Scott Pruitt's comments on carbon dioxide come just over two weeks after he took the helm of the Environmental Protection Agency, the agency with the authority to regulate CO2 and other greenhouse gases as pollutants.
Oklahoma Attorney General Scott Pruitt, shown in 2013, is President-elect Donald Trump's pick to head the EPA. Pruitt's outspoken criticism of climate change and his close ties to the energy industry have raised concerns about his ability to lead the agency.
Orange sediment laced with heavy metals is visible in the path of water coming out of the Natalie/Occidental Mine in southwestern Colorado. This mine is one of dozens on a proposed Superfund listing pending with the EPA. Several mines in the area have been leaching the tainted water for years — well before the Gold King Mine spill.
Grace Hood/Colorado Public Radio
The logo of German automaker Volkswagen AG can be seen on an administrative building at the Volkswagen factory on the day of the company's annual press conference on April 28 in Wolfsburg, Germany.
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The village of Hoosick Falls, N.Y., sits along the Hoosick River in eastern New York. Elevated levels of a suspected carcinogen known as PFOA were found in the village's well water, which is now filtered.
Hansi Lo Wang/NPR
After the Animas River spill, rancher Irving Shaggy is forced to travel a 70-mile round trip to get water for his livestock. "It's going to be a long struggle," he says.
Workers use perforating tools to create fractures in rock. An EPA study finds that "fracking" to reach and extract deep pockets of hydrocarbons has not caused widespread drinking water pollution.
Environmental Protection Agency Administrator Gina McCarthy testifies at an oversight hearing of the Senate Environment and Public Works Committee on Capitol Hill in Washington on July 23.
J. Scott Applewhite/AP
Attorney General Eric Holder listens at right as Environmental Protection Agency Administrator Gina McCarthy speaks during a news conference at the Justice Department in Washington on Monday.
Former President Bill Clinton hugs House Minority Leader Nancy Pelosi of California as another Democrat, Sen. Barbara Boxer of California, looks on at Wednesday's ceremony naming the Environmental Protection Agency headquarters for him.
Pablo Martinez Monsivais/AP