Personally, it is more like an "ozone donut", but for political reasons, people forget about the high concentration of ozone around the hole.
Posted on 09/17/2002 10:29:45 AM PDT by wallcrawlr
SYDNEY (Reuters) - The hole in the ozone layer over Antarctica may close within 50 years as the level of destructive ozone-depleting CFCs in the atmosphere is now declining, one of the world's leading atmospheric scientists said Tuesday.
Paul Fraser with the Australian government's Commonwealth Scientific and Industrial Research Organization (CSIRO) said he had measured a decline in ozone-destroying gases since 2000.
"The major culprit in the production of the ozone hole is CFCs and they have started to decline in the lower atmosphere," Fraser told Reuters in an interview.
"We think the ozone hole will recover by about 2050," said Fraser, from CSIRO's atmospheric division and a lead author on a U.N. report on the ozone layer released Monday.
The report said ozone-depleting gases in the upper atmosphere had been at or near their peak in 2000, but the world was making steady progress toward the recovery of the ozone layer.
It said scientific data showed levels of ozone-depleting gases in the lower atmosphere were "declining, albeit slowly," but the ozone would be vulnerable for a decade.
The ozone layer is essential for life on earth, shielding the earth from the harmful ultraviolet-B radiation from the sun and completely screening out lethal UV-C radiation.
Chlorine from chlorofluorocarbons (CFCs) is responsible for destroying part of the ozone layer over Antarctica. CFCs have been widely used since the 1930s in refrigerators, and air conditioners and remain in the atmosphere for decades.
Under the 1987 Montreal Protocol, developing countries committed themselves to halving consumption and production of CFCs by 2005 and to achieving an 85 percent cut by 2007.
Fraser, who monitors CFCs from Australia's southern island of Tasmania, said that in 1950 the atmospheric level of chlorine from CFCs had been zero, rose to a peak of 2.15 parts per million in 2000, but had fallen one percent a year since 2000.
"We are now at a point where the atmosphere can actually remove CFCs faster than they are being released into the atmosphere," said Fraser, adding the actual decline in CFCs had not been measured when the U.N. report was compiled in 2000.
The U.N. report, the latest in a series of four-yearly reports reviewing the ozone layer since the Montreal Protocol, said the reduction in CFCs proved the protocol was working.
But the report warned that the hole over Antarctica would only close fully if countries continued to adhere to the protocol and if there were no other factors adversely affecting the ozone layer like a major increase in greenhouse gases.
"These results confirm that the Montreal Protocol is achieving its objectives. During the next decades we should see a recovery of the ozone layer," said the report.
Does this surprise anyone?
I'll bet this question wasnt even asked by a reporter back then.
The most common CFC refrigerant, R-12, is over five times heavier than air -- it drops like a rock and flows downhill as water does. A fact that environmental "scientists" don't seem to know.
When "respected" scientists support fraud, their homeland culture's corruption factor has arrived at the pure-evil level.
Gases come in a variety of densities. While heavy gases may temporarily pool in an enclosed space, given time they will dissipate and mix with the atmosphere. If they didn't the different gases that make up air would all be stratified and there would be no measurable CFCs more than an inch off the ground.
Personally, it is more like an "ozone donut", but for political reasons, people forget about the high concentration of ozone around the hole.
Inert gases are those that don't react with any other substance, so diffusion at the molecular level would almost solely depend on the stability of the molecule; and CFC refrigerants are known to function well (without molecular disassociation occurring) inside refrigeration systems for 20 - 30 years.
When CFCs are released into the atmosphere, it is the CFC molecule that will mix with air, with little if any disassociation occurring. And the molecular weight difference between air and those highly stable and inert R-12 molecules will still outweigh air at the 5.7 to 1 ratio.
If the R-12 goes anywhere once it's in a mine shaft, it will go into cracks and crevices until it reaches water or bedrock.
There's a question ... Will water absorb an inert gas?
You are confusing diffusion with dissociation. Diffusion is a mixing of molecular gases, and dissociation is the breakdown of gaseous molecules into those chemicals within the gas.
Chemists tell us it is chlorine that breaks up ozone, and atmospheric scientists are saying that chlorine is coming from CFCs. Meanwhile, volcanoes spit out far more dirty, but chemical active, chlorine into upper atmospheric regions than dissociation could ever provide.
Required from scientists is proof that heavy and inert CFC molecules can and do dissociate into chlorine atoms which can move to the upper atmosphere to the degree required to outpace volcanic chlorine production.
Until then, I hold that modern environmental science is built on fraud.
So the question returns to ... How does an intact, heavy, stable, almost completly inert, gas molecule get into the presence of O3 in the upper atmosphere?
Need I picture a bowling ball somehow making its way to 80,000 feet thanks to a tornado?
There's your physics question of the day.
Ask yourself this question-
How does a light, inert gas such as helium ever get down to ground level?
By your rationale, it should all be somewhere at the top of the atmosphere. Carbon dioxide also weighs more than air and is quite stable (average lifetime around 200 years). Yet it easily diffuses through the atmosphere. If the atmosphere stratified by molecular weight, we'd all die.
How does the composition of the atmosphere change with altitude? (Or, how can CFC's get up to the stratosphere when they are heavier than air?)In the earth's troposphere and stratosphere, most _stable_ chemical species are "well-mixed" - their mixing ratios are independent of altitude. If a species' mixing ratio changes with altitude, some kind of physical or chemical transformation is taking place. That last statement may seem surprising - one might expect the heavier molecules to dominate at lower altitudes. The mixing ratio of Krypton (mass 84), then, would decrease with altitude, while that of Helium (mass 4) would increase. In reality, however, molecules do not segregate by weight in the troposphere or stratosphere. The relative proportions of Helium, Nitrogen, and Krypton are unchanged up to about 100 km.
Why is this? Vertical transport in the troposphere takes place by convection and turbulent mixing. In the stratosphere and in the mesosphere, it takes place by "eddy diffusion" - the gradual mechanical mixing of gas by motions on small scales. These mechanisms do not distinguish molecular masses. Only at much higher altitudes do mean free paths become so large that _molecular_ diffusion dominates and gravity is able to separate the different species, bringing hydrogen and helium atoms to the top. The lower and middle atmosphere are thus said to be "well mixed." [Chamberlain and Hunten] [Wayne] [Wallace and Hobbs]
Experimental measurements of the fluorocarbon CF4 demonstrate this homogeneous mixing. CF4 has an extremely long lifetime in the stratosphere - probably many thousands of years. The mixing ratio of CF4 in the stratosphere was found to be 0.056-0.060 ppbv from 10-50 km, with no overall trend. [Zander et al. 1992]
An important trace gas that is *not* well-mixed is water vapor. The lower troposphere contains a great deal of water - as much as 30,000 ppmv in humid tropical latitudes. High in the troposphere, however, the water condenses and falls to the earth as rain or snow, so that the stratosphere is extremely dry, typical mixing ratios being about 5 ppmv. Indeed, the transport of water vapor from troposphere to stratosphere is even less efficient than this would suggest, since much of the small amount of water in the stratosphere is actually produced _in situ_ by the oxidation of stratospheric methane. [SAGE II]
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