Environmentalists piss me off...

[Gurm]

In the words of Eric Cartman.

I swear, if I hear one more idiot on the news spew complete rubbish about how CFC's (which are HEAVIER than air last time I checked) manage to FLOAT all the way to ANTARCTICA in order to increase the size of a hole that has been fluctuating in size for... oh... the entire history of the planet... I'm gonna snap.

Let's start from the beginning:

1. CFC's do NOT cause ozone depletion.
2. Natural events cause ozone depletion.
3. The replacement for CFC's costs more, but is cheaper to make.
4. Someone is profiting on the supposed ozone hole panic. Whoa! Big surprise!

Seriously though. The air force first noticed the ozone hole the very first time they flew in that direction. Almost a hundred years ago. They just never mentioned it to the environmental nuts until a few years back. BIG MISTAKE.

- Gurm

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Listen up, you primitive screwheads! See this? This is my BOOMSTICK! Etc. etc.

[Greebe]

Gurm, I'd suggest you talk to some PH.D chemistist on that one. CFC's do indeed breakdown ozone. The base chemical structure is heavier than air but takes very little time to breakdown into simplier molecules which are lighter.

But you are right, this is a naturally occuring phenomenon. It's not CFC's alone that are doing the damage. Look what Mount Pinatubo did just a few years back.

side note: ozone may be what protects us from harmful solar radiation, but it is also deadly to ALL lifeforms. Hence "NOZONE" days, when an atmospheric inversion layer will prevent it from rising out of harms way.

[SteveC]

Here's a fun test -

Take 1 laser printer.
Open it up.
Remove Ozone filter.
Continuously print lots of stuff.
Breathe in the air the printer kicks out.
Hmmm.... you'll feel wonderful!

PS: Don't try this at home, kids!

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Cheers,
Steve

"Life is what we make of it, yet most of us just fake"

[Brian R.]

Well Gurm - I think you are listening to the wrong people when it comes to atmospheric chemistry. Let me give you a few facts concerning this issue:

"1. CFC's do NOT cause ozone depletion."

Ozone is a very reactive form of oxygen which can be depleted by any number of processes. CFCs have been shown to degrade to substances in the upper atmosphere which do react with ozone. These substances have been proven to come from CFCs, their concentration in the upper atmosphere have been measured and there reactivity toward ozone have been proven and the rate of reaction determined. There is no doubt in the peer-reviewed scientific literature that this process is real and contributes measurably to ozone depletion.

"2. Natural events cause ozone depletion."

True - Many substances will react with ozone at some rate.

"3. The replacement for CFC's costs more, but is cheaper to make."

Unknown

"4. Someone is profiting on the supposed ozone hole panic"

No doubt. There will always be a profit in something used by the pound in most every car. Not a panic, an attempt to minimize ozone depletion.

Your reasoning is faulty when you discussed your scepticism of CFCs going to Antarctica. CFCs are indeed heavier than air. That only means they have a slower molecular speed at any given temperature. If you take a flask filled with CFC-12, for example, and pour it into a flask filled with air, the CFC will displace the air and fall into the bottom of the air-containing flask.

However, if you take a fan and mix the two thouroghly, they will never separate with the CFC on the bottom and the air on the top. This is the property of a solution.

This property can be seen in mixtures of gases which are commercially available. The individual components of these mixtures have differing densities, yet they never require mixing. Once they are well mixed, their concentration in every part of the gas cylinder remains constant.

As a result of this, CFCs distribute throughout the atmosphere (albeit in varying concentrations) and eventually reach every portion of the atmosphere, including that over Antarctica.

The concentrations of CFC degradants (reactive species) and ozone in the atmosphere, anywhere, can be directly measured. Since the rate of reaction of the CFC degradants with ozone is known, the rate of depletion due to CFC contamination is known (can be calculated).

I've tried to supply only facts. I work with this issue indirectly and am concerned about the validity of this problem, as you are.

PS I am a PhD chemist and in no way shape or form am I an environmentalist.

[This message has been edited by Brian R. (edited 06 October 2000).]

[Gurm]

Grr. Look, the point is that hair spray canisters didn't "create" or noticeably "enlarge" the "hole" in the ozone layer. It's been there for billions of years, and will be there long after the human species has died off.

It's the height of human pride and arrogance to think that WE are the reason for everything.

If we were in the middle of an ice age, instead of in the middle of a warming trend, the environmentalists would blame global cooling on CFC's and cars as well.

- Gurm

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Listen up, you primitive screwheads! See this? This is my BOOMSTICK! Etc. etc.

[Brian R.]

One of the reasons ozone has been disappearing at the rate it has is our production and subsequent release into the atmosphere of billions of pounds of CFCs. No doubt about it. Its use in every car manufactured after about 1970 (?) and before 1993, and in every commercial and home air conditioner, and every refridgerator and freezer is the problem, not hair spray canisters. Don't trivialize thie problem, talk facts, please. This is a serious problem and not one deserving additional uninformed opinions.

[Greebe]

What has me is that they pulled most of the old CFC's off the market (hairspray's etc) and then pulled another boner by using CO2!

Yeah that's the ticket, Global warming at it's best!

FYI R12, 134a etc is damaging, but one they don't mention is Halon. This cfc, while only released to extingush fire is 10 times more ozone depleting. Also the worst side effect is that once superheated, which causes a breakdown in it's structure, results in the formation of another ultra harmful gas called phosgene, ie Mustard gas! (other cfc's do this also, just not to the same extreme).

1 whif and I'll personally tell you it'll take your breath away (burn the heck out of you eyes, skin, especially mucus membranes and the lungs)

[Greebe]

Brian, most frig's and freezers use ammonia not cfc's.

[Greebe]

Forgot another... altho old style cfc's are not used in the modernized nations, just like DDT has been banned, most third world nations still use it! While the US is a major target for the enviromentalists, look how most manufacturing is leaving the US and going to these unregulated nations. It's not just about cheap labor. Another big plus factor of NAFTA! (*&#%^@&$@#!!!)

[Brian R.]

Greebe, I think you are missinformed about the refrigerant in those appliances.

Edit - I'll agree that ammonia is used as a refrigerant. It's my estimate that its use is small compared with CFCs, however.

If I'm not mistaken, it is used in large-scale refrigeration units for outdoor use only.

[This message has been edited by Brian R. (edited 06 October 2000).]

[Greebe]

I may just possibly be... my father was my source of information and well, he's now in a better place.

[Rags]

CFC's in their original forms, and second and third stage forms can break down ozone. The problem I have with that claim, and I agree with Gurm on this one, is that CFC's cannot make their way into the ozone layer. Let's take R12 for example. R12 is one of the most resiliant compounds made. It doesn't like to combine with anything, and it does NOT like to break down. Direct sunlight will make it degrade to a point, but the leftover chemicals are both heavier than air. In order for anything to make it into the ozone layer from down here (without man taking it up there to begin with), the chemical has to be less dense than 03. And CFC's just don't do it. Now, there may be some way that airplanes, shuttles, and volcanic eruptions may take some of that stuff up there, but don't count on man making that big of a dent

Rags

[blackmouser]

small comment on the refrigeration thing....I've worked in kitchens for ten years and I do believe most cooling systems for regular commercial use are still done with freon. at least it was last year...and i think the whole key to the ozone issue is that it is just a layer of oxygen in single atom form which makes it more bondable to other, more complex molecular structures...and since humans are the only group producing these complex structures, this would definitely account for some depletion of this layer aside from the more normal forms of wear...

[Gurm]

Rags hit the nail on the head.

I don't contest that CFC's break down ozone. I've seen the experiments, and their results.

HOWEVER, I _do_ contest the idea that any CFC's make their way to the STRATOSPHERE. It's just not bloody likely.

Now, some thoughts:

1. Who made virtually all R12? Dupont. Who had an aging factory that needed to be dismantled? Dupont. Who was one of the biggest supporters of the "R12 causes ozone depletion" propaganda? Dupont. Who got a government contract to build a factory to produce R134? Dupont. Hmm...

2. When did CFC's come into common use? I'm betting not until the middle of this century. How long has the ozone hole been there (and how long has it been THIS BIG)? We detected it the early part of this century. Early air force flights over that part of the world detected the ozone hole. So... how did it get there (and get that big) if CFC's are the cause, when CFC's didn't come along until years later?

Nota Bene: Don't go challenging me on this piece of trivia. I have it on highest authority from the aeronautics folks at one of the country's top labs.

3. I have yet to hear a plausible explanation for how CFC's get up to the ozone layer. CFC's are heavier than air. The compounds into which they degrade are heavier than air. I've heard wild theories concerning brownian motion. These theories in turn fail to explain how these ozone-depleting chemicals manage to make their way to the south pole exclusively, when most of them are produced in the northern hemisphere. Even if they DID have a tendency to drift via brownian motion they would drift with wind currents and they would drift NORTH.

4. I've talked to people in Texas recently who are having bad air days. On these days, their ozone concentration is dangerously HIGH. If CFC's were causing ozone depletion, wouldn't ozone levels all over the globe be going DOWN? They aren't.

So, let's review some facts:

1. CFC's break down ozone. True.

2. CFC's are heavier than air. True.

3. Global ozone levels have remained constant over the past 100 years. True.

4. Global ozone levels have likely remained relatively constant over the past billion years... TRUE.

5. Nothing mankind has done in the past 50 years has made a significant impact on the ozone layer. I posit... TRUE.

- Gurm

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Listen up, you primitive screwheads! See this? This is my BOOMSTICK! Etc. etc.

[Brian R.]

Rags - The wind will eventually cause all gases to be distributed around the globe at all altitudes. Gas mixing is driven by entropy. The more dilute and uniform a solution, the lower its Gibbs free energy. This is a thermodynamic effect which is irreversible without a large expenditure of energy. Density has nothing to do with it.

Also, no matter what the rate of R-12 decomposition, eventually all R-12 will be converted to degradants and react with ozone. The reaction between ozone and the decomposition product is very fast. Once the degradant is formed, it consumes ozone.

As I said above, these chemical reactions are well characterized and their rates of reactions under the conditions present in the upper atmopheric, and the concentrations of both ozone and cfc degradants are well known. There is no additional information needed to know the rate of ozone loss due to this process.

Sorry - Your chemical intuition is failing you.