Fwd: Re: Ozone layer could develop hole over Britain, scientists warn
--- In email@example.com, "Pat Neuman" <npat1@j...> wrote:
The ozone layer "is weakened from being attacked by CFCs and other
ozone-destroying pollutants, more radiation gets through to cause skin
cancer and cataracts, damage crops and kill the plankton that are the
basis of marine life."
My comment: The ozone layer thins as temperatures in the stratosphere
decrease. Temperatures in the stratosphere decrease as greenhouse
gases in the troposphere get heavier. As global warming worsens more
radiation gets through to cause skin cancer, ... kill the plankton
that are the basis of marine life. Thus, a thinned ozone layer may
have contributed to previous global warming extinctions (late Permian
250 mya, Cenomanian 100 mya, Paleocene/Eocene 55 mya) - due to very
cold stratospheric conditions, with non-anthropogenic ozone-destroying
elements that existed at some level of concentration in the
stratosphere during pre-human eras ... even water vapor can be an
> --- In firstname.lastname@example.org, janson1997 wrote...
Ozone layer could develop hole over Britain, scientists warn
Destruction of protective gas means greater risk of skin cancer and
cataracts. Geoffrey Lean reports
06 March 2005
Scientists will tomorrow fly a spy plane high into the world's
protective ozone layer, amid increasing fears that it may be about to
develop a hole over Britain and northern Europe.
The old Russian Cold War plane will take off from near Munich in a
EU-funded mission to check reports that the stratosphere over the
northern hemisphere faces rapid ozone destruction over the next few
weeks. If the hole developed, people living under it would be at
increased risk of skin cancer and cataracts, the main cause of blindness.
The danger - which will also be assessed by scientists meeting in
Zurich this week - has been provoked by the coldest winter on record
about 12 miles above the Arctic, setting up ideal conditions for the
destruction of the ozone layer. It is linked with global warming - as
the atmosphere nearer the Earth warms, the stratosphere cools.
The ozone layer - a scattering of the blue-tinged gas through the
21-mile deep stratosphere which is so thin that if collected together
it would form a girdle round the Earth no thicker than the sole of a
shoe - screens out harmful ultraviolet radiation from the sun.
Without it, no terrestrial life would be possible. But, as it is
weakened from being attacked by CFCs and other ozone-destroying
pollutants, more radiation gets though to cause skin cancer and
cataracts, damage crops and kill the plankton that are the basis of
For over 20 years, a hole as big as the US and as high as Mount
Everest has opened up over Antarctica every southern spring. But,
since the continent is almost entirely uninhabited, the hole has posed
little danger to human health - though skin cancer rates in southern
Chile, the only populated area under the hole, are three times as high
For just as long, scientists have feared that a similar hole would
open up over the Arctic, with serious implications for human health
since it would be over densely populated areas in Britain, northern
Europe, North America and Russia. So far, it has not formed largely
because the Arctic does not get as cold as the Antarctic. But this
year temperatures have been lower than at any time since records began
and there are more special "polar stratospheric clouds" - essential to
the process of ozone depletion - than at any time since pollution
began threatening the ozone.
The EU says: "The concern is that the Arctic appears to be moving into
Antarctic-like conditions, which will result in an increase in
ultraviolet radiation levels that will have consequences on human
health in northern hemisphere countries."
Dr Neil Harris of the European Ozone Research Co-ordinating Unit in
Cambridge says ozone levels in the Arctic are 40 per cent lower than
normal for this time of year. But scientists are divided on the
likelihood of a hole developing. The crunch will come in the next few
weeks, when sunlight - which plays a key role in destruction - returns
after the dark Arctic winter.
If the hole does form, the risk to people will depend on weather
conditions and other local factors, Dr Harris says. For example,
clouds will shield people from radiation, while sunny days will expose
them to it. But, even at its worst, the depletion is likely to be only
half as severe as over Antarctica.
While the intensely cold "vortex" that forms the hole stays in the
same place in Antarctica, in the northern hemisphere it wanders about.
At the moment, it is over northern Europe, including Britain.
--- End forwarded message ---