Updated

President Obama's pronouncement Tuesday that the Keystone XL pipeline would only be approved if it produced no net change in greenhouse gas emissions was no surprise to Tom Steyer.

A few days earlier, the billionaire hedge fund manager -- and big Obama donor -- had warned the president not to "trade" action on greenhouse gases for approval of Keystone XL. The warning was delivered as Steyer launched a summer-long social media campaign "We Love Our Land," with a goal to kill Keystone and keep Canadian oil bottled up in the tar sands.

"We really cannot afford 40 to 50 years of development of a humongous oil reserve that's twice as bad -- soup to nuts -- as normal crude," Steyer told a gathering at the National Press Club.

But critics have accused Steyer of hypocrisy.

Twenty-seven years ago, he founded Farallon Capital, which built much of its wealth on shrewd investments in fossil fuels. Farallon made millions for its investors, and left Steyer with a net worth estimated by Forbes at $1.4 billion.

One of Farallon's biggest holdings is in U.S. pipeline company Kinder Morgan, which has plans to expand a major competitor to Keystone -- the TransMountain pipeline. It carries tar sands oil from Edmonton to British Columbia's west coast for export to Asia. If Kinder Morgan gets approval for the expansion, TransMountain would carry 900,000 barrels of tar sands oil every day.

That's more than Keystone XL.

Louisiana Sen. David Vitter -- a vocal proponent of Keystone -- accuses Steyer of having financial interest in the death of a pipeline he opposes on environmental grounds.

"I think it's hypocrisy, quite frankly," Vitter told Fox News. "Who knows when he's going to divest of these investments ... maybe in a few months when his helping kill Keystone will boost them up to top value. ... Who knows?"

Steyer stepped down as Farallon's CEO late last year to focus on political and environmental activism. While he continues to have significant investments with Farallon, according to a spokesman, Steyer has directed the fund to "green" his portfolio and divest him of all positions in oil and coal -- including Kinder Morgan.

It is unclear where he is in that process. According to Steyer spokesman Chris LeHane, "This divestment has been taking place consistent with the applicable legal requirements."

Keystone XL is one of three pipeline proposals to carry heavy bitumen crude from Canada's oil sands to market. The others are TransMountain and Northern Gateway, which would carry oil from Edmonton to Kitimat, British Columbia. It appears that Northern Gateway will not be approved. If Keystone XL is killed, it will leave TransMountain as the only game in town for transporting oil directly from the tar sands to export terminals. And most of that oil will head west to Asia.

Steyer makes the case that since the Northern Gateway pipeline likely won't be built, there is no "competitive" reason to build Keystone. He also argues that not building either will limit oil production in the tar sands and will effectively contain the production of greenhouse gases. But in making that argument, he curiously omits any mention of the TransMountain pipeline.

The Daily Caller's Michael Bastasch, who first illuminated Steyer's potential financial gain, says there's a lot of sleight-of-hand going on among Keystone's opponents.

"Not only does the oil industry stand to benefit -- which we all know if the Keystone pipeline gets approved," Bastasch told Fox News, "but there are people on the other side who stand to gain if the pipeline doesn't get approved. And that's something you don't hear about a lot."

Steyer and other environmentalists insist Keystone XL will dramatically increase the production of greenhouse gases.

Nebraska Rep. Lee Terry, though, says while tar sands oil is heavier than that from other sources, it would eliminate the need for some imports -- including heavy crude from Venezuela. He argues that building Keystone XL is in the strategic, security and economic interests of the United States.

"What's being killed is our access to the oil sands, which is the third-largest oil pool in the world," Terry told Fox News. "It would completely offset Venezuelan oil -- so it's our energy security, it's the jobs that would be created."

Canadian officials insist that the tar sands will be developed regardless of whether Keystone XL or Northern Gateway are built. There are plenty of ways, they say, to get oil to market.

Supporters of Keystone argue that those methods -- ship, rail and truck -- produce far more greenhouse gases than a pipeline ever would.