is impossible to know exactly what human emissions will be in the future. Physics we can understand, it is a deterministic system; Future emissions depend on human systems, which are not necessarily deterministic."

So, according to Gizmodo's Earther blog, the researchers put the actual amount of global greenhouse emissions into the models to see if they would accurately predict global temperature rise since the models were created.

That found the models were quite accurate.

"The earliest models were so skillful because the fundamental science behind the greenhouse effect and global warming is well established and fairly straightforward," Henri Drake, a co-author of the study and an MIT doctoral student, told Mashable.

"The real message is that the warming we have experienced is pretty much exactly what climate models predicted it would be as much as 30 years ago," Hausfather said. "This really gives us more confidence that today's models are getting things largely right as well."

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The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.