The nation’s largest environmental organization called for an investigation into Environmental Protection Agency Administrator Scott Pruitt after his controversial comments about climate change. In a letter to the EPA’s Office of the Inspector General Tuesday, the Sierra Club asserted that Pruitt violated the agency’s Scientific Integrity Policy.

“We write to request an inquiry into Administrator Pruitt’s recent public statements contradicting the international scientific consensus on climate change, which violate the U.S. Environmental Protection Agency’s Scientific Integrity Policy,” the letter, written by the Sierra Club's senior attorney Elena Saxonhouse and chief climate counsel Joanna Spalding, said in part. “We respectfully urge you to investigate and remedy this violation as soon as possible to prevent further erosion of scientific integrity.”

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The request for an inquiry came after Pruitt shared some of his climate change views during an interview with CNBC earlier in March. The EPA administrator was asked whether he believed it was proven that carbon dioxide is the “primary control knob for climate change.”

GettyImages-643463870 EPA administrator Scott Pruitt addresses employees in Washington, D.C., Feb. 21, 2017. The Sierra Club wants an investigation into Pruitt's controversial comments about climate change. Photo: Getty Images

“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,” Pruitt responded. “So no, I would not agree that it’s a primary contributor to the global warming that we see. But we don’t know that yet…We need to continue the debate and continue the review and analysis.”

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The Sierra Club called the comments “not only erroneous, but…politically motivated,” citing Pruitt’s opposition to carbon dioxide regulation and donations to his campaign by the fossil fuel industry. As such, the organization contended, they violated the agency’s Scientific Integrity Policy, adopted in 2012 to ensure that scientific information was being communicated effectively to the media and public “uncompromised by political or other interference.”

The EPA, which Pruitt now leads, shares a different view of climate change than the administrator himself.

“It is extremely likely that human activities have been the dominant cause of global warming,” the EPA website reads.