The EPA chief’s criticisms of climate models are without merit

During a TV appearance on Fox Business, U.S. Environmental Protection Agency chief Scott Pruitt acknowledged that human activity is causing climate change—but questioned the underlying scientific research as to how much it is contributing. “The modeling that has been used over the last several years has absolutely been questionable,” he said. Based on mathematical methods that simulate the earth’s complex systems, climate models are tested against real-world measurements and observations to verify their validity. They are then used to predict how the climate system will react to additional greenhouse gases in the future. According to Climate Communications, a nonprofit science and outreach project, “Far from overestimating future climate change, climate models are more likely to be conservative in their predictions.” One thing is certain: Unlike many of Pruitt's recent claims, some of these models measuring climate change are very accurate. But Pruitt’s critique boils down to his ideological skepticism. Comparing trends in solar radiation, scientists have concluded that the sun could not have caused the observed warming across the globe over the past 60 years without the help of greenhouse gases, which trap heat in our atmosphere. Thus, scientists are nearly unanimously certain that carbon pollution from the burning of fossil fuels is the principal cause of climate change.