With regard to CFCs and ozone depletion, Ruth Weiner mentioned the McElroy et. al. 1979 paper in Science showing the correlation between CFC production and ozone depletion. I would like to add, and I'm sorry I do not have the exact reference - but it also appeared in Science- that a study about 2-5 years ago showed a vertical concentration profile of CFCs, CFC break down products due to UV, and ozone through the atmosphere. The results showed a definite increase in CFC breakdown products and corresponding decreased in ozone concentration. This was definite proof that the postulated ozone depletion mechanism demonstrated in the lab actually worked in the atmosphere. As far as I can see, this case is closed, the culprit is identified, end of story.
With regard to global climate change, I have followed the arguments since the early '70s when it was discussed in my meteorology class at Michigan. To assume that humans are puny and have no input into global climate change is, in my estimation, a bit off base. Yes there are natural variations. However, the global biogeochemical cycles operate at some rate which may vary. However, when in the period of 100 years you dump back into a fairly stable system the carbon that has been sequestered in fossil fuel over millions of years, there has got to be some repercussions. They aren't all good. Sure plants love CO2. However not all plant like it to the same degree. It depends on the photosynthetic mechanism used. Ecosystems will not adapt to rapid rates of change.
Back in the 70s someone postulated that increased warming would bring on a new ice age because of the increase transfer of water vapor to the polar regions. The latest AGU meeting has had several papers on "snowball" earth, with evidence that the earth did, at one or several times in the past, completely freeze over. And it did so within a short time. Wallace Broecker at Columbia has published studies of ocean currents. He believes that these currents can be easily affected by global temperature increases and thereby change the distribution of heat around the globe. There are no easy solutions . As someone once said - for every difficult question there is an easy answer which is wrong.
as always, my opinions and not necessarily those of my employer
Kjell Johansen, PhD
Environmental Specialist
Point Beach Nuclear Plant
Two Rivers, WI
kjell.johansen@wepco.com
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