Ozone layer recovery will take longer
Pastor Dale Morgan
Scientists: Ozone layer recovery will take longer*
Friday, August 18, 2006 Posted: 1407 GMT (2207 HKT)
GENEVA, Switzerland (AP) -- The atmosphere will take up to 15 years
longer than previously expected to recover from pollution and repair its
ozone hole over the southern hemisphere, the United Nations' weather
organization said Friday.
Thinning in the ozone layer -- due to chemical compounds leaked from
refrigerators, air conditioners and other devices -- exposes the Earth
to harmful solar rays. Too much ultraviolet radiation can cause skin
cancer and destroy tiny plants at the beginning of the food chain.
Scientists said Friday it would take until 2065, instead of 2050 as
previously expected, for the ozone layer to recover and the hole over
the Antarctic to close.
"The Antarctic ozone hole has not become more severe since the late
1990s, but large ozone holes are expected to occur for decades to come,"
ozone specialist Geir Braathen told reporters in summarizing a new
report by the World Meteorological Organization and the U.N. Environment
Program. The report will be released next year.
The ozone hole, a thinner-than-normal area in the upper stratosphere's
radiation-absorbing gases, has formed each year since the mid-1980s at
the end of the Antarctic winter in August, and generally is at its
biggest in late September.
Experts said they extended the projected recovery because
chlorofluorocarbons, or CFCs, would continue to leak into the atmosphere
from air conditioners, aerosol spray cans and other equipment for years
to come.
But there was cause for celebration, they said, noting a decline in CFCs
in the first two atmospheric layers above Earth.
"The level of ozone-depleting substances continues to decline from its
1992-1994 peak in the troposphere and the late 1990s peak in the
stratosphere," WMO secretary-general Michel Jarraud said in a statement.
Less of these chemicals are used every year, he said, after 180
countries in 1997 committed to reducing CFCs under the Montreal Protocal.
"This shows that the Montreal Protocol is effective and is working," he
said.
Last year, the ozone hole reached about 27 million square kilometers (10
million square miles) on September 20 -- just below its largest size in
2003 of about 29 million square kilometers (11.2 million square miles),
WMO experts said.