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Antarctic Ozone Hole Leveling Off
twistedfuck writes: "An Irish Time article reports that the size of the hole in the antartican ozone layer is levelling off and should begin reducing in size. It seems like it should be welcome news but it is tempered by the fact that more UV radiation will reach the southern hemisphere this year because the hole will persist longer. Unfortunately I can not find any details regarding the NOAA report on their website." Update: 11/06 17:31 GMT by H :Thanks to Isaac Lewis, NOAA Sysadmin and Slashdot reader, for pointing out more information, as well as pointing out the ozonelayer site.
Are we to believe that this reduction in size is a result of global regulation of CFCs, or could it possibly just be part of a natural cycle? Too bad we didn't get satellites before styrofoam.
You're right, we're not going to destroy the earth in a little over two centuries. However, we are making great strides toward making the earth very, very hard to inhabit for humans (and a number of other critters). If we just let things keep on going as they are and use up all of our fossil fuels and spew pollution into the air, land, and sea, the earth won't be a great place to live for us. But you better believe Mother Nature wouldn't care one bit if humans disappeared forever. Earth itself would keep on living, with other species remaining and probably a lot happier that we're gone.
Sunlight naturally converts some oxygen to ozone in the upper atmosphere. Problem is that when CFCs and other chemicals are present, they eat up ozone far faster than it is typically produced.
Ozone is harder to produce and easier to break down when it is cold, which is one reason ozone is at its lowest levels over the poles in winter (also when there is a deficit of sunlight). The poles are also especially vulnerable because global wind patterns circle around them rather then refreshing the air. Even the most stubborn air pollutants will break down or become absorbed by the environment if we stop pumping them out and give the Earth time to get back to normal.
Which volcano in the Phillipines poured out CFCs? I'd be very interested in hearing about a volcano that poured out chemicals that do not naturally occur! CFCs are manmade - they are no naturally occuring CFCs.
The hazards we now associate with CFCs were discovered in the 1960s when a British chemist (Lovelock) was interested in tracing the motions of air masses. He was using CFC's to do so, as they were ideal for tracing air motions, being chemically stable and not naturally-occurring (they are only man-made) so their presence in an air mass could not be confused with CFC's coming from natural sources.
Perhaps you are thinking of the theory that volcanic chlorine caused ozone depletion? There are a number of problems with this:
(1) There was significant O3 loss in the 1980's, but no major volcanic activity then.
(2) There has been major volcanic activity since O3 monitoring began in the 1950's, but it was not necessarily associated with declines in O3. That is, O3 losses and volcanic activity appear to be uncoupled in time (lack temporal consistency)
(3) Measures of hydrogen chloride in the stratosphere after the relatively recent eruptions of Mt. Pinatubo and El Chicon showed less than a 10% increase in stratospheric HCl following those eruptions, while stratospheric HCl has increased steadily across recent years. Furthermore, it is estimated that 1% of the Cl released by the eruption of Mt. Pinatubo Cl made it to the stratosphere, judged by the increase in HCl in the stratosphere following the eruption and the estimated release of Cl by the volcano.
(4) Stratospheric hydrogen fluoride has also increased steadily in parallel with HCl, as would be consistent with CFC sources.
(5) Much of the HCl produced by volcanoes (or Cl from sea salt) is injected into the troposphere and very little of that makes it to the stratosphere, as it is washed out first. Volcanic emissions include abundant water vapor, and HCl and NaCl are quite soluble in water, while CFC's are not.
(6) Most of the HCl that does make it to the stratosphere is rapidly washed out -- that is the major removal mechanism for Cl from the stratosphere.
(7) After volcanic eruptions, scientists find enriched sulfate in ice caps, suggesting that the eruptions inject sulfate into the stratosphere, where it gets widely distributed before being washed out. However, ice caps are not enriched with Cl following volcanic eruptions, suggesting that most Cl doesn't make it to the stratosphere where it could get dispersed as sulfate does.
Ok, here's the deal:
Stratospheric ozone is created by bombarding normal, happily breathable O2 mollecules with ultraviolet light, splitting the O2 into a pair of O1's. These O1's eventually bump into another O2 mollecule and create O3. Big woop.
Where there is solar UV light, you'll probably see some ozone popping up. Since the Antarctic Desert is in the dark for a good chunk of the year, you'll discover a not-too-surprising lack in stratospheric ozone over winter and well into the Spring. Also not surprisingly, we have an ozone hole over the north pole.
Over the north pole, of course, there isn't quite as extreme a desert as over the south, and there are more large land masses nearby to carry air better.
Back in the 30s when the first weather measurements were taken in Antarctica they found almost identical levels of UV light hitting them as during a modern winter. Greenies prefer to depend on climactic models rather than empirical evidence these days, however, so their multi-million dollar research is stating the problem is getting bigger, even if someone else's multi-thousand dollar research is saying the opposite.
The ozone hole is the result of too many people putting faith in government, who can't predict the future more than a few weeks down the road, and weather men, who can't predict the future more than a few days down the road, and expecting their government-funded computer models to be able to predict the future years down the road.
"Look at me, I invented the stove!" -- Ben Franklin
I agree with your statements, and I've read similar articles in scientific periodicles. Those articles, however, are usually well hidden and no longer than half a page, because they aren't very popular. So why is rational thought about the O-zone not popular? Well it's not sensationalist, it doesn't give people something to "fight" for, and people who are "environmentally concious" just hate to admit that they are wrong.
Another thing that I don't think you touched on, our climate goes in cycles. I don't recall the exact dates, but I know that some time ago in recent history (1960's maybe?) all of the popular scientists were warning of global cooling. That's right, the earth was getting too cold and there was going to be another ice age if people didn't do something about it. Our climate is not as stable as some would imagine, and contrary to popular beleive we humans have nothing to do with it. Yes, in large cities there is smog, but that is a microclimate just around the city, and it dissipates in the atmosphere and goes away eventually, doesn't affect the global environment. The global climate is something that is very dynamic and not easily understandable. One thing is for certain though: there is no proof that we have a problem with the O-zone layer.
~ now you know