UN says Earth's ozone layer finally heals

By SETH BORENSTEIN

WASHINGTON (AP) – The protective ozone layer of the Earth is finally curing aerosol and coolant damage, says a new UN report.

The ozone layer has thinned since the late 1970s. Scientists have sounded the alarm and ozone – depleting chemicals have been eliminated around the world.

As a result, the upper ozone layer above the northern hemisphere is expected to be fully repaired in the 2030s and the gaping hole in Antarctic ozone is expected to disappear in the 2060s , according to a scientific badessment released Monday at a conference in Quito, Ecuador. The southern hemisphere is a little behind and its ozone layer should be healed in the middle of the century.

"This is very good news," said report co-chair Paul Newman, Earth Sciences Expert at NASA's Goddard Space Flight Center. "If ozone – depleting substances continued to increase, we would have had enormous effects. We stopped that.

At altitude, ozone protects the Earth from ultraviolet rays that cause skin cancer, crop damage and other problems. The use of synthetic chemicals, called chlorofluorocarbons (CFCs), which give off chlorine and bromine, began to eat away at ozone. In 1987, countries around the world agreed in the Montreal Protocol to phased out CFCs and companies proposed alternatives for aerosol cans and other uses. said Newman. Since 2000, it has increased by about 1 to 3% per decade, the report said.

This year, the hole in the ozone layer above the South Pole peaked at nearly 9.6 million square miles. That's about 16% less than the largest hole recorded – 11.4 million square miles in 2006.

The hole peaks in September and October and disappears at the end of December until the end of December. next spring in the southern hemisphere, said Newman.

the layer begins about 10 km from the Earth and extends over nearly 40 km; Ozone is a colorless combination of three atoms of oxygen.

If nothing had been done to stop the thinning, the world would have destroyed two thirds of its ozone layer by 2065, said Newman.

But this is not a complete success. However, said Brian Toon, of the University of Colorado, who was not part of the report.

"We are at a point where recovery may have begun," Toon said, noting that some ozone measurements had not yet risen.

Another problem is that new technologies have highlighted an increase in banned CFC emissions in East Asia, the report says.

By itself, the hole in the ozone layer has slightly protected Antarctica from the much larger effects of global warming. – He's warmed up but not as much as he would have probably without destroying the ozone layer, said Ross Salawitch, Maryland's atmospheric scientist and co-author. author of the report.