Nearly 200 countries agreed Saturday to the early phase-out of a potent greenhouse gas that is projected to warm the planet 0.5 degrees Celsius by the end of the century.
At a U.N. conference in the Rwandan capital of Kigali, negotiators reached a deal to amend the nearly 30-year-old Montreal Protocol to phase out hydrofluorocarbons, or HFCs, which are synthetic chemicals used in refrigerators and air conditioners. HFCs weren’t included in the sweeping Paris climate agreement signed earlier this year.
Unlike the Paris deal, which included broad, voluntary pledges to cut emissions, the Rwanda deal covers a single pollutant and is legally binding. “It is likely the single most important step we could take at this moment to limit the warming of our planet and limit the warming for generations to come,” U.S. Secretary of State John Kerry said.
During the negotiations, the U.S. and EU pushed for an earlier date for the phase-out of HFCs, while countries like India, Brazil, and China wanted a later date due to the increasing demand for air conditioning in those developing nations. “No one, frankly, will forgive you if you cannot find a compromise at this conference,” executive director of the United Nations Environmental Program (UNEP) Erik Solheim told the U.N. members as the meeting opened, according to Reuters.
In the end, the countries agreed to a three-tier deal: The United States and European Union nations will freeze production and consumption of HFCs by 2018, while China, Brazil, and all of Africa will freeze their HFC use by 2024. A group of the world’s hottest countries (including India, Pakistan, Iran, Saudi Arabia, and Kuwait) will have the most lenient schedule, freezing HFC use by 2028.
Developed countries also agreed to pay an unspecified amount to finance the transition and find alternatives to HFCs. The amount of funding, expected to be in the billions globally, will be hammered out at the next meeting of the parties to the deal in Montreal in 2017, the UNEP said.
Though they account for a tiny amount of global warming right now, the use of HFCs has skyrocketed in recent years, and they’re on track to account for up to 19 percent of global emissions by 2050, according to one study. HFCs also have a global warming potential thousands of times higher than carbon dioxide. That’s why it’s important to phase them out now, and not later.
Signed in 1987 and brought into force in 1989, the Montreal Protocol joined 197 U.N. members against the use of ozone-depleting chemicals. The fear was that ozone-depleting emissions were eating away at the stratospheric ozone layer, which filters ultraviolet radiation that causes skin cancer. There was a giant hole in the ozone layer over Antarctica, and the agreement brought U.N. members into lockstep to hammer out a solution.
The 1987 deal was a massive success, with Kofi Annan calling it at the time “perhaps the single most successful international agreement to date.” As a result of the agreement, ozone-eating chlorofluorocarbons, or CFCs, which were used in refrigeration and air conditioners, among other things, were almost entirely phased out by 2010. The ozone layer is expected to recover in the coming decades.
But in the wake of the decline of CFCs, the use of HFCs skyrocketed as a replacement. By ending one problem — chemicals chewing a hole in the ozone — the protocol gave way to another: the increase of a potent greenhouse gas that is contributing to climate change. One study projected that phasing out HFCs could avoid 0.5 degrees Celsius of warming by 2100 — a significant number considering the Paris climate deal aimed to cap global warming at no more than two degrees Celsius.