A Republican skeptic of climate science now wants to know if Russia is behind online opposition to fossil fuels

A top House Republican who’s long questioned the veracity of climate science is probing whether Russian agents are responsible for any anti-fossil-fuel advertisements on Facebook, Google and Twitter.

The concerns come in a new letter to those three tech giants, sent Tuesday, by Rep. Lamar Smith, the GOP lawmaker who chairs the House Science and Technology Committee. At a time when congressional investigators are studying the effect of Kremlin-backed social media ads during the 2016 presidential election, Smith wants to know if Russia placed similar ads to try to harm U.S. energy giants in recent months.

In Smith’s eyes, Russia aims “to suppress the widespread adoption of fracking in Europe and the U.S.” That’s a particular way of mining the earth for natural gas. But it’s a controversial one, pitting environmentalists against the likes of Smith, who’s focused some of his recent efforts on attacking climate scientists.

Nevertheless, Smith is still demanding that Alphabet, Facebook and Twitter brief him next month on the matter. And, in the meantime, he’s seeking “all documents and communications” related to potential Russian purchases of energy-related ads on their platforms.

Smith also includes a more audacious, broad-reaching ask in his letter: He’s demanding “all documents and communications referring or relating to the source of advertisements” on Alphabet, Facebook or Twitter “affiliated entities advocating for so-called green initiatives,” his letter notes.

“Social media platforms, such as Twitter and Facebook, have the ability to serve as an effective propaganda arm conveying specific messages to geographically targeted audiences,” Smith explained.

”The committee is concerned that divisive social and political messages conveyed through social media have negatively affected certain energy sectors,” he continued, “which can depress research and development in the fossil-fuel sector and the expanding potential for natural gas.”

For the moment, Facebook has acknowledged that Russian agents purchased ads — about 3,000 of them, totaling $100,000 — prior to the 2016 presidential election. Some of them sought to stoke social, religious and racial tensions, and at times, they touched on “topics from LGBT matters to race issues to immigration to gun rights,” the social giant has said.

But the two congressional panels investigating the matter — the House and Senate Intelligence Committees — have not yet reviewed copies of every ad in question, and Facebook is still searching for any potential, additional evidence, sources have told Recode. Twitter, for its part, is expected to address lawmakers’ questions about its own platform tomorrow morning.

Smith, meanwhile, offers no direct evidence that Russia did seek to destabilize U.S. energy giants. In his letter, though, he points to a report in the New York Times — from 2014 — that suggested Russian money helped fuel protests against U.S. energy giants that sought to expand their shale-drilling operations.

This article originally appeared on Recode.net.