Arctic Ozone Hole Appears
by Jim Scanlon
(Coastal Post, January, 1998)
Ozone values have finally fallen so low over the north polar region of our
Hemisphere that scientists are using the term "Arctic Ozone Hole".
While not as large, or as severe as its older sibling Ozone Hole over
Antarctica, the history and extent of ozone loss during the last two
winters make it completely deserving of the name.
While the Arctic stratosphere has been much more contaminated with
industrial pollutants than Antarctica, it is normally warmer and, until
recently this has not permitted the formation of icy polar stratospheric
clouds which activate chlorine from stable compounds. This has suddenly
You, dear reader, should ask why this subject has not been reported in the
media so preoccupied with scientific uncertainty over "Global Warming" and
the conference in Kyoto.
On November 15, 1997, one of the world's most prestigious scientific
journals. Geophysical Research Letters, published eight papers in a
"Special Section: Arctic Ozone Loss in 1966-1997. The American Geophysical
Union issued two press releases which were not picked up by the media.
"How come?" one might legitimately ask.
While there is no "proof" (in the O.J. Simpson "Dream Team" legalistic
sense) that the unusual cold temperatures necessary for catastrophic
ozone depletion are connected with the cooling of the stratosphere
predicted by "global warming" models, there are no other candidates
available at present.
The existence of the infant "Arctic Ozone Hole" has been confirmed by a
large variety of satellite, balloon and ground based observations and is,
it would seem, beyond argument. What remains to be seen is if the new hole
will continue to enlarge and deepen over the next few years as the old
familiar one did.
It has often been stated that the springtime Antarctic Ozone Hole could not
get much worse because there is virtually nothing left to destroy and also
that its size was limited by the strong circumpolar winds that form a
"wall" around the icy continent. During the last two years, it did not get
bigger or deeper, but it has begun to more strongly affect populated parts
of South America and perhaps even Southern Africa.
Both "Ozone Holes" are, or course, separate and apart from the global
decline in the Ozone Layer of five percent in the Northern Hemisphere and
ten in the South. (You may feel the added strength of the sun and find that
your skin burns faster than before.)
So far, satellites have not been able to precisely measure a "warming" of
the earth's turbulent atmosphere attributable to human activities, and this
has led to aggressive opposition by energy corporations, to all attempts
to limit emissions of heat trapping gases. There may be many smoking
chimneys, but in the legal jargon that runs our lives, there is no
Whether an unequivocal "warming" is ever discovered in time enough to do
something about it, is hard to say. The stratosphere, however, is a
different thing. It is stable and doesn't change much. It changes only
slowly like the desert or high altitude ecosystems. Compounds that might
stay in the stratosphere for months or years, last days or weeks in the
There is little doubt that the stratosphere has cooled over the past
decade. The question is how cool will it get!? And will this liberate more
chlorine?. It is conceivable that even with chlorine declining
substantially, if temperatures drop enough to form icy aerosols, there
could be more chlorine available to destroy ozone. Not a pleasant
Well, what does this really mean for us? Arctic ozone levels have declined
over the past twenty years in the same way that Antarctic levels declined,
but there are differences. In the Arctic, normal springtime ozone levels
were around 500 Dobson Units, now normal values are 350 with lows of 250.
To put this into perspective, the normal Antarctic highs used to be around
350 and now sink to well under 200 with occasional lows of under 100. The
Arctic always had more to lose. Whether this loss will be felt in other
parts of the hemisphere through export of ozone poor stratospheric air
further south, remains to be seen.
All things being equal (clouds, pollution, time of day, time of year) less
ozone means more ultraviolet radiation. In South America, humans are being
affected right now (see Coastal Post December 1997). This news is being
officially ignored and/or blocked, most likely for economic reasons.
People are not dropping dead in the streets---at least not yet! But
they know something is happening and it is truly awesome to think that for
trivial, mostly cosmetic reasons, we have accidentally changed the light
from the sun. It will get worse and we can't do anything about it except
In the North there are millions of people living at high latitudes and in
the months of low ozone, March and April, much of the land is covered with
snow which effectively double the amount of ultraviolet radiation by
reflection. Skiers know what normal sunlight on snow can do to unprotected
skin, particularly light skin. An increase in the shorter, more powerful
wavelengths of ultraviolet could be very dangerous.
While human health is only one aspect of the harmful effects of ozone
depletion, it is the one most likely to surface as a problem because
humans talk and can complain---whereas, invertebrates and wild animals
only suffer and die in silence.
Life may get a little more difficult for the people of the North, and it is
perhaps no accident that Canadians contributed two of the eight papers
which appeared in Geophysical Research Letters.
So far, scientists have tended to distance themselves from the
environmental effects of ozone depletion and climate warming, preferring
to view these effects as coming, 20 or 50 or 100 years from now.
I wonders how long will it take before it is realized these problems are
with us here, there, right now, today, tomorrow, yesterday !