A legal debate is swirling about President Donald Trump’s intention to withdraw the U.S. from the world’s oldest climate treaty.
At its center are questions about whether it’s legal for a president to unilaterally leave a treaty approved by the Senate — and if a future president could reenter it without the Senate voting again.
The United Nations Framework Convention on Climate Change serves as the foundation for international efforts to address global warming and is the precursor to the 2015 Paris Agreement. Participation in Paris depends on being a signatory to the convention.
President George H.W. Bush ratified the treaty with the Senate’s overwhelming approval in 1992. Trump threw that into reverse two weeks ago when he identified the UNFCCC among dozens of international organizations from which he would cease engagement. It came after he has shuttered climate offices across the government, halted offshore wind projects and urged world leaders to abandon efforts to slow global warming.
Now Trump is testing the reach of his executive authority by exiting the UNFCCC.
According to the treaty’s withdrawal clause, the U.S. can leave the convention a year after notifying the United Nations in writing. (It’s the same timeline for exiting the Paris Agreement, which will take effect for the U.S. next Tuesday.)
Whether a president can unilaterally leave a treaty under U.S. law is not addressed in the Constitution. The Supreme Court declined to answer the question in 1979, in Goldwater v. Carter, when President Jimmy Carter terminated a bilateral defense treaty with Taiwan, in order to establish formal relations with China. Congress opposed the move and Sen. Barry Goldwater (R-Ariz.) sued with other lawmakers. A four-justice plurality determined that while the Constitution outlines the Senate’s role in ratifying a treaty, it is silent on the chamber’s role in abandoning one.
Presidents have unilaterally withdrawn from treaties for decades. Those include the Anti-Ballistic Missile Treaty, which President George W. Bush withdrew from in 2002; and a treaty that normalized relations with Iran that Trump quit during his first administration.
“In the last 50 years, almost all U.S. treaty withdrawals have been done unilaterally by presidents,” Curtis Bradley, an international law professor at the University of Chicago, said in an email.
The mainstream legal view is that the president may quit a treaty if it’s permitted under international law and “neither the Senate’s resolution of advice and consent nor a congressional law has put limits on withdrawal,” former deputy climate envoy Sue Biniaz and law professor Jean Galbraith, argue in a recent piece in Just Security.
Some legal scholars argue that just because presidents exercise the practice of quitting treaties, it doesn’t mean the law grants them the power to do it. There have been various attempts in recent years to codify whether the power of withdrawal is exclusive to the president, or if they need help from lawmakers.
So what happens now? And is it likely that Trump’s single-handed withdrawal from the UNFCCC will be legally challenged?
First, a few questions need answers, said Harold Koh, an international law professor at Yale Law School and a former State Department legal adviser.
One is timing.
An opponent of Trump’s move could trigger a lawsuit at any time, but showing standing to sue — which legal scholars say is likely to prove challenging — would be harder if the withdrawal hasn’t been formally instituted.
A White House official said the State Department was preparing the official notification that will be sent to the U.N. Once that occurs, the U.S. would withdraw from the treaty one year later.
Next, who can bring a case?
Lawmakers could argue that the president’s action seeks to nullify a legislative branch vote and legally challenge it using what’s known as congressional standing, said Koh.
Or Congress could pass a bill saying congressional approval is needed before Trump can withdraw. The chances of that are extremely unlikely in a Republican-dominated Congress, where lawmakers have generally shrugged off Trump’s plan to quit the treaty. Even if both chambers passed such a bill, Trump could veto it. Overriding it would require a two-thirds vote in the House and Senate.
It’s also possible that another party could sue Trump, such as an individual, a state or an environmental group. The case might be difficult to bring to court, because they would have to show standing — or that they were injured by the withdrawal, said Koh.
“The standing problem with climate change, obviously, is that everybody is harmed by climate change,” he added. “So it’s hard for one individual to claim an unusual or extraordinary harm.”
A state, such as California or Massachusetts, could argue that global warming leads to a greater chance that disasters, like floods, cause increasingly expensive damage to its infrastructure or economy.
The challenge there is that the UNFCCC doesn’t contain specific obligations to reduce emissions, making it hard to show how a particular state could be harmed in a concrete way by the U.S. leaving the convention.
“I think there are real and serious harms to U.S. withdrawal,” said Galbraith at the University of Pennsylvania Law School, who added that tying those damages to a geographic location, and showing how they could be redressed, would be difficult.
“If there is a party who can sue, my guess is that the courts would either hold that the dispute presents a political question that cannot be resolved by the judiciary or they would side with President Trump on the merits,” said Bradley, from the University of Chicago.
Legal challenges could also await a future president who tries to exert executive power to reenter the treaty.
The main question would be whether Trump’s withdrawal canceled the Senate’s prior consent, requiring new legislative action, said Michael Gerrard, director of the Sabin Center for Climate Change Law at Columbia University. That’s never been decided.
“It’s possible the courts would say that’s a political question the courts can’t handle. It’s also possible courts say it’s not a political question, but it doesn’t have standing,” Gerrard said.
Galbraith of UPenn thinks a future administration would be able to reenter the UNFCCC based on the Senate’s 1992 ratification.
To do that, a president might issue a proclamation or memo outlining their decision. Under international law, they would only need to notify the U.N. in writing of their decision to rejoin, Galbraith said. It would take 90 days to become official.
Of course, that could be challenged. And the case could end up at the Supreme Court, which traditionally gives deference to presidents on matters of foreign affairs.
Lesley Clark contributed to this report.
