In a recent interview with CNBC, Environmental Protection Agency Administrator Scott Pruitt denied that carbon dioxide is a primary contributor to climate change. When asked if he believed whether it has been proven that CO2 is the primary control knob for climate, Pruitt responded:
No, I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact, so no, I would not agree that it’s a primary contributor to the global warming that we see.
Pruitt’s response is startling in its inaccuracy. In fact, there is not tremendous disagreement over whether the climate is changing, whether human activity is the cause of climate change, or the degree of impact CO2 is having on Earth’s climate. According to NASA:
Multiple studies published in peer-reviewed scientific journals show that 97 percent or more of actively publishing climate scientists agree: Climate-warming trends over the past century are extremely likely due to human activities.
It is clear from extensive scientific evidence that the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases, including carbon dioxide (CO2), chlorofluorocarbons, methane, and nitrous oxide. The most important of these over the long term is CO2, whose concentration in the atmosphere is rising principally as a result of fossil-fuel combustion and deforestation.
(Citing exhaustive evidence of human-induced climate change is beyond the scope of this article, but NASA’s Global Climate Change site is a good place to start.)
President Donald Trump does not believe in human-induced global warming, or in global warming in general: