Negotiators from nearly 200 nations reached a historic deal to phase down emissions of hydrofluorocarbons (HFCs) — potent greenhouse gases used in air conditioners and refrigerators. The agreement, a major expansion of the 1987 Montreal Protocol, which eliminated the use of the ozone-depleting chlorofluorocarbons, was finalized during a United Nations meeting in Kigali, Rwanda.
The Antarctic ozone hole reached its annual peak size on Sept. 11, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA). The size of this year’s hole was 24.1 million square kilometers, an area roughly the size of North America.
United Nations officials hailed on Tuesday the progress made in reducing damage to the ozone layer and the vital role played by one of the most successful environmental treaties in history in phasing out ozone-depleting substances.
The ozone layer has seen unprecedented damage in the Arctic this winter due to cold weather in the upper atmosphere. By the end of March, 40% of the ozone in the stratosphere had been destroyed, against a previous record of 30%.