In an interview on CNBC, Energy Secretary Rick Perry said carbon dioxide is not “the primary control knob” for the Earth’s temperature and climate. But scientists say it’s “extremely likely” that human activity — primarily CO2 emissions — is the main cause of global warming.
Perry made his claim during an interview with Joe Kernen on CNBC.
Kernen, June 19: Do you believe CO2 is the primary control knob for the temperature of the Earth and for, for the climate?
Perry: No, most likely the primary control knob is the ocean waters and this environment that we live in.
Perry is not the first member of the Trump administration to make this claim. Back in March, Environmental Protection Agency head Scott Pruitt said, “I would not agree that [CO2 is] a primary contributor to the, to the global warming that we see.”
But as we have written time and again, the U.N.’s Intergovernmental Panel on Climate Change’s fifth assessment report says it’s “extremely likely” (at least 95 percent probable) that more than half of the observed temperature increase since the mid-20th century is due to human, or anthropogenic, activity.
What does “human activity” entail? The IPCC sums it up like this:
IPCC, 2014: Anthropogenic greenhouse gas emissions have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of carbon dioxide, methane and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.
The report adds, “Emissions of CO2 from fossil fuel combustion and industrial processes contributed about 78% of the total GHG emissions increase from 1970 to 2010.”
This means that, among all of the human activities that contribute to global warming, emitting CO2 makes the largest contribution. Still, there are other drivers, such as deforestation, the decomposition of wastes in landfills and agriculture.
What about the oceans’ role in global warming? Perry got it backward.
The oceans play a “central role in stabilizing Earth’s climate system” by storing and releasing heat over long periods of time, explains the National Oceanic and Atmospheric Administration. And the oceans have stored the majority of the excess heat trapped by increased greenhouse gases in the atmosphere due to human activities.
But this “heat energy eventually re-enters the rest of the Earth system by melting ice shelves, evaporating water, or directly reheating the atmosphere,” adds NOAA. “Thus, heat energy in the ocean can warm the planet for decades after it was absorbed.”
In other words, “Though the atmosphere has been spared from the full extent of global warming for now, heat already stored in the ocean will eventually be released, committing Earth to additional warming in the future,” says NOAA.
One last point: Perry also said, “Are we going to continue to have innovation that helps to effect in a positive way our environment? Absolutely,” adding, “I’m excited about what we’re going to see coming out of our national labs, coming out of the private sector, working in concert with private, or I should say, public and private sector opportunities.”
But under Trump’s proposed budget, the Department of Energy’s Office of Science would lose $900 million of its roughly $5 billion budget — an 18 percent decrease. That office funds research at more than 300 universities and institutes, as well as 10 of the DOE’s 17 national labs, according to the department’s website.
So it’s unclear at this point how much the public sector will be able to contribute to innovation compared with past years.
Editor’s Note: SciCheck is made possible by a grant from the Stanton Foundation.