International negotiators are gathering in Kigali, Rwanda, with the goal of phasing down one of the most potent and rapidly expanding greenhouse gases affecting the climate.

Momentum is building for taking action on hydrofluorocarbons (HFCs), a family of industrial chemicals used worldwide in air conditioners, refrigeration, foam products, and aerosols.

• On the sidelines of the recent U.N. General Assembly, more than 100 nations signed a declaration calling for an amendment to the Montreal Protocol to ambitiously deal with HFCs, with an early freeze date for developing countries and an early first reduction step for developed countries.
• To jump start the transition away from HFCs, 16 donor nations have offered $27 million in new and additional money for use by developing countries in limiting HFC use in 2017. Donor countries are also committing to support the longer-term phase-down costs under the Montreal Protocol’s Multilateral Fund.
• In an unprecedented move, a group of philanthropists (19 foundations and private individuals including Bill Gates and Tom Steyer) have offered an additional $53 million to developing countries to support efforts to move from HFCs to more energy-efficient alternatives.
• More than 500 companies and organizations issued a call to action in support of an ambitious agreement on an HFC phasedown at the 28th Meeting of the Parties to the Montreal Protocol October 10-14.

Action on HFCs is the single most significant step nations can take this year to advance the goal established in the Paris Agreement of limiting global temperature increases to well below 2 degrees Celsius. Estimates are that an ambitious HFC amendment would reduce global warming by as much as 0.5 degrees by the end of the century.

While momentum for an ambitious agreement this year is strong and building, it is by no means assured. Even with more than 100 nations on board, reaching an international consensus in Kigali will not be easy.

A large number of developed and developing countries have supported a developing country freeze in HFC use beginning around 2021, but India has supported a 2030 freeze date and Gulf Cooperation Council countries proposed a 2028 freeze.

Issues under discussion include the costs and availability of alternatives, the role and timing of patent protections, the rules governing support of projects under the Multilateral Fund, and the need for updated standards for the safe handling and use of more flammable refrigerant alternatives. While there is general support for incorporating enhanced energy efficiency into the transition away from HFCs, there are questions about the ways to achieve this objective.

Solutions are on the table for all of these issues. Given progress to date and the financial resources now available to developing countries to support an ambitious HFC amendment, agreement in Kigali is well within reach. The costs of acting to reduce HFCs are small compared to the very real and present costs of inaction to limit changes to our climate.