Ozone treaty tightened, CFC substitutes controlled

Abstract

Representatives of more than 80 nations meeting in Copenhagen have agreed to strengthen the Montreal Protocol on Substances That Deplete the Ozone Layer. The conference decided to move up the phaseout deadlines for chlorofluorocarbons (CFCs) and some other halogenated compounds. And it set restrictions, for the first time, on use of hydrochlorofluorocarbons (HCFCs), which are replacing CFCs in many applications. However, the delegates failed to agree to phase out production of methyl bromide. That agricultural fumigant recently has been determined to be the major source of ozone-destroying bromine in the stratosphere. When the landmark Montreal treaty was first negotiated in 1987, the goal was to cut CFC production 50% by 1998, and to freeze the growth in output of the bromine-containing CFCs known as halons. The London amendments of 1990 to the treaty set phaseout dates for CFCs and halons, and added controls on methyl chloroform and carbon tetrachloride. But the bad news about ...