Even 50-year-old climate models correctly predicted global warming

Sciencemag.org  December 2019

Climate change doubters have a favorite target: climate models. They claim that computer simulations conducted decades ago didn’t accurately predict current warming, so the public should be wary of the predictive power of newer models. Now, the most sweeping evaluation of these older models—some half a century old—shows most of them were indeed accurate.

“How much warming we are having today is pretty much right on where models have predicted,” says the study’s lead author, Zeke Hausfather, a graduate student at the University of California, Berkeley.

Climate scientists first began to use computers to predict future global temperatures in the early 1970s. That’s when newfound computing power coincided with a growing realization that rising carbon dioxide levels could boost global temperatures. As the issue gained public attention, critics questioned the reliability of rudimentary model predictions. Even a 1989 news article in Science radiated skepticism, stating that “climatologists may have a gut feeling that the greenhouse effect is heating up the Earth, but they have not been close to proving it.”….

The new findings echo what many in the climate science world already know, says Piers Forster, an expert in climate modeling at the United Kingdom’s University of Leeds. Still, he says, “It’s nice to see it confirmed.”

Forster notes that even today’s computer programs have some uncertainties. But, “We know enough to trust our climate models” and their message that urgent action is needed, he says.