'Ozone Friendly' Chemicals Actually Damaging to Ozone Layer

YEREVAN, FEBRUARY 17, ARMENPRESS: The growing production ofozone-friendly chemicals (HFCs) that have a short life span is destroying the ozone layer withan extremely dangerous pattern that is almost four times more efficient atinfluencing climate, a new scientific report released Monday suggests, Armenpress reports, citing the Nature Geoscience.

In the report, 'Efficiency ofshort-lived halogens atinfluencing climate throughdepletion ofstratospheric ozone' and published inthe journal Nature Geoscience, the scientists found that the atmospheric abundance ofone ofthese ‘very short-lived substances’ (VSLS) is growing rapidly, and the industrial production ofVSLS is not controlled bythe United Nations Montreal Protocol because historically these chemicals have contributed little toozone depletion.

“Due totheir short atmospheric lifetimes, VSLS break downand destroy ozone inthe lowermost part ofthe stratosphere. This is important, asa molecule ofozone lost inthis region has a far larger impact onclimate thana molecule destroyed athigher altitudes bylonger-lived gases,” the study’s lead author Dr. Ryan Hossaini, fromthe School ofEarth and Environment atthe University ofLeeds said.

VSLS can have natural and industrial sources.Naturally-emitted VSLS, such asseaweed inthe ocean accounts foraround 90 percent ofthe ozone layer depletion, butthe dangerous trend is the increase inman-made VSLS compounds.

According tothe study, there has been a rapid increase inatmospheric concentrations ofdichloromethane, a man-made VSLS used ina range ofindustrial processes.

“It is uncertain what is driving this growth. However, it could be partly due tothe fact that dichloromethane is used inthe manufacturing process ofsome HFCs, the 'ozone-friendly' gases which were developed toreplace CFCs. This would mean, ironically, that production ofozone-friendly chemicals is actually releasing some ozone-destroying gases intothe atmosphere,” Dr. Hossaini said.

Unlike chlorofluorocarbons (CFCs) and hydrofluorochlorocarbons (HCFCs), HFCs are not banned bythe Montreal Protocol.Thus the use ofHFCs has been increasing sincethe 1990s. The study concludes that if this increase is not halted, it could offset some ofthe benefits tothe Ozone Layer that the Montreal Protocol provides.

The stratospheric ozone layer is a fragile shield ofgas that protects the Earth fromharmful ultraviolet rays fromthe sun. The Montreal Protocol onSubstances that Deplete the Ozone Layer is an international treaty designed toprotect the ozone layer byphasing outthe production ofnumerous substances that are responsible forits depletion.

The treaty came intoforce in1989 and is ratified by196 countries, including Russia. Without the Montreal Protocol and associated agreements, atmospheric levels ofozone depleting substances could have increased tenfold by2050, according tothe United Nations Environment Programme.