Emis­sions of ozone-eat­ing chem­i­cal are ris­ing de­spite global ban

Richmond Times-Dispatch - - WEATHER DESK -

WASH­ING­TON — Some­thing strange is hap­pen­ing with a banned chem­i­cal that eats away at Earth’s pro­tec­tive ozone layer: Sci­en­tists say there’s more of it — not less — go­ing into the at­mos­phere, and they don’t know where it is com­ing from.

When a hole in the ozone formed over Antarc­tica, coun­tries around the world in 1987 agreed to phase out sev­eral types of ozone-de­plet­ing chem­i­cals called chlo­roflu­o­ro­car­bons (CFCs). Pro­duc­tion was banned, emis­sions fell and the hole slowly shrank.

But start­ing in 2013, emis­sions of the sec­ond most­com­mon kind started ris­ing, ac­cord­ing to a study in Wed­nes­day’s jour­nal Na­ture. The chem­i­cal, called CFC-11, was used for mak­ing foam, de­greas­ing stains and for re­frig­er­a­tion.

“It’s the most sur­pris­ing and un­ex­pected ob­ser­va­tion I’ve made in my 27 years” of mea­sure­ments, said study lead au­thor Stephen Montzka, a re­search chemist at the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion.

“Emis­sions today are about the same as it was nearly 20 years ago,” he said.

Coun­tries have re­ported close to zero pro­duc­tion of the chem­i­cal since 2006, but the study found about 14,300 tons a year has been re­leased since 2013. Some seeps out of foam and build­ings and ma­chines, but sci­en­tists say what they’re see­ing is much more than that.

Mea­sure­ments from a dozen mon­i­tors around the world sug­gest the emis­sions are com­ing from some­where around China, Mon­go­lia and the Koreas, ac­cord­ing to the study. The chem­i­cal can be a byprod­uct in other chem­i­cal man­u­fac­tur­ing, but it is sup­posed to be cap­tured and re­cy­cled.

Ei­ther some­one’s mak­ing the banned com­pound or it is sloppy byprod­ucts that haven’t been re­ported as re­quired, Montzka said.

No ex­pla­na­tion fits the data bet­ter than new pro­duc­tion, the sci­en­tists re­port. They de­tected a spike in the dif­fer­ence be­tween at­mo­spheric lev­els in the North­ern and South­ern Hemi­spheres, sug­gest­ing fa­cil­i­ties in the highly in­dus­tri­al­ized north. They then used air pol­lu­tion mod­el­ing to back­track pos­si­ble ori­gins of the air they sam­pled, to East Asia.

An out­side ex­pert, Ross Salaw­itch, an at­mo­spheric sci­en­tist at the Univer­sity of Mary­land, is less diplo­matic. He calls it “rogue pro­duc­tion,” adding that if it con­tin­ues, “the re­cov­ery of the ozone layer would be threat­ened.”

Montzka said the pa­per de­liv­ers hard ev­i­dence of re­newed pro­duc­tion, de­spite po­ten­tial com­pli­cat­ing fac­tors, such as the vari­able move­ments of high­fly­ing air masses and the resid­ual emis­sion of CFC-11 from ma­te­ri­als that were com­mon in build­ing con­struc­tion.

The study is rare in that it may have both pro­found eco­log­i­cal and po­lit­i­cal im­pli­ca­tions. It’s dif­fi­cult to say which are more pro­nounced.

Cal­cu­la­tions done af­ter he and his col­leagues fin­ished up the pa­per sug­gest that a cou­ple of decades of CFC-11 pro­duc­tion at ob­served lev­els might de­lay by only a decade es­ti­mates of when the ozone hole will re­turn to 1980 scale — mid-cen­tury.

“The sky isn’t fall­ing,” Montzka said.

High in the at­mos­phere, ozone shields Earth from ul­tra­vi­o­let rays that cause skin can­cer, crop dam­age and other prob­lems.

Na­ture re­moves 2 per­cent of the CFC-11 out of the air each year, so con­cen­tra­tions of the chem­i­cal in the at­mos­phere are still fall­ing, but at a slower rate be­cause of the new emis­sions, Montzka said. The chem­i­cal stays in the air for about 50 years.

In­for­ma­tion from The Wash­ing­ton Post was in­cluded in this re­port.

THE AS­SO­CI­ATED PRESS

Aurora aus­tralis, also known as south­ern lights, shine near the South Pole At­mo­spheric Re­search Ob­ser­va­tory in Antarc­tica.

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