Scientists: Ozone hole size sets record

Thu Oct 19, 8:19 PM ET

WASHINGTON - This year's Antarctic ozone hole is the biggest ever, government scientists said Thursday. The so-called hole is a region where there is severe depletion of the layer of ozone — a form of oxygen — in the upper atmosphere that protects life on Earth by blocking the sun's ultraviolet rays.
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Scientists say human-produced gases such as bromine and chlorine damage the layer, causing the hole. That's why many compounds such as spray-can propellants have been banned in recent years.

"From Sept. 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles," said Paul Newman, atmospheric scientist at
NASA's Goddard Space Flight Center, Greenbelt, Md. That's larger than the area of North America.

In addition, satellite measurements observed a low reading of 85 Dobson units of ozone on Oct. 8. That's down from a thickness of 300 Dobson units in July.

The ozone hole is considered to be the area with total column ozone below 220 Dobson Units. A reading of 100 Dobson Units means that if all the ozone in the air above a point were brought down to sea-level pressure and cooled to freezing it would form a layer 1 centimeter thick. A reading of 250 Dobson Units translates to a layer about an inch thick.

In a critical layer of air between eight and 13 miles above the surface, the measurement was only 1.2 Dobson unit, down from 125 in July.

"These numbers mean the ozone is virtually gone in this layer of the atmosphere," said David Hofmann, director of the Global Monitoring Division at the National Oceanic and Atmospheric Administration's Earth System Research Laboratory. "The depleted layer has an unusual vertical extent this year, so it appears that the 2006 ozone hole will go down as a record-setter."

The size and thickness of the ozone hole varies from year to year, becoming larger when temperatures are lower.

Because of international agreements banning ozone-depleting substances, researchers calculated that these chemicals peaked in Antarctica in 2001 and have been declining. However, many of them have extremely long lifetimes once released into the air.

While there are year-to-year variations, scientists expect a slow recovery of the ozone layer by the year 2065, anticipating declines in the use of damaging chemicals.

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On the Net:

NASA's ozone research: http://www.nasa.gov/vision/earth/lookingatearth/ozone_record.html

Wouldn't that make a great film: giant mutant penguins caused by the ozone hole. Wow. I'd pay $1000 to see that.

the world is fucked. al gore is wrong, we're past saving.

the ice caps are melting, much discussed, but whats not discussed often is that they (did) reflect a certain % of light/heat back into space. as they melt, this number decreases (permanently) and the earth gets that much hotter... a bigger deal than it sounds.

also bad is the thawing of the tundra and the warming of waters... both of which will do far greater damage than the industrial revolution did.

stephen hawkins, aka the smartest man in the world, said we might not even have a hundred years left. wowzers.

Buy land in the Rockies and sunblock.

Problem solved.

stephen hawkins, aka the smartest man in the world, said we might not even have a hundred years left. wowzers.
That's Stephen Hawking, and his "how can we survive the next hundred years" question isn't just about global warming, not by any means. Not that I would presume to speak for him (he has a cooler voice), but Hawking asked that as a challenge to you, to me, to the world. His take is: We have the capability to screw up the world dramatically in ways our forebears never did. We've done things with unintended massively bad consequences already, only some of which we fully realize. We really should get our act together to save our world. We should look at space exploration in case we've screwed it up beyond immediate repair already and we just don't know it yet.

i always think about that when i see a truck or an old car spewing black smoke from it's tailpipe. time to stock up on SPF-1000 lotion.....

well theres some of the bs. Electric and hybrid cars should have become standard by now IMO. but we're addicted to oil. oh wait the oil companies are.:wtf:

well theres some of the bs. Electric and hybrid cars should have become standard by now IMO. but we're addicted to oil. oh wait the oil companies are.:wtf:

I'm not addicted to oil, I'm addicted to convenience and money. Right now if I sacrificed maybe 20% in convenience, comfort, cost, choice, etc... I could probably save 80% in my personal energy consumption... but seriously, that's not going to happen.

Here's George Bush's recent statement about global warming.
tnXCJySzIuw

And on a more serious note, one of the prinicple ozone researchers (he got a Nobel for figuring it out) has been proposing something radical:

http://www.alertnet.org/thenews/newsdesk/L14558285.htm

By Ari Rabinovitch

TEL AVIV, Dec 15 (Reuters) - Nobel Prize laureate Paul Crutzen says he has new data supporting his controversial theory that injecting the common pollutant sulphur into the atmosphere would cancel out the greenhouse effect.

Though such a project could not be implemented for at least 10 years, the data is aimed at appeasing critics of the idea he first championed in the scientific journal Climatic Change in August.

The Dutch meteorologist showed what he calls the positive cooling effect of adding a layer of sulphates to the atmosphere at a global warming conference at the Porter School for Environmental Studies in Tel Aviv.

He said new, detailed calculations carried out since August showed the project would indeed lower global temperatures.

"Our calculations using the best models available have shown that injecting 1 million tonnes of sulphur a year would cool down the climate so the greenhouse effect is wiped out," Crutzen told Reuters.

An added layer of sulphates in the stratosphere, some 10 miles (16 km) above the earth, would reflect sunlight into space and reduce solar radiation reaching the earth's surface, Crutzen said.

He said he envisioned giant cannons or balloons dispersing the sulphur to offset the build-up of greenhouse gases such as carbon dioxide, largely released by burning fossil fuels in power plants, factories and vehicles.

The world has struggled for decades to reduce sulphur pollution, a component of acid rain that kills forests and fish, mainly through tighter controls on burning coal.

"We are now entering a very intensive period of model calculations and following that we will conduct small experiments to test the sulphur oxidation mechanisms that we calculated," Crutzen said.

NO LONGER TABOO

Crutzen said he planned to publish the new findings in a few months' time in one of the major scientific journals.

The idea of using sulphur to combat global warming -- which most scientists say will bring more floods, desertification, heatwaves and rising sea levels -- is not new.

Scientists noticed that large volcanic eruptions had similar effects and the 1991 eruption on Mount Pinatubo in the Philippines lowered temperatures around the world for two years.

For decades the theory was dismissed as dangerous until Crutzen, who won the 1995 Nobel Prize in Chemistry for research on ozone, published his paper.

"Until August this was a taboo issue. But the paper I published really set off some movement in this area. It never hit the level of seriousness which it has taken in the past months. It may have had to do with the Nobel Prize, but I hope that's not all," Crutzen said.

Some critics say the project is too risky and will have negative effects on the earth's water supply and increase acid rain.

Crutzen said it was necessary to study the negative consequences, but he did not expect a rise in acid rain because the amount of sulphur injected would be a small percentage of the sulphates polluting the lower atmosphere today.

Some environmental groups, wary of geo-engineering projects, say the idea should at least be looked at.

"The fact that the top experts in the field are saying it's necessary shows it's a sad state of affairs," said Steve Sawyer, a policy adviser for Greenpeace International.

"This idea should be examined and as a last resort it can buy us a few decades," Sawyer said.

Crutzen's argument is essentially: Given that our industrial production is responsible for ~40% more greenhouse gases (e.g. CO2) than would occur naturally, the only reason we're not welcoming our hot Venusian warlords is because aerosols (e.g. smoke) is also generated as part of it. That nasty smog we try so hard to avoid and get rid of has actually prevented an even more dramatic shift -- it's called the "parasol effect", and as we get better at cleaning our air, global warming will get proportionately worse. Now, aerosols at breathing level are bad for any number of reasons <cough cough>. But, is there some way to selectively deploy aerosols way high up as a sunscreen?