The Earth’s protective layer is on track to recover within four decades as damaging airborne chemicals are phased out, helping to shield humans from the sun’s rays and limit global warming, a UN-backed scientific panel said.

Scientists first identified a hole in the ozone layer, which helps filter out ultraviolet rays from the sun, in 1985.

A rare international agreement was reached in 1987 to phase out gases including chlorofluorocarbons (CFCs), which were used in products such as air conditioners, refrigerators and deodorants but were breaking down ozone in the upper atmosphere. A 2016 update to the so-called Montreal Protocol also phased out hydrofluorocarbons (HFCs), which do not directly deplete ozone but have a strong …