Next month, signatories to the 1989 Montreal Protocol on Substances that Deplete the Ozone Layer will convene in Kigali, Rwanda, to consider an amendment to the treaty that would gradually reduce, and eventually eliminate, the use of hydrofluorocarbons. HFCs, which are one of the six main greenhouse gases, are commonly used in air conditioners and refrigeration systems worldwide.
The amendment would be a boon for sustainable development, and could prevent the release of as much as 100-200 billion tons of climate-changing emissions by 2050. That would be enough to take the world a quarter of the way toward achieving the 2 degrees Celsius global-warming target set by the December 2015 Paris climate agreement.
The Montreal Protocol was established to repair the ozone layer, which protects all life on the planet from deadly levels of ultraviolet rays. So far, it has been a remarkable success, with nearly 100 ozone-destroying chemicals phased out over the past three decades. The ozone layer is healing and, according to the latest estimates, it could recover by 2065, saving trillions of dollars in global health care and agriculture costs.