1995 UN Ozone report
GENEVA (AP) -- The hole in the earth's ozone layer is growing faster than
ever and is already twice the size it was this time last year, the U.N.
weather agency said Tuesday.
Ozone, a gas in the stratosphere, prevents harmful ultraviolet radiation
from reaching the earth. Its depletion, caused in large part by industrial
chemicals, is believed to increase the incidence of skin cancer and
cataracts.
The hole, first observed over Antarctica in the 1980s, has reappeared each
September and October since then. With the onset of winter in the polar
region, temperatures plung in the stratosphere and hasten ozone depletion.
The hole is getting bigger despite a reduction in ozone-destroying
chemicals such s chlorine and bromine because these chemicals have a life
of 60 to 100 years.
So far the hole has expanded to 3.9 million square miles -- roughly the
size of Europe -- according to the World Meteorological Organization.
At that rate, the hole could surpass the record 24 million square miles
it reached at the end of September last year, the U.N. agency said.
The accelerated spread of the hole has surprised but not alarmed experts,
who predict the ozone layer will get even worse before it recovers.
"From the end of July through August and early September ozone levels in
this polar region have depleted by an average of 1 percent a day... more
rapidly than ever before," said Rumen Bojkov, special adviser on ozone to
the agency.
"Every 1 percent drop in ozone means roughly 1.3 percent to 1.5 percent
more ultraviolet radiation reaching the surface," said Bojkov.
He said each 1 percent increase in ultraviolet radiation is thought to
increase chances of skin cancer and eye cataracts by 2 percent.
The U.N. weather agency has been monitoring ozone levels in Antarctica
for the last 40 years. Already in August, the region had 30 to 35 percent
less ozone than in 1957, before depletion began.
The ozone layer also has deteriorated over Europe and North America, but
to a lesser extent. The agency says ozone levels over Europe and North
America have diminished 10 percent to 15 percent since 1957. At the same
time, ultraviolet radiation has increased 13 percent to 15 percent.
"This is something surplus to the normal ultraviolet everyone is getting,
" Bojkov said. "It is undesirable because it is a cumulative. Everyone
collects more radiation over a lifetime. It is not dangerous at the
moment but it could be, depending on how long such conditions continue."
Without the Montreal Protocol, the 1987 agreement by countries to reduce
worldwide use of ozone-destroying chemicals, Europe and North America
would have over 35 percent more ultraviolet radiation by now, he said.
The organization expects the ozone decline to become more severe the next
10 years, reducing levels over Europe and North America by at least
another 5 percent.
After that, the depletion is expected to slow down before starting to
recover around 2040. "We expect ozone levels to recover, but not before
2050 or 2070, and that is if everyone sticks to the rules," said Bojkov.
ever and is already twice the size it was this time last year, the U.N.
weather agency said Tuesday.
Ozone, a gas in the stratosphere, prevents harmful ultraviolet radiation
from reaching the earth. Its depletion, caused in large part by industrial
chemicals, is believed to increase the incidence of skin cancer and
cataracts.
The hole, first observed over Antarctica in the 1980s, has reappeared each
September and October since then. With the onset of winter in the polar
region, temperatures plung in the stratosphere and hasten ozone depletion.
The hole is getting bigger despite a reduction in ozone-destroying
chemicals such s chlorine and bromine because these chemicals have a life
of 60 to 100 years.
So far the hole has expanded to 3.9 million square miles -- roughly the
size of Europe -- according to the World Meteorological Organization.
At that rate, the hole could surpass the record 24 million square miles
it reached at the end of September last year, the U.N. agency said.
The accelerated spread of the hole has surprised but not alarmed experts,
who predict the ozone layer will get even worse before it recovers.
"From the end of July through August and early September ozone levels in
this polar region have depleted by an average of 1 percent a day... more
rapidly than ever before," said Rumen Bojkov, special adviser on ozone to
the agency.
"Every 1 percent drop in ozone means roughly 1.3 percent to 1.5 percent
more ultraviolet radiation reaching the surface," said Bojkov.
He said each 1 percent increase in ultraviolet radiation is thought to
increase chances of skin cancer and eye cataracts by 2 percent.
The U.N. weather agency has been monitoring ozone levels in Antarctica
for the last 40 years. Already in August, the region had 30 to 35 percent
less ozone than in 1957, before depletion began.
The ozone layer also has deteriorated over Europe and North America, but
to a lesser extent. The agency says ozone levels over Europe and North
America have diminished 10 percent to 15 percent since 1957. At the same
time, ultraviolet radiation has increased 13 percent to 15 percent.
"This is something surplus to the normal ultraviolet everyone is getting,
" Bojkov said. "It is undesirable because it is a cumulative. Everyone
collects more radiation over a lifetime. It is not dangerous at the
moment but it could be, depending on how long such conditions continue."
Without the Montreal Protocol, the 1987 agreement by countries to reduce
worldwide use of ozone-destroying chemicals, Europe and North America
would have over 35 percent more ultraviolet radiation by now, he said.
The organization expects the ozone decline to become more severe the next
10 years, reducing levels over Europe and North America by at least
another 5 percent.
After that, the depletion is expected to slow down before starting to
recover around 2040. "We expect ozone levels to recover, but not before
2050 or 2070, and that is if everyone sticks to the rules," said Bojkov.
Comments
Post a Comment