The Coastal Post - June, 1998

Worse Ozone Depletion On The Way; May Recover By 2060-Maybe Not!

By Jim Scanlon

The Stratospheric Ozone Layer will be considerably depleted over the next twenty years before slowly reverting to the "normal" levels around 2060. That is, if all goes well, and nothing "new" comes along, according to scientists at the Goddard Institute for Space Studies at Columbia University. Severe depletion will continue, even if the Montreal Protocol, which bans the use of substances that deplete ozone, is strictly honored by all the nations of the earth, and atmospheric levels of chlorine and bromine drop to lower levels.

Drew Shindell (remember that name), David Rind and Patrick Lonergan, writing in the April 9, 1998 issue of Nature, the British International Journal of Science, note that the chemical reactions that deplete ozone are very sensitive to temperature and are much more efficient in cold air that allows frozen water and acid to form. As heat trapping gases like CO2 build up in the lower atmosphere, they prevent heat from going further up into the stratosphere thereby cooling that layer.

While scientists have not been able to accurately measure the expected warming of the highly changeable lower atmosphere and confirm convincingly the reality of the "Greenhouse Effect", they have detected a measurable cooling of the stratosphere, where most of the ozone is. So less chlorine will go further in destroying ozone as the stratosphere cools. This part seems clear and certain.

But that is not the worst of it. Shindell and his colleagues have constructed a computer model which seems to explain the observed absence of springtime atmospheric waves which warm the north polar region. The absence of springtime warming isolates, stabilizes, cools and prolongs the polar vortex until sunlight hits it and destroys ozone. There have been successive "ozone holes" over the Arctic since 1993. This is fact. Shindell and his colleagues now have a plausible, testable theory to explain these facts, and it links global warming with more intense ozone depletion and a change in how our atmosphere moves.

Unsurprisingly, the major print and broadcast media have not reported the massive ozone depletions over the Arctic since 1993, even though reputable scientists have begun to use the term "Arctic Ozone Hole". (Nature itself has not yet mentioned these depletions in its news section.) The severe ozone depletions in uninhabited "Antarctica are well known. The Southern Hemisphere will be more seriously affected for a longer period of time.

The Arctic Ozone Hole is, to be sure, much different from its older, larger, deeper, longer lasting sibling which forms each springtime over Antarctica-but they are clearly related-and the large human populations living around the Arctic, and the reflective snow and ice that covers the land mass during March and April, magnify the consequences enormously.

But the most momentous possibility would be that the researchers from Columbia are right in their assertion that global warming and ozone depletion together, are changing the temperature structure of the atmosphere and weakening planetary atmospheric waves that warm the Arctic. This would be akin to the discovering that the Gulf Stream, which keeps Western Europe from freezing over, had stopped, or slowed down!

Mostly there is not a broad consensus that climate change, on a global scale, is occurring as we have accurate climate records that go back less than 200 years. The new observations seem to confirm that global change is happening, here, right now-and with a vengeance!

Already European and American scientists are working on a program called SOLVE (Stratospheric Ozone Loss and Validation Experiment). The program will document the loss of Arctic ozone with ground based instruments, U-2 flights and satellite observations during the coming winter of 1998-1999. (You won't find this information in the media-except of course the Coastal Post!).

To get an idea of the populations most immediately affected, take a look at a globe and find 50 degrees south, the outer limit of the Antarctic Ozone Hole. Perhaps 200 to 300 thousand people live within the tiny land area there. Now look north of 50 degrees north and you will see an area in which some 300 to 400 million people live and work.

Normally, there is been much more ozone over the Arctic than the Antarctic to start with, so a, say, fifty percent depletion would still leave the north a little better off than the south with respect to increased levels of ultraviolet radiation on the surface.

But the south is little more than ocean while the north is land usually covered in springtime with snow and ice which efficiently reflect ultraviolet. The people who live in the north are mostly light skinned, the ones most seriously affected by high levels of ultra violet sunlight.

Since the fair skinned, blue eyed, snow and ice loving Norwegians and Swedes are the ones who award Nobel Prizes, there may be some sad consolation for the Goddard scientists if their somber hypothesis receives support from further observations.

Otherwise their work may not get much attention, as their powerful neighbors in New York on Wall Street don't take kindly to bad, unnerving news. "The Media" knows "The Economy" powered by "The Market", are strange creatures which can stampede unexpectedly when frightened. Where ignorance is bliss, tis folly to be wise!

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