Ozone-depleting CFCs on the rise despite ban: study

Despite being banned under the Montreal Protocol, five chlorofluorocarbons (CFCs) have reached record levels in the atmosphere from 2010 to 2020, according to a study published in the journal Nature Geoscience. The increase was probably due to leakage during the production of chemicals that are meant to replace CFCs, including hydrofluorocarbons (HFOs). Although at current levels they do not threaten the recovery of the ozone layer, they contribute to a different threat, joining other emissions in heating the atmosphere.