By Keith Goldberg

November 10, 2016 - President-elect Donald J. Trump's victory Tuesday dealt a devastating blow to the controversial Clean Power Plan and other regulations aimed at curbing climate change, and could render what had been closely watched D.C. Circuit challenges to the CPP and other Obama administration rules moot, experts say.

Trump vowed during his campaign to rescind the CPP, the linchpin of President Barack Obama's climate change strategy which slashes carbon emissions from existing power plants by 32 percent from 2005 levels. The rule is currently on hold while its legality is challenged, and the D.C. Circuit is expected to issue a ruling soon.

But Trump's ascent to the White House could render the decision moot, and doom the CPP, as currently crafted, to the regulatory dustbin, experts say.

"I think we are looking at some path ... with the Clean Power Plan being essentially extinguished," George Washington University law professor Emily Hammond said.

Reed Smith LLP counsel Jennifer Smokelin says there are basically three litigation paths the CPP could take, but with Trump's election, none of them are promising for the rule. The D.C. Circuit could nix the rule and the Trump administration could leave it at that, Smokelin said. States and environmental groups that have intervened in support of the rule could appeal to the U.S. Supreme Court, but they'd be going it alone and face the possibility of a Trump-appointed ninth justice on the bench.

The appeals court could remand the CPP to the U.S. Environmental Protection Agency to shore up its reasoning for the rule, but a revised version could be substantially changed and weaker than the original one, Smokelin said.

The third, and most favorable, path for the CPP is if the D.C. Circuit were to uphold the rule, prompting an appeal to the Supreme Court, which could conceivably still be in a 4-4 deadlock, according to Smokelin.

"But the EPA will have to defend it at the Supreme Court level, and how vigorous that defense would be would depend on the resources the Trump administration would want to put into it," Smokelin said.

Trump might not even have to wait for the courts to act. There are several pending petitions for reconsideration of the CPP at the EPA, giving him an opening to either eliminate the rule or revise it to his preferences, according to Baker Botts LLP environmental partner Megan Berge.

"The Trump administration would have the table set for it to rescind the rule," said Berge, whose firm is representing CPP challengers.

However, rescinding or drastically revising the CPP would require an additional rulemaking process. Environmental groups and states that support the rule in its original form would almost assuredly challenge the resulting action in court, and experts say a Trump-led EPA would have to convince a court that its decision to reverse the agency's earlier position was reasonable, experts say.

"They can do it, but it will take time," University of Maryland law professor Robert Percival said.

For other climate regulations crafted by the Obama administration currently being challenged in court, such as the EPA rule clamping down on methane emissions from new and modified oil and gas infrastructure, their outlook is similarly grim, experts say.

"For all the major rules that EPA has issued and are tied up in litigation, that same analysis applies," Hammond said.

As for climate rules that are still in the proposed stage, they would likely die on the vine if Trump follows through on his commitment to roll back U.S. climate policy, experts say. For rules that have already been upheld by courts — such as portions of the EPA's so-called tailoring rule that allow existing power plants to be regulated for greenhouse gases as long as they are being regulated for other pollutants as well — the challenge they face under a Trump administration is decreased enforcement, something over which the EPA has wide discretion, experts say.

"If a rule has been finally promulgated and EPA is not enforcing it, environmental groups and states may bring citizen suits to force the agency to enforce them, but typically, those suits take several years to resolve," said Michael B. Gerrard, director of Columbia Law School's Sabin Center for Climate Change Law. "If the administration doesn't want to move forward with them, it doesn't have to, unless there's some other compulsion or court order forcing them to do that."

A Trump administration, in conjunction with a Republican-controlled Congress, also has the power of the purse to not only slash funding for the EPA and other agencies, but impose conditions barring them from spending the funds they do receive on implementation and enforcement of climate regulations, experts say.

"That's not just starving them of money, it's literally putting qualifications on the amount of money that can be spent," Smokelin said.

Trump has also vowed to rescind U.S. involvement in the historic Paris climate change agreement that went into effect last week. Given that the U.S. ratified the agreement via an executive order from Obama, experts say that undoing it could be an easier task than undoing the CPP, though formally withdrawing from the pact is a multiyear process under the terms of the agreement.

"Acting by executive order, it's live by the sword, die by the sword," Smokelin said. "That order you enact can be unenacted by a new executive."

The expected rollback of climate regulations under a Trump administration may heighten the Balkanization of state climate policies that already exists, experts say. States like California and New York are moving forward aggressively with their own climate change programs, with some states already exceeding carbon reduction goals laid out by the CPP. Meanwhile, states that have fought the Obama administration over its climate rules now have an incentive to stand pat.

That could be a compliance headache for companies working in multiple states, experts say.

"It's entirely possible that a company that works across a lot of state boundaries will have different regulatory regimes to manage and different air policies it'll have to comply with," said Scot Anderson, who heads Hogan Lovells' global energy and natural resources practice group.

But Berge said in many ways, that's business as usual for companies. For example, utilities in many states are required to purchase increasing levels of renewable power, regardless of the CPP's ultimate fate.

"For many companies, their states are driving the climate bus, not EPA," Berge said. "In those states, the EPA's actions will have no effect whatsoever. They'll miss the federal support, but companies in those states will be taking actions to meet their state requirements, no matter what."

Meanwhile, the potentially lengthy — and litigious — process of unwinding regulations means energy companies can't assume Tuesday's election will result in all of the Obama administration's climate rules being rescinded, experts say.

"For most energy companies, they're looking at this change and saying they're not sure what the outcome will be and what the timeline will be," Anderson said.