For the first time ever, researchers have detected a significant dip in atmospheric levels of hydrochlorofluorocarbons — harmful gases that deplete the ozone layer and warm the planet.

TLDR:

Almost 30 years after nations first agreed to phase out HCFCs, which were widely used for air conditioning and refrigeration, scientists say global concentrations peaked in 2021. Since then, the ozone-depleting potential of HCFCs in the atmosphere has fallen by about three-quarters of a percentage point, according to findings published in the journal Nature Climate Change.

Though small, that decline comes sooner than expected, scientists say — and it represents a significant milestone for the international effort to preserve the layer of Earth’s stratosphere that blocks dangerous ultraviolet sunlight.