Ozone Layer on the rebound?

[Brian Ellis]

That would make somewhat more sense than publishing DUs, but there is a difference according to wavelengths. Most UV light (>98%) is UVA (long wavelength) which hardly penetrates the skin but can cause severe redness and itching. UVB (medium wavelength) is what the ozone layer attenuates (at least some important wavelengths) and, by itself, can cause pyrimidine dimers which can affect DNA, causing squamous cell and basal cell cancers and, worse, melanomas, possibly years or decades after over-exposure, without a great deal of reddening of the skin at the time of exposure. Fortunately, UVB without UVA is rare so, if UVB is not excessively high, sunburn occurs with just a limited risk of cancer. Unfortunately, when the O3 layer passes more UVB, this natural "safety factor" is reduced.

Besides sunburn/cancer, excess UVB may also cause other effects, such as reduced immune responses, cataracts etc. (Sheep grazing in S. Argentina have been blinded because of UV levels). Other than animal responses, leguminous plants have a reduced yield, especially soya, and the krill forming the base of the food chain in the Antarctic and W Coast of S America are also suffering.

Protection from the sun is wise but some sun creams are effective with only UVA; purchase only those with both UVA and UVB protection and USE them if there is any risk and wear a broad-brimmed hat if the UVB levels are high (your local met station should be able to advise).

It is estimated that about 30,000-40,000 persons/year in the USA alone are treated for excess UVB exposure-related problems, over and above the pre-CFC baseline, and this figure is increasing by 10-12%/year.

[Nowhere]

BTW, this all reminded me of one argument of someone once heared...

So the question: when were the highest (globally) emmisions of OD gases/to which years we can "thank" most for the mess?

[Brian Ellis]

This curve will partially answer your question, but it applies only the CFCs and HCFCs, not to, 1,1,1-trichloroethane, halons or other OD substances.

There is still substantial production of many of these substances in developing countries, with phase-out scheduled for 2010.

There are two substances with widespread usage in developed countries:
- methyl bromide, used as a soil sterilant and crop pesticide. This should be phased out this year in developed countries, but the biggest user (USA) has obtained a stay of execution on the grounds that there is no substitute for tomatoes and strawberries, despite the fact that most other countries have found and employ substitutes satisfactorily and economically. This appears to be a political decision, fired by farmers' lobbies. It has caused bitter wrangling.

- n-propyl bromide, with widespread use as an industrial solvent. For an obscure technical reason, it has escaped introduction into the Montreal Protocol. The two major producers and users (China and USA) have exploited this loophole, even though there is substantial evidence that it is a neurotoxin (like a mild nerve gas). The EU has banned its use.

Hope this helps.

The second curve shows the estimated cancer rates due to ozone depletion with different scenarios, the lowest ones being the result of the Protocol and its amendments. The peak corresponds roughly with the peak of O3 depletion, with possibly only a few years delay. The reason is that, as the rate increases, so public awareness will increase and people will use more protection. By 2040, it is expected that most of the white population (most prone) will never stick their noses outside with any unprotected skin!

[Nowhere]

Thanks Brian, that graph is all I need
(completelly unscientific argument with father:
I: In enormous part what was beeing done in your times is responsible for current situation.
he: blah, but then everything was OK, it is now that there are problems
I: Uhmm...ok, those are the results of actions from then.
he: Impossible, everything was OK after all!)

Seriously...it saddens me a little when I see than some governments ignore all this...
And it's probably because of those sunburns of mine...previosuly I've had the impression that...yeah, perhaps not everybody are doing what they should, but it's generally OK. Well...it isn't.
Apparently only public outcry would silence some lobbys...how probable it is that some natural phenomena will create over some parts of N America something that we had last Spring? (Chinese government wouldn't care unfortunatelly...)

BTW, what natural phenomenas are possible that would make our situation better or...worse? In the long run of course.

[Brian Ellis]

Actually, most governments ARE adhering to the Protocol to a reasonably close tolerance. About 190 countries have signed and ratified it and it has been a remarkable success. Taiwan has not signed for obvious reasons, but they follow the prescriptions because, if they didn't, they would not be able to export anything made with the help of OD substances.

I've travelled widely to monitor and help countries implement the provisions. Yes, there are errors. For example, a drum of 1,1,1-trichloroethane or even carbon tetrachloride (OD substances) is almost indistinguishable from one of non-OD 1,1,2-trichloroethylene (short of sophisticated gas chromatography analyses), other than the label, so fraud would be easy, along with illegal imports. But relatively little has been done, other than some mis-reporting, mainly because governments don't have a clue on technicalities. As far as illegal imports are concerned, the worst cases have been in the USA, where mobile aircon gases have been illegally imported from Mexico. Some of the importers have received 15/20 years with fines of up to $1M for their pains: worse punishment than for rape or murder, in some cases! Tough, but it has been effective in stopping it, on the whole.

I don't think any natural phenomenon would persude many people to change their minds. After all, Katrina is probably a result of climate change, certainly as far as its intensity was concerned. But will it have any effect on the Administration's thinking?

[Brian Ellis]

May 21, 2004: CFC Smuggler Sentenced to Serve 17 Years in Prison
Marc M. Harris was sentenced in U.S. District Court to 204 months imprisonment, to be followed by 3 years supervised release, and a $20,324,560 fine. Mr. Harris was also ordered to pay restitution to the Internal Revenue Service in the amount of $6,588,949.50 for evasion of federal excise taxes on the sale of ozone-depleting refrigerants to customers in South Florida.

Howzat for a tough sentence?