SF Gate

Chlorine levels in the atmosphere falling, ozone layer repairing itself, scientists say

Chlorine-based chemical levels in the atmosphere are falling, and the hole in the ozone layer over Antarctica should close within 50 years, according to an Australian government-funded study.

Although the ozone layer had not yet begun to repair itself, the hole would probably start closing within five years, and should fully recover by 2050, said Paul Fraser, of the Australian government-funded Commonwealth Scientific and Industrial Research Organization, or CSIRO.

Fraser said ozone layer recovery would be a result of international efforts to ban ozone-depleting chlorofluorocarbons in the mid-1990s.

CSIRO atmospheric monitoring has found that chlorine from chlorofluorocarbons, or CFCs, leveled off in the troposphere -- the lower atmosphere -- two years ago, and is falling for the first time in more than 20 years.

The ozone layer over the southern continent of Antarctica has suffered the most damage from CFCs, which have eaten a hole about 10 million square miles. The hole is about three times the size of Australia.

The CSIRO and Australia's Bureau of Meteorology have been monitoring and recording the level of chlorine in the troposphere over Australia's southern island state of Tasmania for several years.

Scientists expect the chlorine decrease will lead to a gradual recovery of the ozone layer during the next half century. In turn, the ozone recovery will decrease the risk of skin cancer and similar ailments in the far southern hemisphere, where damage to the protective layer of gas is most serious.

New Zealand ozone researcher Greg Bodecker, when asked about the Australian findings Wednesday, said measurements from a number of sites around the world, by several research groups, "have confirmed that stratospheric chlorine levels have indeed peaked."

Measurements at one site in New Zealand have confirmed that stratospheric chlorine levels "are probably now decreasing," Bodecker said.

CFCs were banned in the developed world in the mid-1990s after a pact signed at a 1989 international conference in Montreal, Canada. They are still being phased out in developing countries.

The prohibition of CFCs -- which were used in refrigerators, air conditioners and aerosol spray cans -- came after it was found they were breaking up the earth's ozone, a thin layer of atmosphere that filters the sun's damaging ultraviolet rays and protects humans from skin cancer.

"Once CFCs have been phased out of the developing world ... by about 2005, the most persistent ozone-depleting chemicals in the atmosphere will no longer be released in any significant amounts," Fraser told The Associated Press in a telephone interview on Tuesday.

"That means that the atmosphere can work its magic and start to destroy these chemicals at a rate faster than they're being released," he added.

Fraser said the discovery proved that direct action taken by the international community on environmental issues could make a difference.

On Monday, the U.N. Environmental Program and World Meteorological Organization said the ozone layer remains at risk despite signs of recovery.

Also Monday, scientists meeting in Utah said it would take 50 years for the hole in the ozone layer to disappear.

The "world is making steady progress toward the recovery of the ozone layer ... with the total amount of ozone-depleting chemicals in the lower atmosphere continuing to decline, albeit slowly," the organizations said in a statement.

There really isn't anything we can do to repair it ourselves, just prevent further damage. I think.

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Originally posted by bauhaus:

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Originally posted by reactionary05:

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Originally posted by bauhaus:
reactionary do you take care of your car? change the oil, make sure all the fluids are clean? wash/wax it? What happens when you don't do these things?

If I fail to change the oil, will it repair itself in 50 years?

it wouldnt last more than 3 years.

Congratulations, you two just proved one very important fact: The global environment is not an automobile.

It's a false analogy, just drop it.

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Haha. If people like you were in charge, we'd be like North Korea: "Corporation free, since '53!"

Meaning?

Reactionary, simply because I care a little bit about where I live doesn't mean I'm anti-business. Why do you always assume (wrongly) about me? First I'm a liberal, then a communist, now anti-business? Jeez, man, don't quit your day job.

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Originally posted by reactionary05:

quote:

Originally posted by bauhaus:
reactionary do you take care of your car? change the oil, make sure all the fluids are clean? wash/wax it? What happens when you don't do these things?

If I fail to change the oil, will it repair itself in 50 years?

it wouldnt last more than 3 years.

quote:

Originally posted by bauhaus:
reactionary do you take care of your car? change the oil, make sure all the fluids are clean? wash/wax it? What happens when you don't do these things?

If I fail to change the oil, will it repair itself in 50 years?

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Originally posted by clpo13:
Reactionary, as long as there are people like you on the earth (by that I mean seriously uncaring about the well-being of the environment), the earth will always be at risk.

Haha. If people like you were in charge, we'd be like North Korea: "Corporation free, since '53!"

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Originally posted by bauhaus:
reactionary do you take care of your car? change the oil, make sure all the fluids are clean? wash/wax it? What happens when you don't do these things?

Sell it and buy a new one!

reactionary do you take care of your car? change the oil, make sure all the fluids are clean? wash/wax it? What happens when you don't do these things?

If you just sit back and watch, nothing will ever come about from it. You have to get in their and do something, however small, to help the environment, whether it be picking up litter, checking cans before you buy to make sure they say "No CFCs," or taking the extra walk to the back of the cafeteria to put your plastics or metals in the recycle bin. Everyone just needs to realise that this is everyone's earth. Not just the ones who are concerned about its well-being.

-----"""Reactionary, as long as there are people like you on the earth (by that I mean seriously uncaring about the well-being of the environment), the earth will always be at risk."""---

I'm gonna go with clpo on this one.

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I did a homestay in Australia, and our host family, like most Australians, recycle, reuse their own bags when shopping, conserve water (they have a 1/2 flush option on their toilets), and they try to save electricity. If America could do that we'd really be on our way, huh?

Half my community lives like this, and I do my best as well. Also from my experiance in England, that half flush feature appears to be equivilant to a full flush in a newer water conserving toilet here in the US. The full flush was just insanely unnessesary.

Reactionary, as long as there are people like you on the earth (by that I mean seriously uncaring about the well-being of the environment), the earth will always be at risk.

This study was done in Australia? You know we could really learn from them. They take the small steps to help the environment in their daily lives. I did a homestay in Australia, and our host family, like most Australians, recycle, reuse their own bags when shopping, conserve water (they have a 1/2 flush option on their toilets), and they try to save electricity. If America could do that we'd really be on our way, huh?

We ignore so many of the small things that could help our environment out. Some of the newer car models are helping, too. But individuals are now driving cars that run on all kinds of wierd things (moonshine, for example). Why aren't these ideas hitting the market? Why not more public transportation? It's all so easy, and we wouldn't have to worry about the holes in the o-zone layer.

Is 50 years of fixing the problem really going to counter another 50 of our pollution? Guess we'll see!

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Originally posted by YNmod1:
Um, it took what 100 years to make those holes? Thats a very short time.

Its like a virus. When its first introduced in a person, it can do lots of damage in not alot of time. now that the virus is removed, and the earth will no longer be a risk.

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Originally posted by reactionary05:

Simply more proof that environment is not fragile.

Um, it took what 100 years to make those holes? Thats a very short time.

The reduction of CFCs is a great sucess of good science and environmental policy. Anyone who says that it's an example of why we shouldn't worry about the environment is misguided. It's an example of why we SHOULD pay attention and find out the real answers to get the real solutions.

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Simply more proof that environment is not fragile.

No, it's proof that the envirnoment can fix itself. That there are holes at all show that the environment isn't invulnerable.

the fact that holes so large could have come about shows the environment is fragile, mans presence is easy to see all over the globe, but it is more resiliant than we think, and our contribtion to the problems is questionable.

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Originally posted by clpo13:
Well, duh. Take away the stuff that eats away at the ozone, and the ozone will come back. That's common sense.

Besides, no one's worrying about the ozone layer any more. That's so...'90s.

Simply more proof that environment is not fragile.