As treaties go, the Montreal Protocol is often considered one of the most successful.
But the United States’ continued participation in the 1987 agreement to save the ozone layer is suddenly in question.
President Donald Trump’s proposed rescission package calls for eliminating funding to the Montreal Protocol, as part of a plan to claw back $437 million appropriated for international organizations and programs during the Biden administration.
The potential funding cuts coincide with a previously scheduled meeting next week in which treaty members will discuss technical aspects of the agreement. The U.S. has not confirmed whether it will attend, potentially escalating the Trump administration’s policy of snubbing global environmental conferences.
The White House directed questions to the Office of Management and Budget, which did not respond to a request for comment.
Proponents say there is little question that the Montreal Protocol benefits America by creating new markets for U.S. goods and protecting people from the sun’s harmful radiation.
The treaty has cut pollutants that burn holes in the ozone layer and contribute to planetary warming. It is supported by every country — and American businesses, environmentalists and both political parties.
But budget cuts that would deprive the treaty of funding — along with agencies like NOAA and NASA that help monitor whether countries are adhering to its provisions — could affect how well the treaty operates, experts argue.
“You need a monitoring network like we have, and improvements to it, to have the confidence that everybody’s playing by the rules,” said David Doniger, a lawyer with the Natural Resources Defense Council. “If the U.S. budget cuts were to threaten this network, it would be to our detriment.”
Here are five things to know about the Montreal Protocol and how Trump’s proposals could harm it.
What is it?
The 38-year-old agreement is the first United Nations treaty to achieve universal ratification, joined by 197 countries. Then-President Ronald Reagan called it “a model of cooperation” after signing it in 1988.
It helps to protect the ozone layer through binding commitments to eliminate the production and use of ozone-depleting chemicals once commonly found in refrigerators, air conditioners and aerosol sprays.
Unlike other climate pacts, such as the 2015 Paris Agreement, the Montreal Protocol requires countries to reduce pollution and restrict trade with nations that fail to meet the treaty’s goals.
“It says these gases are bad, you shall not make them,” said Durwood Zaelke, president of the Institute for Governance and Sustainable Development, a nonprofit that focuses on cutting short-lived climate pollutants.
The protocol has a financial mechanism called the Multilateral Fund that helps poorer countries meet their commitments to phase out harmful chemicals. It’s funded through contributions from the U.S. and other developed countries.
What has the Montreal Protocol achieved?
It has helped curb dozens of chemicals that degrade the ozone layer, including chlorofluorocarbons (CFCs). Many of the chemicals trap heat, so the treaty has also been a successful climate pact.
The 2016 Kigali Amendment to the Montreal Protocol goes further by targeting a class of coolants known as hydrofluorocarbons, or HFCs. They were meant to replace CFCs because they don’t have an ozone effect, but HFCs were found to be far worse for the climate than carbon dioxide.
Scientists say the Montreal Protocol will prevent as much as 2.5 degrees of additional warming by the end of this century, with Kigali adding benefits.
It has also helped protect forests and other ecosystems that suck up planet-warming carbon dioxide, making the ozone treaty a vital tool in combating climate change.
“It’s been the most effective international mechanism by which we’ve avoided egregious human health impacts in the form of skin cancer [and] cataracts” but also the consequences of warming such as intensifying wildfires, hurricanes and droughts, said Richie Kaur, an advocate for superpollutant reduction at NRDC.
Why has it earned bipartisan backing?
Short answer: It’s good for business.
In 2020, during Trump’s first term, Congress passed the American Innovation and Manufacturing Act, or AIM, which mandates the phasedown of HFCs and brings the U.S. in line with the climate goals of the Kigali Amendment. Two years later, President Joe Biden ratified Kigali with approval from the Senate, making the U.S. the 138th country to sign on.
The U.S. Chamber of Commerce was a leader in advancing those policies.
“Our message was that business is working on the transition, it’s going to benefit the economy, it’s going to open up access to markets, level the playing field for U.S. participation in those markets, and the economic story has continued to be a good one,” said Chuck Chaitovitz, vice president of environmental affairs and sustainability at the Chamber.
Ratification of Kigali was driven by a rare collaboration between industry and environmental organizations. It was also pushed forward by a bipartisan group of senators who argued that ratifying it would “help secure America’s place as a global leader” in manufacturing by offering U.S. products an advantage in global markets.
Is the treaty under threat?
It’s unlikely that the U.S. would withdraw from the Montreal Protocol, in part because it could hurt American businesses. The White House fiscal 2026 budget request for EPA would continue support for provisions of the Clean Air Act and the AIM Act that address domestic obligations to the Montreal Protocol.
But cuts to international funding could hobble it.
“The U.S. needs to continue its domestic implementation programs as well as their support for the international process,” said Kevin Fay, executive director of the Alliance for Responsible Atmospheric Policy, an industry coalition. “And a key part of that international support is helping to promote U.S. technology and U.S. industry and jobs around the globe.”
U.S. contributions to the treaty’s multilateral fund help other countries meet their obligations under the Montreal Protocol. And when a country like India looks for air conditioners that are made without harmful chemicals, they often buy American-made products.
“The multilateral fund is critical to creating markets in developing countries for U.S. products,” said Josh Klein, a former senior Democratic staffer for international environmental policy on the Senate Foreign Relations Committee.
While the U.S. isn’t the only country that contributes money to the fund, it has provided roughly a quarter of all funding since its establishment in 1991. The U.S. also offers experts to the protocol’s scientific advisory panel. Staffing cuts at NOAA and NASA could affect that work.
What’s next?
Officials from around the world will gather next week in Bangkok for a regular meeting to discuss issues that underpin the treaty, including funding and atmospheric monitoring. The State Department wouldn’t confirm whether the U.S. was sending a delegation.
A State-led review of whether the U.S. should withdraw from certain international organizations and treaties is expected in early August. The Montreal Protocol is likely to survive because of its popularity among business groups, but the president’s planned budget cuts could degrade its ability to function, advocates said.
“We do know that it’s up to Congress whether to approve these things, whether it’s in the form of rescissions this year or the budget request for next year,” said Doniger, of NRDC.
In the past when deep cuts have loomed over NOAA and NASA, they have been rejected by Congress.
“We’re hoping that happens again,” Doniger added.
