Antarctic ozone hole could close by 2050 - scientist

Paul Fraser with the Australian government\'s Commonwealth Scientific and Industrial Research Organisation (CSIRO) said he had measured a decline in ozone-destroying gases since 2000. \"The major culprit in the production of the ozone hole is CFCs and they have started to decline in the lower atmosphere,\" Fraser told Reuters in an interview. \"We think the ozone hole will recover by about 2050,\" said Fraser, from CSIRO\'s atmospheric division and a lead author on a U.N. report on the ozone layer released this week. The report said ozone-depleting gases in the upper atmosphere had ben at or near their peak in 2000, but the world was making steady progress towards the recovery of the ozone layer. It said scientific data showed levels of ozone-depleting gases in the lower atmosphere were \"declining, albeit slowly\", but the ozone would be vulnerable for a decade. The ozone layer is essential for life on earth, shielding the earth from the harmful ultraviolet-B radiation from the sun and completely screening out lethal UV-C radiation. Chlorine from chlorofluorocarbons (CFCs) is responsible for destroying part of the ozone layer over Antarctica. CFCs have been widely used since the 1930s in refrigerators, and air conditioners and remain in the atmosphere for decades. Under the 1987 Montreal Protocol, developing countries committed themselves to halving consumption and production of CFCs by 2005 and to achieving an 85 percent cut by 2007. Fraser, who monitors CFCs from Australia\'s southern island of Tasmania, said that in 1950 the atmospheric level of chlorine from CFCs had been zero, rose to a peak of 2.15 parts per million in 2000, but had fallen one percent a year since 2000. \"We are now at a point where the atmosphere can actually remove CFCs faster than they are being released into the atmosphere,\" said Fraser, adding the actual decline in CFCs had not been measured when the U.N. report was compiled in 2000. The U.N. report, the latest in a series of four-yearly reports reviewing the ozone layer since the Montreal Protocol, said the reduction in CFCs proved the protocol was working. But the report warned that the hole over Antarctica would only close fully if countries continued to adhere to the protocol and if there were no other factors adversely affecting the ozone layer like a major increase in greenhouse gases. \"These results confirm that the Montreal Protocol is achieving its objectives. During the next decades we should see a recovery of the ozone layer,\" said the report. Story by Michael Perry REUTERS NEWS SERVICE