The Earth’s protective ozone layer is recovering at such a rate that it will completely restore the hole over Antarctica in about 43 years, according to a United Nations report cited by Al Jazeera.

A four-year scientific assessment found that recovery has been going on for more than 35 years after every country in the world agreed to stop producing ozone-depleting chemicals in the Earth’s atmosphere.

This layer protects the planet from harmful radiation linked to skin cancer, cataracts and crop damage.

“In the upper stratosphere and the ozone hole, we see things getting better,” said Paul Newman, co-chair of the scientific assessment.

Progress has been slow, according to a report presented Monday at the American Meteorological Society’s convention in Denver.

The global average amount of ozone in the atmosphere above 30 km will not return to pre-1980 levels until around 2040, the report said. And in the Arctic, it will return to normal only in 2045.

According to the report, the huge hole in the layer that forms over Antarctica every year will not be fully repaired until 2066.

Scientists and environmentalists around the world have long hailed efforts to “cure” the ozone hole as one of humanity’s greatest environmental victories.

The initiative was born out of a 1987 agreement called the Montreal Protocol, which banned a class of chemicals often used in refrigerants and aerosols.

“Action on ozone sets a precedent for climate action,” World Meteorological Organization Secretary-General Petteri Taalas said in a statement.

“Our success in phasing out ozone-depleting chemicals shows us what can and must be done — urgently — to move away from fossil fuels, reduce greenhouse gases and limit global warming,” Taalas added.

Four years ago, positive signs were reported for the ozone layer, but they were minor and more tentative.