UN says ozone layer slowly healing, hole to mend by 2066DENVER (AP) — Earth’s protective ozone layer is slowly but noticeably healing at a pace that would fully mend the hole over Antarctica in about 43 years, a new United Nations report says.The global average amount of ozone 18 miles (30 kilometers) high in the atmosphere won’t be back to 1980 pre-thinning levels until about 2040, the report said.Scientists and environmental advocates across the world have long hailed the efforts to heal the ozone hole — springing out of a 1987 agreement called the Montreal Protocol that banned a class of chemicals often used in refrigerants and aerosols — as one of the biggest ecological victories for humanity.Chlorine levels are down 11.5% since they peaked in 1993 and bromine, which is more efficient at eating ozone but is at lower levels in the air, dropped 14.5% since its 1999 peak, the report said.“There has been a sea change in the way our society deals with ozone depleting substances,” said scientific panel co-chair David W. Fahey, director of the U.S. National Oceanic and Atmospheric Administration’s chemical sciences lab."