Ozone hole to disappear by 2050

[Phlegm]

From Associated Press:

(AP) The ozone hole over the Antarctic is likely to begin contracting in the future and may disappear by 2050 because of a reduction in the release of chlorofluorocarbons and other ozone-depleting gases, according to a team of Japanese scientists.

The findings are based on a series of numerical simulations carried out by Eiji Akiyoshi of the National Institute for Environmental Studies, near Tokyo, using projected emissions of chlorofluorocarbons and other gases blamed for the ozone hole.

According to a report posted Friday on the institute's Web site, the hole is at its largest now but is likely to gradually start contracting around 2020 and disappear by around 2050.

The team's findings are in line with research by other scientists.

Some, however, have suggested the hole won't heal until much later because old refrigerators and air-conditioning systems _ many in the United States and Canada _ are still releasing ozone-killing chemicals. Both countries curbed those chemicals in newer products.

Satellites and ground stations have been monitoring the ozone hole over the South Pole since its discovery in the 1980s.

Chlorofluorocarbon levels in the earth's atmosphere have been declining since the mid-1990s due to international efforts to reduce emissions.

[Minrott]

lol

From Associated Press:

(AP) Scientists pretend to have a clue about what the ozone layer does and why it does it, make statements in hopes to sway public support to fund their 40 year tuition fees.

[Narrock]

The other side to that is that the hole in the ozone comes and goes, thus being a cyclical event, and has absolutely nothing to do with fluorocarbons being emitted into the air by us evil humans.

[Arlos]

Absolutely untrue. We know exactly what causes the ozone destruction, and we even know how it does it, which is a moderately different process than what causes global warming. There is no natural process of ozone destruction to the scale that would even come close to producing a hole. None had ever existed before the introduction of Chlorinated Fluorocarbons.

Global warming is caused by various emissions containing carbon (whether in the form of particulate carbon from coal burning, CO2 from ocars, etc. etc.) that bind with the oxygen in the atmosphere (unless they already are CO2). Carbon Dioxide will pass inbound rays from the sun, but not the re-emitted infrared energy coming from the ground. Thus, since the earth cannot radiate away as much heat, it gets trapped and the earth warms up. Now, areas of ice and snow will reflect most of the energy of the Sun's rays back out, rather than absorbing it, and those reflections, since they're at a different wavelength, can pass out through the CO2. However, the warmer the earth gets, the less snow and ice there is, which means more energy gets absorbed, making it even warmer... It's an accelerating process. That's not to say there aren't natural cycles of warmer/colder, but even given that, humans are DEFINITELY impacting the speed at which it occurs, even should we not be the entire cause.

Now, as for ozone destruction. Chlorinated Fluorocarbons (aka CFCs) are pretty amazing chemicals. Lots of unique properties, and were thought to be basically inert and safe. The problem is, no one thought about what happens when those gasses rise up high enough to reach the ozone layer, where they're subject to being hit by significant levels of UV rays. What happens there is that UV ray tags the CFC, and knocks the Chlorine atom off of the CFC molecule. Chlorine is a very reactive element, and the bonds holding together O3 (ozone) are rather weak. So, Chlorine runs into an O3 and strips off one of the oxygens, resulting in ClO and O2. Now, however, it turns out that the bonds holding ClO together are MUCH weaker than the bonds that would bind 2 Oxygens together in an O2. So, should ClO run into a free O or even another ClO, the oxygens strip off the Chlorine, bond together, and the Chlorine atom is then free to break down another ozone molecule. Since Chlorine is an element, it never breaks down itself either, and whatever natural process there is to get rid of it is a slow one.

So, while both situations involve human-made gases being released into the atmosphere, the fundamental underlying processes are quite different. I have never seen, anywhere, any scientest, ever, suggest that the Ozone hole had any sort of natural origin. (maybe a CFC-producing company could trot out a paid shill to claim that, but I'd trust that as much as I did the MDs trotted out by Tobacco companies that claimed cigarettes were not a cancer risk.) Global warming is a more complex issue, and I do know there are scientists who attribute it to natural causes. Such scientists are a very small minority compared to those who believe the causes to be at least primarily man-made, but they do exist. However, I don't think nearly ANY scientist would argue that, even if the underlying cause is natural, that human beings and our waste products aren't having a significant impact on accelerating the process. Which, ultimately, may be just as bad. If life & the planetary ecology evolved based on cycles taking a certain amount of time, thus giving life a chance to adjust, if it should happen in half or 1/4 the normal time, who knows what will happen?

-Arlos

[Harrison]

None had ever existed before the introduction of Chlorinated Fluorocarbons.

And how would one figure such a magical statement to be true? I don't see any time machines...

[Arlos]

Well, golly gosh, gee whillakers. Maybe we know approximately how much ozone the atmosphere regenerates on its own. (how else would we know to estimate the hole closing by 2050, yes?) Maybe perhaps we know how long it takes ozone up at that level to naturally decay (we do). Maybe we know the various natural processes that could get substances up that high, how much does get sent up there, and what its impact would be. (part of the whole "naturally decay" bit). Maybe we know the amount of UV energy the sun gives off over its various cycles. (hint, we do again). Then maybe we know how to do some simple math to factor in the regneration, the loss rate, and the maximum loss rate, and we can figure out approximately the level of ozone up there that would be in a stable equilibrium state if not for manmade chemicals. Maybe again from those calculations we could figure out that there's no known process (nor even hint of a process) that could result in rapid enough ozone depletion of sufficient volumes to cause a hole without manmade chemicals being involved.

Gee, we could NEVER know ANY of that, huh?

Goddamn, use your head.

-Arlos

[Muglack]

You're assuming those variables have been constant over a span of billions of years. Who's to say 5 or 6 major volcanoes didn't erupt in a send loads of harmful sulfur and other chemicals into the atmosphere and completely destroy the ozone layer 2.5 billion years ago? You're arguing a "We know this hasn't happened in the RECORDED history of the world." and he's saying it might have happened before anyone was around to know it did.

[Narrock]

Scientists have already proven that volcanoes have assisted in the depletion of ozone. I just read the article about 2 weeks ago. I don't feel like googling it, but feel free if you have the energy.

[DESX]

http://en.wikipedia.org/wiki/Ozone_layer

On August 2, 2003, scientists announced that the depletion of the ozone layer may be slowing down due to the international ban on chlorofluorocarbons, chemical compounds containing chlorine, fluorine and carbon. [1] Three satellites and three ground stations confirmed that the upper atmosphere ozone depletion rate has slowed down significantly during the past decade. The study was organized by the American Geophysical Union. Some breakdown can be expected to continue due to CFCs used by nations which have not banned them, and due to gases which are already in the stratosphere. CFCs have very long atmospheric lifetimes, ranging from 50 to over 100 years, so the final recovery of the ozone layer is expected to require several lifetimes.

[Narrock]

Taken from Johnstonarchive.net:

Problems with the depletion theory. Environmentalists want CFCs banned because they say they destroy the ozone layer. However, scientifically we also see the following:

There are significant natural sources of chlorine in the atmosphere. Natural sources account for at least 20% of the chlorine in the ozone layer, and volcanic eruptions can temporarily accelerate ozone depletion.
Recorded amounts of ozone rise and fall over time, but the amount of CFCs in the atmosphere has continuously increased. On the other hand, ozone levels do correlate with solar activity (lower solar activity means less UV radiation to create ozone).
Ozone levels vary naturally by large amounts. The amount of ozone over the United States, for example, can increase and decrease by 15% or more many times during a year.
It is not clear that the amount of UV light reaching the surface of the Earth has increased.


Our understanding of chemical processes in the stratosphere have increased tremendously in the last 25 years, but many questions remain. It is clear that many predictions regarding ozone depletion have been exaggerated. On the other hand, the Antarctica ozone depletion, while only cyclical, is a significant phenomena.


With the phaseout of CFCs, alternative chemicals are being introduced for air conditioners and refrigerators. Several replacement chemicals have been developed, none of which are as efficient as freon. Many of these are toxic, flammable, or corrosive. Refrigerators and air conditioners are more expensive as a result. This will especially affect people in the third world, who need them for health reasons. Even in the United States, the phaseout of CFCs is costing everyone indirectly. Opponents of the CFC ban say that scientifically, the evidence that man is destroying the ozone layer is too weak to justify policy decisions that harm people.

This taken from Science_Outreach:

Stratospheric Ozone Depletion -
ENVIRONMENTAL CONDITION
Indicator: Stratospheric Ozone Levels




Since 1979, there has been a steady decrease in the amount of stratospheric ozone over the entire globe: a 4-6% decrease per decade in mid-latitudes, and a 10-12% decrease per decade in higher latitudes.
After the eruption of Mount Pinatubo in June 1991, there was a further decrease, and levels sank to record lows in 1992 and 1993.
The effect was particularly noticeable in the Antarctic, where the ozone hole in 1992 and 1993 was the biggest recorded, and seasonally averaged ozone over populated regions of the Northern Hemisphere were the lowest ever measured. Global ozone levels are returning to values closer to those expected from longer-term downward trend reflecting a global recovery from the effect of Pinatubo.
For the first nine months of 1994, total ozone levels over Toronto were still 3.7% flow pre-1980 levels; over Edmonton, 4.6% below; and over Resolute, 6.5% below.

Written by EPA's Stratospheric Protection Division.

This taken from:

http://volcano.und.nodak.edu/vwdocs/Gases/ozone.html

Volcanoes and Ozone
Ozone is a gas made of three oxygen atoms. Ozone is bluish in color and harmful to breathe. Most of the Earth's ozone (about 90%) is in the stratosphere. The stratosphere is a layer in the atmosphere from about 10km to about 50km in altitude. Ozone is important because it absorbs specific wavelengths of ultraviolet radiation that are particularly harmful to living organisms. The ozone layer prevents most of this harmful radiation from reaching the ground.

As concern grew over depletion of ozone in the stratosphere scientists examined the role of volcanoes. They noted that the gases emitted by most eruptions never leave the troposphere, the layer in the atmosphere from the surface to about 10km.

Hydrogen chloride released by volcanoes can cause drastic reductions in ozone if concentrations reach high levels (about 15-20 ppb by volume)(Prather and others, 1984). As the El Chichon eruption cloud was spreading, the amount of HCl in the cloud increased by 40% (Mankin and Coffey, 1984). This increase represents about 10% of the global inventory of HCl in the stratosphere. Other large eruptions (Tambora, Krakatau, and Agung) may have released almost ten-times more HCl into the stratosphere than the amount of chlorine commonly present in the stratosphere (Pinto and others, 1989). At least two factors reduce the impact of HCl, chlorine appears to be preferentially released during low-levels of volcanic activity and thus may be limited to the troposphere, where it can be scrubbed by rain. Hydrogen chloride may also condense in the rising volcanic plume, again to be scrubbed out by rain or ice. Lack of HCl in ice cores with high amounts of H2SO4 (from large eruptions) may indicate ambient stratospheric conditions are extremely efficient at removing HCl. Thus, most HCl never has the opportunity to react with ozone. No increase in stratospheric chlorine was observed during the 1991 eruption of Mt. Pinatubo.

Volcanoes account for about 3% of chlorine in the stratosphere. Methyl chloride produces about 15% of the chlorine entering the stratosphere. The remaining 82% of stratospheric chlorine comes from man-made sources, mostly in the form of chlorofluorocarbons.

Although volcanic gases do not play a direct role in destroying ozone they may play a harmful indirect role. Scientists have found that particles, or aerosols, produced by major volcanic eruptions accelerate ozone destruction. The particles themselves do not directly destroy ozone but they do provide a surface upon which chemical reactions can take place. This enhances chlorine-driven ozone depletion. Fortunately, the effects from volcanoes are short lived and after two or three years, the volcanic particles settle out of the atmosphere.

Study of ozone amounts before and after the 1991 eruption of Mt. Pinatubo show that there were significant decreases in lower stratospheric ozone (Grant and others, 1994). The amount of ozone in the 16-28 km region was some reduced by 33% compared to pre-eruption amounts. A similar reduced amount of ozone was measured in the summer of 1992.

So, we learned that ozone depletion is A. Cyclical B. Caused by volcanic activity and C. By CFC's emitted from refrigeration.

[Lionking]

Give me my FREON back, Faggot liberals!