Emissions of an ozone-depleting fire retardant are increasing at a rate of approximately 200 tons a year, according to an atmospheric researcher at Australia's Commonwealth Scientific and Industrial Research Organization. In fact, based on measurements made in the atmosphere in Tasmania, the emissions of halon-1211 are 50 percent greater than previously thought, said Paul Fraser. Based on calculations from the United Nations' Montreal Protocol on Substances that Deplete the Ozone Layer, an agreement to eliminate substances destructive to the ozone layer and signed by 165 countries, it was assumed that halon-1211 had peaked in 1988. Since 1998, however, emissions have risen by about 25 percent.
Current emissions make it the most damaging of the halons.
Fraser and his colleagues from the United Kingdom measured halon levels in the Australian science agency's archive of pristine air collected at the Cape Grim baseline air pollution station in north-western Tasmania. Halons are now responsible for about 20 percent of global ozone destruction. China is responsible for about 90 percent of the world's production of halon-1211. Under the Montreal Protocol, developing countries such as China have until the year 2010 before they must completely phase out halon production. Montreal Protocol calculations based on production data indicate that halon levels in the air will stabilize during the next few years.