Nearly 200 countries took a key step in the fight against global warming when they agreed to phase out the use of a powerful chemical used in air conditioners and refrigerators.

Here’s what happened and why it matters.

What is this agreement all about?

Under the amendment forged in Kigali, Rwanda, representatives from 197 countries agreed in October to phase out hydrofluorocarbons, or HFCs. These are potent greenhouse gases that can contribute to climate change. The reductions will be made in three stages, with wealthier nations reducing use of HFCs more quickly than poorer countries. The agreement will bring in a new era of air conditioning.

(State Dept.)


Does this have anything to do with the Paris climate agreement?

The historic Paris climate agreement was designed to cut greenhouse gas emissions and limit a rise in global temperatures. The Kigali amendment to phase out HFCs is seen as a step in that direction. The Paris agreement, which just passed the ratification threshold to enter into force, consists of voluntary pledges that differ by country. The Kigali agreement on HFCs is an amendment to the 1987 Montreal Protocol — a treaty — so it will be mandatory for countries that join.

Why is this happening now?

The Montreal Protocol was designed to close the hole in the ozone layer by banning coolants called chlorofluorocarbons, or CFCs, which are greenhouse gases and damage the ozone layer. These chemicals were used as refrigerants and also used in aerosol sprays and solvents. After the Montreal Protocol was signed in 1987, HFCs were developed as a substitute for CFCs. More research since then has concluded that HFCs are greenhouse gases that can be thousands of times more potent than carbon dioxide in contributing to climate change, but do not damage the ozone layer. That’s why the amendment was needed and approved.

So did your country act? If you see it below, the answer is yes.

(State Dept.)
(State Dept.)