A leading environmentalist group discouraged efforts to bring federal racketeering charges against oil companies and groups they support for "denying" climate change, suggesting instead that proponents of the effort enlist state-level law enforcement officials, newly released emails show.

The Union of Concerned Scientists (UCS) told professors at George Mason University, a public university in Virginia, that their push to enlist Attorney General Loretta Lynch in a civil action against oil companies and policy groups to which they donate was not legally sound.

Instead, the group suggested pushing for charges against those companies at the state level. That strategy has been put into effect by attorneys general in 17 states, who are currently exploring racketeering charges against oil giant Exxon Mobil and nonprofit groups that disagree with Democratic environmental policies.

The UCS emails were among those shared exclusively with the Washington Free Beacon on Friday after a Virginia judge rejected George Mason’s attempts to seal the records pending litigation over an open records lawsuit brought by attorney Chris Horner.

Horner filed an open records request in September seeking emails to and from GMU climatologist Jagadish Shukla and Dr. Edward Maibach, who directs GMU’s Center for Climate Change Communication.

They sent a letter to Lynch and President Barack Obama asking them to explore civil racketeering charges against climate change "deniers" and their financial supporters. Lynch has since said that she instructed the FBI to explore the possibility of filing such charges.

According to emails released on Friday, UCS quickly rejected the idea, citing its apparent lack of legal merit.

"After taking a close look, we’ve decided to not pursue this opportunity with you," wrote Peter Frumhoff, director of climate policy at UCS, in an email to Maibach.

"In reaching out to climate scientists to sign on, we feel that we’d need to give them some firmer grounding for believing that a federal investigation under the RICO statute is warranted—enough that they’d be able to explain their rationale for singing on to reporters and others," Frumhoff wrote.

However, he added that UCS was pushing for Democratic officials at the state level to bring charges of their own.

"Just so you know, we’re also in the process of exploring other state-based approaches to holding fossil fuel companies legally accountable—we think there’ll likely be a strong basis for encouraging state (e.g. AG) action forward," Frumhoff wrote.

That strategy is now playing out in 17 states, where Democratic attorneys general have teamed up to bring racketeering charges against Exxon Mobil. The Competitive Enterprise Institute, a libertarian think tank, has also been subpoenaed by the AG of the U.S. Virgin Islands as part of the campaign.

As for the possibility of federal charges, Frumhoff declined to lend the names of UCS’s ranks of scientists to the effort.

"We don’t think that Sen. [Sheldon] Whitehouse’s [D., R.I.] call gives enough of a basis for scientists to sign on to this as a solid approach at this point," he added, referring to a Whitehouse op-ed pushing for RICO charges that inspired Maibach’s and Shukla’s letter.

That letter set off a firestorm after the Free Beacon reported that a now-defunct nonprofit run by Shukla and his wife, the Institute of Global Environment and Society, had received more than $63 million in federal taxpayer support since 2001, more than 98% of its revenue in that time.

Horner, who is also a senior legal fellow at CEI, sought records that he expected would show Shukla, Maibach, and other public university scientists working behind the scenes to advance the legal campaign against oil companies and groups that take policy positions contrary to those of the AGs going after Exxon.

GMU initially told Horner that there were no responsive documents to open records requests. But he received emails from requests filed with other state universities that included emails to or from Shukla and Maibach. He sued GMU to compel the release of those and other emails.

A Virginia court ruled last month that GMU did in fact withhold responsive documents, and ordered their release. The university is appealing that decision to the Virginia Supreme Court, and sought on Friday to prevent the documents’ release pending that appeal.

A judge in Richmond rejected that request on Friday, allowing the documents to be released. If the case does proceed to the Supreme Court, Virginia attorney general Mark Herring, who has joined in the state-level legal campaign against Exxon Mobil, will be the first official involved in that effort to attempt to prevent the release of documents pertaining to it.

The emails released on Friday show collaboration between Maibach and other groups that seemed eager to aide in the legal campaign against climate change "deniers."

Maibach enlisted the services of Jeff Nesbit, the executive director of environmentalist communications firm Climate Nexus, they show. Nesbitt advised Maibach and Shukla on media strategy and offered to help placing an op-ed on the RICO efforts with a friendly reporter at the Washington Post.

After the Free Beacon and others reported on Shukla’s receipt of government grant money, a reporter with Fox News emailed him with questions, emails show. Maibach asked whether he should respond. "I wouldn’t advise him to," Nesbitt wrote.

Maibach suggested an interview with Washington Post climate reporter Chris Mooney instead. "Ah, I like that," Nesbitt replied. "Drop Chris a note. Let me know if I can help—I can circle back with him."

The emails released on Friday also reveal communications with the group RepublicEN, a GOP-branded nonprofit run by former Rep. Bob Inglis (R., Ga.). The emails show Inglis advising Maibach on the letter to Obama and Lynch and an accompanying op-ed.

"The op-ed is good when coming from you," Inglis wrote in a September email to Maibach. "We would have made it sound like we were coming alongside the Rs to help them out."

Inglis suggested that Republican policymakers would not likely heed Maibach’s warnings about climate change, but that some of their donors might.

"You are on the scene schooling [Republicans] about the cliff that they are about to go over," Inglis wrote. "They won’t like being schooled, but their financial backers and the smart money may take your words to heart and reflect the warning back to the candidates."

However, Inglis also cautioned against the use of racketeering statutes to go after climate change dissenters.

"RICO is a sore subject and in the conservative mind it may be case in the milieu of enforcing politically correct discourse in the academy, a regulation of speech," Inglis warned.