Is dark money boosting Bernie Sanders?

Bernie Sanders may decry how big money influences political elections, but that isn’t stopping groups independent of the Democratic presidential candidate from spending significant cash in his name.

The latest organization to do so: Friends of the Earth Action.

The national environmental nonprofit this week released an ad that praises Sanders’ green record and highlights his early opposition to the Keystone XL pipeline.

Friends of the Earth Action says it “provides extra political muscle” to sister group Friends of the Earth, a 501(c)(3) nonprofit founded in 1969 that “urge[s] policymakers to defend the environment and work towards a healthy environment for all people,” according to its website.

This is not Friends of the Earth Action’s first time entering the political arena. In 2008, for example, Friends of the Earth Action spent more than $70,000 in support of Democrat John Edwards’ failed presidential run.

The Sanders ad blitz is twofold, Pica said. He sees Sanders as more committed than Clinton to environmental issues and wants to force a conversation on climate change — a topic that has yet to be robustly discussed in debates.

Pica has, perhaps, already seen a measure of success: Sanders on Wednesday released a statement addressing a new report confirming 2015 was the hottest year in recorded history.

“Unless we get our act together, we will see in years to come more droughts, more floods and more extreme weather disturbances,” Sanders said in the statement.

Pica is helping lead the ad blitz. Canal Partners Media placed the ad, according to Federal Election Commission records. The media buying group regularly places ads for Democratic parties, movements and candidates.

When it comes to their donors, social welfare nonprofits can be — and often are — opaque.

But heeding Sanders’ money-in-politics gospel, Pica is promising transparency. Friends of the Earth Action, he says, will disclose within 24 hours on its website every donor who contributes more than $200. This aligns with the level of disclosure federal law requires traditional political action committees, super PACs and political parties.

This week’s ad flurry was purchased with existing funds, Pica said.

Normally, Friends of the Earth only partially discloses its donors and has accepted anonymous contributions when donors request anonymity. At the same time, the group fought for more political disclosure in Minnesota, where legislators introduced a bill in 2014 to tighten campaign finance rules.

Friends of the Earth Action paid about $20,000 to produce and air the ads, according to FEC documents. This is the first expenditure the group has made in any federal election this cycle — presidential or congressional — records show.

Friends of the Earth Action will continue to support Sanders, Pica said, and he left open the possibility of additional pro-Sanders ad campaigns.

“What we’ve done is a really modest buy,” Pica said. “He needs people to stand up, take action and contribute.” The group’s ad campaign presents a problem for Sanders, at least to some degree: As much as Sanders says he doesn’t have, want or need a super PAC, he has little control over the matter.

Beside Friends of the Earth Action, a super PAC funded by the union National Nurses United for Patient Protection is spending significant sums to promote his candidacy, unleashing $2 million on his behalf since the start of the election, according to the Center for Responsive Politics. The group has mostly paid for mailers and has yet to make its debut on the airwaves.

Then there’s Americans Socially United, a pro-Sanders super PAC run by Cary Lee Peterson, who has a long history of legal problems. The super PAC even duped Daniel Craig of James Bond fame into making a contribution.

Although the Sanders campaign sent a cease-and-desist order to Peterson, it had minimal effect, and the campaign has done comparatively little to rein in Friends of the Earth Action or National Nurses United for Patient Protection’s super PAC.

Officials from both groups say their pro-Sanders campaigns were started independent of him and his current and former campaign staffers.

Many super PACs supporting specific presidential candidates, such as the pro–Jeb Bush Right to Rise USA and the pro-Clinton Priorities USA Action, are led by close friends and political allies of the candidates being supported.

This presidential election, dark money groups supporting Republicans have so far outspent those supporting Democrats. Conservative Solutions Project, a 501(c)(4) nonprofit, has spent millions of dollars boosting Sen. Marco Rubio of Florida.

The Sanders campaign did not respond to requests for comment, but in an interview with CNN, Sanders spokesman Michael Briggs differentiated Friends of the Earth Action from other outside groups infusing the presidential election with money.

“Friends of the Earth Action is not a corporation looking to gut regulations or procure tax breaks,” Briggs said. “They are an organization made up of thousands of American citizens concerned about a healthy environment and fighting climate change.”

This story is from the Center for Public Integrity, a nonprofit, nonpartisan investigative media organization in Washington, D.C. Read more of its investigations on the influence of money in politics or follow it on Twitter.