The Associated Press reports:
Earth’s protective ozone layer is finally healing from damage caused by aerosol sprays and coolants, a new United Nations report said. The ozone layer had been thinning since the late 1970s. Scientists raised the alarm and ozone-depleting chemicals were phased out worldwide.
As a result, the upper ozone layer above the Northern Hemisphere should be completely repaired in the 2030s and the gaping Antarctic ozone hole should disappear in the 2060s, according to a scientific assessment released Monday at a conference in Quito, Ecuador. The Southern Hemisphere lags a bit and its ozone layer should be healed by mid-century.
Popular Science reports:
“Generally, it’s good news,” says Paul Newman, co-chair of the new assessment and chief scientist of earth sciences at NASA Goddard Space Flight Center. Ozone-depleting gases are decreasing and have continued to fall since the mid-1990s. “The projections into the future are pretty positive as long as parties continue to comply with the Montreal Protocol.”
That’s not to say there aren’t any flies in the ointment, Newman says. Certain ozone-depleting substances like chlorofluorocarbon-11 (CFC-11) are decreasing from the atmosphere more slowly than projected. Two independent networks have confirmed an uptick of emissions over eastern Asia since 2012, though their exact origins are still being investigated.
That’s troubling because compounds including CFC-11 are banned under the Montreal Protocol and persist in the atmosphere for decades. If someone is releasing them today, they’ll continue to do damage for generations to come.