Top Republican lawmakers are planning a wide-ranging offensive — including outreach to foreign officials by Senate Majority Leader Mitch McConnell's office — to undermine President Barack Obama's hopes of reaching an international climate change agreement that would cement his environmental legacy.

The GOP strategy, emerging after months of quiet discussions, includes sowing doubts about Obama's climate policies at home and abroad, trying to block key environmental regulations in Congress, and challenging the legitimacy of the president's attempts to craft a global agreement without submitting a treaty to the Senate.


A top policy aide to McConnell (R-Ky.) has had conversations with a select group of representatives from foreign embassies to make it clear that Republicans intend to fight Obama's climate agenda at every turn, sources familiar with the efforts say.

Sources say the aide, Neil Chatterjee, hasn't tried to persuade other countries to oppose a climate deal, though he is informing them about the GOP's options for undercutting it. He has had conversations with officials representing both developed and developing countries. Environment & Energy Publishing first reported on his efforts.

McConnell himself warned foreign leaders last spring to "proceed with caution before entering into a binding, unattainable deal” with Obama, noting that "two-thirds of the U.S. federal government" — Congress and the Supreme Court — hasn't signed off on the president's plans.

Republicans have no direct way of interfering with December's climate summit in Paris, and Obama's domestic climate strategy relies almost entirely on executive branch regulations that don't require Congress' approval. But the resistance could threaten to gum up progress in carrying out Obama's policies, making it easier to undo them if the GOP retakes the White House in 2016.

The Republican tactics are partly aimed at an audience abroad: countries that have long expressed doubts about the sincerity of the United States' climate efforts.

In Paris, representatives of nearly 200 nations will try to hammer out an agreement for curbing the greenhouse gas emissions blamed for warming the planet and boosting sea levels. By design, the State Department is pushing for a broad political agreement that has buy-in from each country but won't carry the legal authority of a treaty — getting around the Constitution's requirement that treaties be ratified through a two-thirds vote in the Senate.

Incensed by that workaround, GOP aides are consulting with legal scholars about whether they can insist that any climate deal come before the Senate, sources said. At the very least, that argument can highlight the fact that a non-ratified agreement won't bind Obama's successors.

"Without Senate ratification, what value does Paris really have?” asked one GOP aide, who declined to speak on the record because Republicans have not finished their strategy.

"If it’s not called a treaty, are there parts of it that are so complex that you could argue they are a treaty?" the aide added. "While the president is saying it’s a political commitment, there are still some serious implications for domestic policy.”

The political reality is that any pact coming from the Paris conference would be dead on arrival in the Senate — the very reason the administration doesn't plan to submit it there. There is "no chance" that such an agreement could clear the two-thirds hurdle, one Republican energy lobbyist said. "There are few certainties in life, but that is one of them."

Administration officials say they are confident that Republicans won't succeed in undermining the international agreement. So far, foreign diplomats do not appear to have been rattled by GOP opposition. Negotiations are moving forward, and many countries remain confident that they'll be able to strike a deal in Paris, even if the agreement isn't strong enough on its own to avoid the worst effects of climate change.

Massachusetts Democratic Sen. Ed Markey said Obama's critics can't be allowed to torpedo the talks.

"Climate deniers and opponents who send a 'can't do' message only undermine America's leadership on the international stage," Markey said in a statement Friday. "We’re entering the final stretch to crafting an agreement in Paris that includes all countries in the world doing their fair share to address global warming. Current signs point to successfully reaching the finish line, and we cannot let efforts to block action domestically derail an international victory."

GOP aides say Republicans are pursuing at least two lines of attack against Obama's plans.

First, they're trying to undo the Environmental Protection Agency's just-unveiled climate regulations for power plants, which underpin the United States' pledge to cut its greenhouse gas emissions 26 percent to 28 percent below 2005 levels by 2025. The U.S. will miss that target if the courts or Congress overturn the EPA rules, Republicans contend.

Republicans plan to challenge the rules using the Congressional Review Act, a seldom-invoked law that allows lawmakers to repeal a regulation with a simple-majority vote — although Obama would certainly veto that move. McConnell has also encouraged governors in all 50 states to refuse to comply with the EPA regulations, though he's had only mixed success even among Republican governors. And opponents plan to unleash lawsuits that could tie the regulations up in court for years.

Second, Republicans plan to block Obama's pledge to provide billions of dollars to help poor countries adapt to the effects of a warming planet. Obama has promised that the U.S. will contribute $3 billion to an initiative called the Green Climate Fund, including $500 million in the next fiscal year. Poor countries have warned that their support for a deal in Paris will hinge on industrialized nations making ambitious commitments to the fund, as well as other financial pledges from wealthy nations like the United States.

Meanwhile, the Senate Environment and Public Works Committee plans to hold a hearing soon on the issue of whether Obama should have to submit the climate agreement for ratification.

Republicans are considering making the case that Congress should get to review such a high-profile agreement, whether it's technically a treaty or not, a strategy that echoes the one lawmakers are using to review the deal on the Iranian nuclear program. But unlike with the Iran deal, Republicans aren't likely to get much support from Democrats for reviewing the climate agreement.

Either way, GOP lawmakers say they'll make the case that the climate deal is largely meaningless because a future Republican president will be under no obligation to comply with it.

"The president is only pursuing a political commitment and there’s nothing legally binding about it," another GOP aide said.

Republicans are also considering legislation that would respond to the Paris talks, including a possible resolution expressing their opposition to the deal. That could be similar to the symbolic 95-0 vote the Senate took in 1997 to repudiate the Kyoto climate agreement that the Clinton administration was negotiating at the time.

Experts said lawmakers would have a tough time forcing Obama to submit the Paris agreement to Congress.

If diplomats negotiate a political deal, "I think the generally accepted view is that the president would get to decide whether to accept the agreement, based on his constitutional foreign affairs powers," said Daniel Bodansky, an Arizona State University law professor who served as a State Department climate coordinator at the end of the Clinton administration.

"I don’t see anything [Republicans in Congress] can do other than express their view," said Jeremy Rabkin, a George Mason University professor who teaches international law.

But Rabkin, a critic of the administration's climate policies, added that Obama can't bind future presidents to the agreement if it isn't a treaty. "You live by the rhetoric, you die by the rhetoric," he said.

