Leaders and negotiators from nearly 200 countries surmounted divisions between rich and poor countries and maintained diplomatic momentum against global warming with a binding agreement this weekend to phase out the use of some of the most potent greenhouse gases.
The culmination of prolonged negotiations, the agreement tackles the use of hydrofluorocarbons (HFCs), widely used in air conditioning, and it could have an unusually swift impact on rising temperatures within this century. The breakthrough came on the last night of talks in Kigali, Rwanda, sponsored by the United Nations to update the 1987 Montreal Protocol.
This was the third notable achievement reached around the UN's environmental negotiating table in recent weeks. It follows the ratification of the Paris Agreement on climate change by enough nations to let that pact enter into force in November, and an October accord addressing emissions by the world's airlines.
The Kigali accord calls on all countries to dramatically curb their production and use of HFCs by 2050 and transition to climate-friendly alternatives.
Compared to carbon dioxide, HFCs can be hundreds to thousands of times more effective at trapping heat in the atmosphere. They are also the fastest-growing source of climate emissions, with the potential to cause up to half a degree Celsius of warming by 2100.
Under the Paris deal, the world agreed to limit warming to between 1.5 to 2 degrees Celsius compared to pre-industrial levels to prevent catastrophic warming. This is only possible if the world achieves no net addition of greenhouse gases by the second half of this century. Countries have submitted plans to gradually reduce their emissions, but those plans don't go far enough. The new deals on aviation, and especially on HFCs, will help bring the targets closer and have won praise from world leaders, negotiators, industry members and environmentalists.
President Barack Obama called the Kigali amendment "an ambitious and far-reaching solution" to the climate crisis and "a significant contribution towards achieving the goals we set in Paris."
"This is the biggest step we have taken this year towards making the goals of the Paris Agreement a reality, and ensuring we do what is necessary to save my country," said Mattlan Zackhras, an official from the Marshall Islands, which is endangered by rising sea levels. "We all know we must go further, and we will go further," he added.
Here's a guide to HFCs and their climate impacts, the specifics of the deal and how it fits into the broader efforts to address climate change.
What are HFCs?
Hydrofluorocarbons are gases primarily used for cooling in air conditioners and refrigerators. They were developed by the chemical industry to replace chlorofluorocarbons (CFCs), which were found to deplete the ozone layer that shields the Earth from harmful ultraviolet radiation from the sun. Under the Montreal Protocol, an international agreement developed in 1987 and entered into force in 1989, countries agreed to phase out CFCs and replace them with gases that were less damaging to ozone. While the Montreal deal is working—the ozone hole is showing signs of healing—there was a big side-effect: the contribution to global warming from HFCs.
Why is it important to control them?
As air conditioners and fridges wear out over time, or are improperly disposed of, HFCs can leak into the atmosphere. Once there, they trap heat much more effectively than carbon dioxide, even though they don't last as long. Experts say that bringing them under control is one of the most cost effective ways to control global warming in the next few decades.
While some HFCs only remain in the atmosphere for a few years to decades, others can last a few centuries. Emissions from HFCs are currently on the rise, growing about 10 percent a year as developing countries, in particular, gain access to air conditioning and refrigeration. If these emissions grow unchecked, scientists have warned that they could contribute to 0.5 degrees Celsius of warming by 2100.
What does this agreement do?
This deal, a new amendment to the legally binding Montreal Protocol, includes timelines for countries to slow and then decrease their consumption of HFCs. It also calls for research into and the development of alternative gases, with a flexible framework for the industry to make the transition. Finally, the Kigali amendment provides financial assistance to poor nations to get off HFCs.
Developed countries will lead the phaseout and must begin slashing HFCs by 2019. The United States and the European Union have already started. There's a slightly different compliance schedule for Russia, Belarus and three neighboring countries. More than 100 developing countries including China and South Africa have until 2024 to freeze their HFCs consumption levels; after that point, they must gradually decrease them. A final group of countries, including India, Iran, Pakistan and the Gulf States, have more time—until 2028—to freeze their HFCs. All countries must reduce their consumption by at least 80 percent before 2050.
This deal "is equal to stopping the entire world's fossil-fuel CO2 emissions for more than two years," said NRDC's David Doniger.
What were the main sticking points?
There were two main sources of friction during the talks: the pace of the emissions reductions and who will pay for it.
Some countries urgently concerned about the looming risks of climate change, such as the Marshall Islands, entered the negotiations pushing for an earlier phase out of HFCs; meanwhile, India and others wanted more time. For both of these groups, the final deal was a compromise. But a key feature of the Kigali amendment is that participating members will regularly review its progress, leaving the door open for a faster reduction in HFCs than the deal currently dictates.
How much will it cost?
The global phase-out of HFCs is estimated to cost billions of dollars. While countries like the United States are already transitioning away from HFCs, this switch will likely be a major financial burden for countries such as China and India, with the fastest growing markets. That's why the U.S. and European Union are largely paying for research on climate-friendly gases. Many countries also expect the private sector will play a major role in facilitating the switch from HFCs and driving down the high costs.
What does this say about the state of the global climate struggle?
The HFCs agreement, taken together with the Paris deal and aviation industry's commitment, shows world leaders' sense of urgency in responding to the climate crisis. While none of these agreements go far enough to avert the worst impacts of climate change, they signal momentum.
The Kigali amendment "amplifies the important message we've been sending to industry and the private sector: Entrepreneurs and innovators everywhere can continue to invest in climate solutions with confidence," Kerry said in a statement. "Nations in every part of the world are committed to changing the course our planet has been on. We are moving toward a more sustainable world – and our pace is quickening."