President Barack Obama is approaching two of the most crucial energy decisions of his presidency: Should he disappoint climate activists by approving the Keystone XL pipeline? And should he anger industry groups by imposing tough greenhouse gas limits on existing power plants?

But the president may have a third option: trying to placate both sides.

Greenlighting Keystone while he moves forward with the power plant regulations could limit the political fallout from either move, handing Republicans a win on the pipeline and Democrats a victory on climate change.

The White House isn’t tipping its hand, but environmental advocates who have closely followed the administration’s handling of both issues say Obama could roll out the two moves at or around the same time. And some climate-minded Democrats, such as Sen. Barbara Boxer, chairwoman of the Committee on Environment and Public Works, have signaled that they may not raise hell over Obama approving Keystone if it’s accompanied by aggressive action on other environmental fronts.

“It depends on what else he does,” the California Democrat said last month when asked whether OKing the pipeline would diminish Obama’s climate legacy. “If he did that but did 17 things that, you know, clean it up … I’d have a different opinion.”

One of the world’s leading scientific journals, Nature, has also advocated a package deal, writing in a late-January editorial that going ahead with both the pipeline and tough greenhouse gas rules would “give Obama an early opportunity to build some goodwill across the political spectrum.”

One problem: People with hard positions on each issue are already making it clear Obama can’t have it both ways.

Some top officials at environmental groups say they are on the lookout for any attempt by the president to use his climate agenda to distract them from the Keystone issue.

“Given that the Arctic melted last summer, we’re not really in a place where we get to try and ‘please both sides’ anymore,” said climate activist and 350.org founder Bill McKibben, who helped organize massive White House sit-ins against Keystone in 2011 and is planning protests with the Sierra Club on Feb. 17.

If Obama approves the pipeline, McKibben said, “it would not please the tens of thousands who have come out into the streets about Keystone in the last 18 months — the first environmental issue to draw that kind of mass attention in many years.”

“Talking about power plant rules would not quench the fire of opposition from approving KXL,” one top environmentalist said.

Similarly, some lawmakers on both sides of the aisle signaled this week that they have no intention of giving Obama a pass.

“If you do something that adds to the climate problem and then you do something to reduce the climate problem, does that cancel out?” asked Rep. Henry Waxman, the top Democrat on the House Energy and Commerce Committee. “It just seems to me that we’ve got to do everything that we can to reduce the carbon emissions that are causing the climate issue.”

Waxman, who has formed a Bicameral Task Force on Climate Change with Sen. Sheldon Whitehouse (D-R.I.), worried that approval of the pipeline would spur increased Canadian oil sands production, releasing stored-up carbon dioxide that would wreak havoc on the climate.

Meanwhile, Republicans warned Obama not to expect them to go easy on him over EPA regulations, even if he were to approve Keystone.

“I don’t think you can ever appease both sides of this debate,” said Rep. John Shimkus (R-Ill.), chairman of the Energy and Commerce Environment and the Economy Subcommittee. “If he approves Keystone, he’ll tick off the environmental left. If he does aggressive greenhouse gas regulations, he’s going to tick off the right. He’s going to tick people off either way.”

Rep. Ed Whitfield (R-Ky.), chairman of the panel’s Energy and Power Subcommittee, told the EPA to prepare for a fight over its expected climate regulations for existing plants.

“We’re going to have groups organized to oppose it and we’re going to be very aggressive in letting them know that if they try to start doing this with existing plants, they’re going to have a real battle on their hands,” he said after speaking at a conference Tuesday.

Of course, a Keystone approval is far from a done deal. With climate change crusader John Kerry now running the State Department, greens have new hope Obama will kill it.

The White House, which declined to comment for this story, has stressed that the Keystone decision will be made on the merits. Both actions are probably several months away, so it’s unlikely the White House has cemented its rollout plans.

Even so, there’s precedent for the administration trying to finesse its decision on Keystone, a project that has drawn fierce opposition from green groups but support from some Democratic-leaning labor unions. Obama got a reprieve from his no-win choice in late 2011 when the State Department opted to postpone its recommendation on the pipeline until after the 2012 election.

The State Department later promised a recommendation to Obama on Keystone within the first quarter of this year, but that seems likely to slip past March 31.

Meanwhile, the EPA is expected to move forward with climate change regulations for existing power plants after finalizing its greenhouse gas rules for new power plants, which were floated last March.

Some experts say tying the Keystone and greenhouse gas decisions could advance a broader energy agenda that tackles the climate crisis while taking advantage of the North American oil and gas boom. Obama has repeatedly expressed support for both sides of that equation.

“The administration must establish an overarching narrative that situates both their policies on the oil and gas boom and on climate protection in a broader economic and policy context, so packaging the decisions on Keystone and the GHG rules together could be a politically powerful way to help accomplish this,” said Paul Bledsoe, an independent energy consultant and former Clinton White House aide.

“Otherwise,” he said, “the administration risks a repeat of the first-term problem where interest groups on right and left defined the Obama agenda through targeted attacks on individual issues like the gulf drilling moratorium, shale gas fracking, EPA rule-making, and Keystone itself.”

Some Republican lawmakers speculate that the administration is already laying the groundwork to stifle environmentalists’ outcry if he approves the pipeline.

“He’s just setting you up for the approval of Keystone,” House Energy and Commerce Committee Chairman Fred Upton (R-Mich.) said he told Rep. Ed Markey (D-Mass.) after the president called for action on climate change during his inaugural address.

But one top oil industry official said it’s unlikely that the president will seek to please both sides. He thinks it’s increasingly likely Obama will reject Keystone outright, amid growing opposition from his liberal base.

“My sense is that the president will not try to nuance this by approving KXL concurrent with regulating GHG emissions from existing facilities,” the official said. “Rather, I think he will disapprove KXL and greenlight the EPA to continue its work.”