The EPA's Scientific Integrity Committee convened a review panel to look into Pruitt's comment following the Sierra Club's complaint.
The panel concluded that Pruitt did not violate the Scientific Integrity Policy because it "explicitly protects differing opinions," according to a draft letter to the Sierra Club from the panel. The draft was obtained by conservative media outlets including the Washington Examiner and Washington Free Beacon.
"In his response, the Administrator expressed his opinion regarding contributors to global warming and called for more debate, review, and analysis as a precursor to any future EPA policy decision on the matter," wrote Thomas H. Sinks, Jr., director of the EPA's Office of the Science Advisor, in the letter.
The EPA confirmed the panel's conclusion in a statement to CNBC.
"In its findings, the Panel stated that an Agency employee is free to express his or her opinion on the science. The Panel also stated that this is a fundamental principle to EPA's Scientific Integrity Policy even (and especially) when that point of view might be controversial. This protection is afforded to any employee including the Administrator," said Megan Maguire, an EPA science communications specialist.
Elena Saxonhouse, a senior attorney for Sierra Club, said in a statement that the decision lets Pruitt off the hook for deceiving the American public in high-profile contexts.
"Pruitt's statements on CNBC were not merely a scientific 'opinion', as EPA's letter suggests," Saxonhouse said. "With his many close ties to the fossil fuel industry, it is clear they were a politically motivated attempt to obfuscate basic facts that EPA scientists have studied and verified for years."
The Sierra Club noted in the release that it did not receive the letter from the EPA until Wednesday, one day after the Examiner and Free Beacon ran their stories. It alleged that the EPA press staff leaked the document to the conservative-leaning papers. An EPA spokesperson declined to comment on the record.
On Tuesday, the EPA press office emailed a copy of the Free Beacon article containing a link to the panel's letter to some reporters, according to a copy of the email reviewed by CNBC. An EPA spokesperson, Jahan Wilcox, retweeted the Washington Examiner story shortly after it came out.
In March, the Sierra Club contended that while Pruitt is within his rights to advocate for policy changes, he is not allowed to distort the basic science that underpins policies he opposes. It said the comment contradicted decades of established science and violated three principles of the EPA's Scientific Integrity Policy, including:
- "When dealing with science, it is the responsibility of every EPA employee to conduct, utilize, and communicate science with honesty, integrity, and transparency, both within and outside the Agency."
- "[P]olicy makers shall not knowingly misrepresent, exaggerate, or downplay areas of scientific uncertainty associated with policy decisions."
- "To operate an effective science and regulatory agency like the EPA, it is also essential that political or other officials not suppress or alter scientific findings."
The overwhelming majority of climate scientists — as much as 97 percent of the community — has concluded that carbon dioxide emissions from human activity is the primary cause of global warming.
Pruitt rose to prominence as Oklahoma's attorney general, where he fought alongside fossil fuel companies and other Republican attorneys general to overturn Obama-era energy regulations. As EPA chief, he has been instrumental to President Donald Trump's effort to roll back those rules, and was a primary proponent for the United States leaving the Paris climate agreement.