So far, no hard evidence has emerged that says Donald Trump knowingly colluded with Russia during the 2016 campaign.

But there is plenty of evidence in the form of a tangible money trail that links Vladimir Putin’s Russian government with U.S. environmental groups. In fact, the source of this funding has been subject of two congressional committee inquiries. Most recently, Rep. Lamar Smith, R-Texas, who chairs the House Science, Space, and Technology Committee, released a report in March that explores Russia’s motives for disrupting America’s energy sector.

“Russia benefits from stirring up controversy about U.S. energy production,” Smith said in a press release. “U.S. energy exports to European countries are increasing, which means they will have less reason to rely upon Russia for their energy needs. This, in turn, will reduce Russia’s influence on Europe to Russia’s detriment and Europe’s benefit. That’s why Russian agents attempted to manipulate Americans’ opinions about pipelines, fossil fuels, fracking and climate change. The American people deserve to know if what they see on social media is the creation of a foreign power seeking to undermine our domestic energy policy.”

Smith’s report describes the Russian scheme to use nonprofit entities to influence and sway U.S. public policy and public opinion against fracking. The evidence in the report shows that Russia has been using U.S. environmental groups to spread what Smith aptly describes as “propaganda” to undermine America’s natural gas revolution.

So why isn’t President Trump tweeting about Russian interference with American energy and with natural gas development in particular?

Where energy policy is concerned, the media narrative against the Trump campaign never any made sense. Why would the Russians prefer Trump over Hillary Clinton given Trump’s commitment to natural gas development?

I’ll be speaking this week at the Kentucky Oil and Gas Association’s annual meeting in Louisville on this very topic and raising these very questions. Here’s some additional information I’ve uncovered with regard to the Sea Change Foundation, the San Francisco-based group that congressional investigators have identified as the major conduit of Russian funding.

What do we know about Sea Change, the purpose and origins of its funding, and what it means for public policy in the U.S.?

This organization has given out about $400 million between 2007 and 2015; yet it continues to operate in the shadows. For the record, I have tried contacting Sea Change officials several times to get its side of the story. They have decided to run silent.

Here's what I know from 990 tax forms.

Nat Simons, who founded Sea Change with his wife Laura Baxter-Simons, is vice chairman and director of Renaissance Technologies, the hedge fund founded by his father Jim Simons. Renaissance-affiliated firms and other Simons family entities have been domiciled in Bermuda with the assistance of several law firms.

Much of Sea Change’s funding in the 2006-2012 period came from the Simons family, which operates three other charitable foundations outside of Sea Change. The Simons family uses at least three firms for offshoring of its corporate and foundation assets: Wakefield Quin, Appleby Ltd., and Estera Services.

As I’ve reported before , Sea Change Foundation has donated to several environmental groups that have worked to block fracking and pipeline construction that make natural gas development and distribution possible. Some of the Sea Change recipients that have not received as much attention before are the Tides Foundation, which received $8 million from Sea Change making it the 12 th largest grantee in total funds received. The donations to Tides came within a three-year period from 2009-2011.

There is also the U.S. Climate Action Network, which received more than $7.3 million from Sea Change since 2009. The U.S. Climate Action Network formed in 1989 and is part of worldwide network of NGO’s called the Climate Action Network.

There’s another key player here called the Southern Alliance for Clean Energy, which is widely known as SACE and is based in Tennessee. A fellow named Stephen Smith who previously sat on the board of directors for the U.S. Climate Action Network for about 10 years currently serves as the executive director for SACE.

There are all kinds of interlocking relationships that speak to the importance of SACE and the role it plays in anti-energy activism. There are, for instance, vast sums of money that flow out of the Sea Change Foundation and back into SACE through environmental clearinghouses that make it possible for overseas entities to make indirect contributions to the U.S. environmental movement.

A large portion of SACE’s budget comes from the San Francisco-based Energy Foundation, which has received more than $30 million from Sea Change in the period from 2011 to 2012. In fact, the Energy Foundation is the biggest grantee of Sea Change both in terms of overall figures since 2008 and within the period around the time of the Klein transaction. SACE also lists the Tides Foundation as a supporter in its 2010-2011 annual report.

Cleary, these relationships deserve more scrutiny. If Congress moves forward with current legislative proposals to strengthen the Foreign Agents Registration Act, green groups may be required to disclose their foreign connections. These reforms are the subject of a previous post.

That and more scrutiny over the Russian ties with U.S. environmental groups would help. The media and the executive branch need to start investigating.

Kevin Mooney (@KevinMooneyDC) is a contributor to the Washington Examiner's Beltway Confidential blog. He is an investigative reporter in Washington, D.C. who writes for several national publications.