Earth’s ozone layer is heal­ing–UN

Cebu Daily News - - WORLD -

Wash­ing­ton — The 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.

“It’s re­ally good news,” said re­port co-chair­man Paul New­man, chief Earth sci­en­tist at NASA’s God­dard Space Flight Cen­ter. “If ozone-de­plet­ing sub­stances had con­tin­ued to in­crease, we would have seen huge ef­fects. We stopped that.”

High in the at­mos­phere, ozone shields Earth from ul­tra­vi­o­let rays that cause skin cancer, crop dam­age and other prob­lems. Use of man-made chem­i­cals called chlo­roflu­o­ro­car­bons (CFCs), which re­lease chlo­rine and bromine, be­gan eat­ing away at the ozone. In 1987, coun­tries around the world agreed in the Mon­treal Pro­to­col to phase out CFCs and busi­nesses came up with re­place­ments for spray cans and other uses.

At its worst in the late 1990s, about 10 per­cent of the up­per ozone layer was de­pleted, said New­man. Since 2000, it has in­creased by about 1 to 3 per­cent per decade, the re­port said.

This year, the ozone hole over the South Pole peaked at nearly 24.8 mil­lion square kilo­me­ters. That’s about 16 per­cent smaller than the big­gest hole recorded — 29.6 mil­lion square kilo­me­ters in 2006.

The hole reaches its peak in Septem­ber and Oc­to­ber and dis­ap­pears by late December un­til the next South­ern Hemi­sphere spring, New­man said.


This com­bi­na­tion of images made avail­able by NASA shows ar­eas of low ozone above Antarc­tica on Septem­ber 2000, left, and Septem­ber 2018.

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