Man-made gases are depleting the ozone layer, scientists warned. According to researchers at Leeds University in northern England, ‘very short-lived substances’ (VSLS) are chewing up the earth’s protective layer that protects us from harmful ultraviolet rays coming from the sun.
Ozone layer lies in the stratosphere and has been steadily depleting due to emission of man-made chlorine fumes including chlorofluorocarbons (CFCs). Thus, to restore the ozone layer, United Nations treaty stood up in 1987 and made Montreal Protocol that limits every nation on production of CFCs. These CFCs are used as a coolant in refrigerators and when exposed to the atmosphere they react with ozone layer that constitutes 3 oxygen molecules and breaks it into two oxygen molecules and one nascent oxygen thus, breaking the ozone structure.
Now scientists claim that dichloromethane (a man-made VSLS) used as a substitute for ozone-depleting gases outlawed by Montreal law is also doing the same – depleting ozone layer. VSLS aren’t outlawed by Montreal law as they haven’t contributed much to depletion of the protective layer in the past, and it’s production has increased dramatically in recent few years.
For the study, researchers analysed raw data of two decades provided by the US National and Atmospheric Administration (NOAA). Several simulations and computer models suggest that these short-lived substances that break down within six months account for about 12.5 percent of total ozone loss in the Antarctica region, where ozone depletion are most significant.
“Dichloromethane appears to be one of the most abundant man-made VSLS that we know of,” said lead investigator Ryan Hossaini said.. “Our study shows that the atmospheric concentration of dichloromethane has increased dramatically in recent years, at some locations its atmospheric concentration has doubled since the late 1990s.”
While comparing to CFCs effect of VSLS is small. Ozone layer protects us from ultraviolet rays coming from the sun that causes several skin diseases including skin cancer and cataract.Tags: CFCs, Ozone, VSLS