After nearly 30 years of targeting substances that destroy the ozone layer, the Montreal Protocol will for the first time target greenhouse gases, Robynne Boyd reports for Scientific American. Member states of the United Nations have met in Kigali, Rwanda to discuss just that through an amendment to the protocol that would set the terms for the rapid phasedown of hydrofluorocarbons (HFCs). The most common of these coolants is refrigerant is HFC-134a, a powerful greenhouse gas “which has 1,430 times more warming potential than carbon dioxide (CO2) over 100 years,” Boyd reports.

“An ambitious amendment is the quickest and least expensive way to reduce the effects of climate change,” says Durwood Zaelke, president of the Institute for Governance and Sustainable Development. Durwood tells Scientific American that a phasedown could prevent the equivalent of 100 to 200 billion tons of CO2 being released into the atmosphere by 2050. That prevention could avert half a degree Celsius of warming by the end of the century, and, as UNFCCC Executive Secretary Patricia Espinosa says, bring us one-quarter of the way toward reaching the Paris Agreement.