Sci­en­tists fear ozone gas cheat

The Southland Times - - World -

Emis­sions of a banned ozonede­plet­ing chem­i­cal are on the rise, a group of sci­en­tists re­ported yes­ter­day, sug­gest­ing some­one may be se­cretly man­u­fac­tur­ing the pol­lu­tant in vi­o­la­tion of an in­ter­na­tional accord.

Emis­sions of CFC-11 have climbed 25 per cent since 2012, de­spite the chem­i­cal be­ing part of a group of ozone pol­lu­tants that were phased out un­der the 1987 Mon­treal Pro­to­col.

‘‘I’ve been mak­ing these mea­sure­ments for more than 30 years and this is the most sur­pris­ing thing I’ve seen,’’ said Stephen Montzka, a sci­en­tist with the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion, who led the work.

‘‘I was as­tounded by it re­ally.’’ It’s a distress­ing re­sult for what’s widely seen as a global en­vi­ron­men­tal suc­cess story, in which na­tions – alarmed by a grow­ing ‘‘ozone hole’’ – col­lec­tively took ac­tion to phase out chlo­roflu­o­ro­car­bons.

The find­ing seems likely to prompt an in­ter­na­tional in­ves­ti­ga­tion into the mys­te­ri­ous source.

Of­fi­cially, pro­duc­tion of CFC11 is sup­posed to be at or near zero – at least, that is what coun­tries have been telling the United Na­tions body that mon­i­tors and en­forces the pro­to­col.

But with emis­sions on the rise, sci­en­tists sus­pect some­one is mak­ing the chem­i­cal in de­fi­ance of the ban.

‘‘Some­body’s cheat­ing,’’ said Dur­wood Zaelke, founder of the In­sti­tute for Gover­nance and Sus­tain­able De­vel­op­ment and an ex­pert on the Mon­treal Pro­to­col, in a com­ment on the new re­search.

‘‘There’s some slight pos­si­bil­ity there’s an un­in­ten­tional re­lease, but ... they make it clear there’s strong ev­i­dence this is ac­tu­ally be­ing pro­duced.’’

But for now, the sci­en­tists don’t know ex­actly who, or where, that per­son would be.

A US ob­ser­va­tory in Hawaii found CFC-11 mixed in with other gases that were char­ac­ter­is­tic of a source com­ing from some­where in east Asia, but sci­en­tists could not nar­row the source down any fur­ther.

Zaelke said he was sur­prised by the find­ings, not just be­cause the chem­i­cal has long been banned, but also be­cause al­ter­na­tives al­ready ex­ist, mak­ing it hard to imag­ine what the mar­ket for CFC-11 to­day would be.

The re­search was led by re­searchers with the US Na­tional Oceanic and At­mo­spheric Ad- min­is­tra­tion with help from sci­en­tists in the Nether­lands and the United King­dom. Their re­sults were pub­lished in the jour­nal Na­ture.

There is a small chance that there is a more in­no­cent ex­pla­na­tion for the rise in CFC-11 emis­sions, the sci­en­tist say.

They con­sid­ered a range of al­ter­na­tive ex­pla­na­tions for the growth, such as a change in at­mo­spheric pat­terns that grad­u­ally re­move CFC gases in the strato­sphere, an in­crease in the rate of de­mo­li­tion of build­ings con­tain­ing old residues of CFC-11, or ac­ci­den­tal pro­duc­tion.

But they con­cluded these sources could not ex­plain the in­crease, which they cal­cu­lated at about 13 bil­lion grams per year in re­cent years.

Rather, the ev­i­dence ‘‘strongly sug­gests’’ a new source of emis­sions, the sci­en­tists wrote.

‘‘I’ve been mak­ing these mea­sure­ments for more than 30 years and this is the most sur­pris­ing thing I’ve seen.’’

Stephen Montzka, Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion

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