Antarctic ozone hole may persist 20 years longer than expected

Remember that hole in the ozone over Antarctica? The one we fixed? Big environmental success story? Turns out it may take roughly two decades longer than expected for it to fully heal — until around 2065, instead of 2040 to 2050 — because sizable amounts of chlorofluorocarbons are still being released into the atmosphere by industrialized nations. Researchers reported this week that the U.S. and Canada are responsible for about 15 percent of total global CFC emissions, even though CFC production in industrialized nations has been phased out under the 1987 Montreal Protocol. The scientists say they underestimated how long already-produced CFCs would remain a factor; the chemicals continue to leak from equipment like old refrigerators and air-conditioners. And the widely used pesticide methyl bromide — another virulent ozone-destroyer — was to be phased out in industrial nations this year under Montreal, but the U.S. is leading efforts to keep it in use.