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Magnus Eisengrim
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Good news from Nature.

Quote:
The hole in the ozone layer over Antarctica is starting to heal, say researchers in Australia. The team is the first to detect a recovery in baseline average springtime ozone levels in the region, 22 years after the Montreal Protocol to ban chlorofluorocarbons (CFCs) and related ozone-destroying chemicals came into force.

Each spring, those chlorine- and bromine-releasing chemicals eat a hole in the ozone layer above the Antarctic. Thanks to the Montreal agreement, levels of anthropogenic ozone depleters detected in the region's stratosphere have been falling since around the turn of the millennium. However, detecting any corresponding ozone recovery has been difficult.

That difficulty is down to significant natural variations in average Antarctic stratospheric springtime ozone levels from year to year, which mean that the hole can be small one year and large the next. Scientists did not expect to be able to detect the gradual recovery of ozone for decades, masked as it is by these dramatic swings.

However, Murry Salby, an environmental scientist at Macquarie University in Sydney, Australia, and his colleagues have now shown how this annual fluctuation can be accounted for — and so removed from the data. They are left with the underlying systematic change in Antarctic ozone levels. Salby's calculations reveal that the levels are now rising; the findings are published in Geophysical Research Letters.

The team's breakthrough was in showing that annual swings in average springtime ozone levels are linked to changes in a particular pattern of stratospheric weather known as dynamical forcing. In years in which this phenomenon is strong during the winter, more cold air is trapped above the pole. As a result, there are more ice crystals in the atmosphere. These crystals form the surface on which chlorine destroys ozone, catalysed by sunlight returning to the Antarctic during the spring.

"I think this is the first convincing observationally-derived evidence of the ozone rebound," says Adrian McDonald, an atmospheric scientist at the University of Canterbury in Christchurch, New Zealand. "It's the first where the statistical significance is high enough, and you can see the pattern well enough, that you feel comfortable in believing it."

Salby's results reveal a fast decline in ozone levels until the late 1990s, then a slow rebound that closely matches what theoretical calculations had predicted, says David Karoly, a climate scientist at the University of Melbourne, Australia. "It is the sort of result that was expected, but is the first to provide detection of an increase in Antarctic ozone levels," he says.

Adding weight to Salby's argument, the increase in ozone levels revealed by the calculations closely mirror the decrease in the levels of anthropogenic chlorine in the region. "For now, they agree pretty well," says Salby. "My feeling is that as time goes on we will start to see other influences on the systematic evolution of ozone level beside chlorine." One such influence is likely to be the increasing concentration of carbon dioxide in the atmosphere.

Salby's data reveal that average springtime Antarctic ozone levels have already recovered by 15% since the late 1990s. However, projecting forward, natural weather-related fluctuations mean that even as late as 2085, ozone will still drop below 1980 levels for at least one year in every ten.

A complicating factor in that prediction is the influence of climate change, says Karoly. "Even when CFCs are removed, ozone levels will be different in the future than they were in the 1960s, because of changes in temperature in the stratosphere."

It's a relationship that goes both ways, however. "In the past four or five years it has become very clear that the ozone hole seems to have held back climate change over Antarctica," says McDonald. Ozone absorbs sunlight, so less ozone means the stratosphere heats up less. This has caused a change in circulation patterns around the Antarctic, which has trapped more cold air over the pole. As the ozone hole recovers, its future impact on Antarctic climate, and so on melting ice caps and global sea-level rise, is under debate.

"Some people are saying that, once the ozone hole totally recovers, because it has so far had a braking effect, maybe when that brake gets taken off then we'll have rapid change over the Antarctic. But there are many complexities in the system, and so other people are saying that it might not have very much effect. That is definitely work to be done by the climate-science community."

In the more immediate term, the strong correlation between winter weather patterns and springtime ozone levels means that the intensity of the ozone hole can now be forecast, says Salby. That is important because, at the end of each spring, the ozone-depleted air is released across the mid-latitudes of the southern hemisphere, affecting major population centres during the summer months by allowing increased levels of ultraviolet light to reach Earth's surface.

"If you know what the stratospheric forcing is during the winter, you can predict rather accurately the ozone level for the following spring," says Salby.
The blood-dimmed tide is loosed, and everywhere
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Dannydoyle
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So what is your position here John? Is it a good thing or should we be doing more or do we need a global tax or what? What is your exact position here?
Danny Doyle
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<BR>In a time of universal deceit, telling the truth is a revolutionary act....George Orwell
Magnus Eisengrim
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My exact position is that it appears that the scientific and governmental communities cooperated and have solved a potentially disastrous problem. I am very pleased.

What's your position, Danny?
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.--Yeats
landmark
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I'll just put in my usual bi-annual question meant to save a lot of wasteful repetition of argument. Of course, in reality, it probably won't change a jot in the course of this thread:

IF Global Warming were proven to be man made, THEN do you think any action should be taken to ameliorate it?


No sense arguing the first part, if you don't think any action should be taken either way.


See, I just saved everyone pages and pages of argument.
mastermindreader
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I think the post is an excellent illustration of what can be accomplished through cooperation to solve a potentially serious problem. No agenda. Just observation of facts.

Landmark- I think that even if every single reputable scientist on the planet confirmed AGW (actual scientists, not TV weathermen or a bunch of people with bachelors degrees in unrelated fields), there would still be those who, encouraged by political propaganda and bogus and distorted "research" propagated by certain corporate interests, would claim it was a massive hoax and would have no desire to do anything about it at all.
tommy
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Has it ever occurred to you that it might be normal?
If there is a single truth about Magic, it is that nothing on earth so efficiently evades it.

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rockwall
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Quote:
On Sep 10, 2014, mastermindreader wrote:
...
People like me? What's that supposed to mean? And note that I haven't used the word "science denier" since you claimed that you were offended by it, even though you do deny AGW science.

But really, what do you mean by "people like me?"


Well actually, I think it was Danny who finally got you off that kick but I'll thank you anyway.

People like you? Well, people who despite the fact that the global temperature has not gone BELOW the LOWEST point of what the IPCC was predicting still can't admit that maybe, just maybe, the computer models aren't all they're cracked up to be. And just maybe, accurately predicting what is going to happen in the future is just a bit tougher than they would like to admit. (I would think you of all people would know that!)
tommy
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NASA Reveals New Results From Inside the Ozone Hole
December 11, 2013

Media briefing slides associated with this story are available here.

NASA scientists have revealed the inner workings of the ozone hole that forms annually over Antarctica and found that declining chlorine in the stratosphere has not yet caused a recovery of the ozone hole.

More than 20 years after the Montreal Protocol agreement limited human emissions of ozone-depleting substances, satellites have monitored the area of the annual ozone hole and watched it essentially stabilize, ceasing to grow substantially larger. However, two new studies show that signs of recovery are not yet present, and that temperature and winds are still driving any annual changes in ozone hole size.

visualization of average zone hole in October 2013
The area of the ozone hole, such as in October 2013 (above), is one way to view the ozone hole from year to year. However, the classic metrics have limitations.


"Ozone holes with smaller areas and a larger total amount of ozone are not necessarily evidence of recovery attributable to the expected chlorine decline," said Susan Strahan of NASA's Goddard Space Flight Center in Greenbelt, Md. "That assumption is like trying to understand what's wrong with your car's engine without lifting the hood."

To find out what's been happening under the ozone hole's hood, Strahan and Natalya Kramarova, also of NASA Goddard, used satellite data to peer inside the hole. The research was presented Wednesday at the annual meeting of the American Geophysical Union in San Francisco.

Kramarova tackled the 2012 ozone hole, the second-smallest hole since the mid 1980s. To find out what caused the hole's diminutive area, she turned to data from the NASA-NOAA Suomi National Polar-orbiting Partnership satellite, and gained the first look inside the hole with the satellite's Ozone Mapper and Profiler Suite's Limb Profiler. Next, data were converted into a map that shows how the amount of ozone differed with altitude throughout the stratosphere in the center of the hole during the 2012 season, from September through November.

The map revealed that the 2012 ozone hole was more complex than previously thought. Increases of ozone at upper altitudes in early October, carried there by winds, occurred above the ozone destruction in the lower stratosphere.

"Our work shows that the classic metrics based on the total ozone values have limitations – they don't tell us the whole story," Kramarova said.


http://www.nasa.gov/content/goddard/new-......jyaNJNkg
If there is a single truth about Magic, it is that nothing on earth so efficiently evades it.

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Bob1Dog
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Wouldn't this thread be better addressed in the other global warming thread to keep it all in one place?
What if the Hokey Pokey really IS what it's all about? Smile

My neighbor rang my doorbell at 2:30 a.m. this morning, can you believe that, 2:30 a.m.!? Lucky for him I was still up playing my drums.
tommy
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No because John thinks he has found a bit of the argument he can win and wants to make a big show of it.
If there is a single truth about Magic, it is that nothing on earth so efficiently evades it.

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mastermindreader
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Quote:
On Sep 10, 2014, Bob1Dog wrote:
Wouldn't this thread be better addressed in the other global warming thread to keep it all in one place?


Not really. This was supposed to be about the ozone holes. While they certainly contribute to AGW, they create other problems as well. Unlike AGW, the ozone situation has been improved by bi-partisan and corporate cooperation.
mastermindreader
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Quote:
On Sep 10, 2014, rockwall wrote:
Quote:
On Sep 10, 2014, mastermindreader wrote:
...
People like me? What's that supposed to mean? And note that I haven't used the word "science denier" since you claimed that you were offended by it, even though you do deny AGW science.

But really, what do you mean by "people like me?"


Well actually, I think it was Danny who finally got you off that kick but I'll thank you anyway.

People like you? Well, people who despite the fact that the global temperature has not gone BELOW the LOWEST point of what the IPCC was predicting still can't admit that maybe, just maybe, the computer models aren't all they're cracked up to be. And just maybe, accurately predicting what is going to happen in the future is just a bit tougher than they would like to admit. (I would think you of all people would know that!)


As to the accuracy of the IPCC models, see:

http://www.skepticalscience.com/curry-mc......acy.html

They're far more accurate than you seem to think.

Apart from the computer models, the effects of global warming have been documented through empirical observation. The oceans continue to steadily warm despite the apparent atmospheric stall, and as a result, sea levels continue to rise. These are measurable phenomena and have nothing to do with the models.

No one here, as far as I know, has ever even bothered to challenge the fact of oceanic thermal expansion.

And note that even though I've stopped using the word "deniers," others continue to call those who accept the science far more offensive names, like "hoaxers," "scammers," etc.
Dannydoyle
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I only challenge if it is normal cycles and we have observed it for a minute portion of time. Nobody disputes this either.

Yea I noticed the continued name calling and am disappointed. You may have slipped once but the onslaught of warmer and alarmist has not subsided.
Danny Doyle
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<BR>In a time of universal deceit, telling the truth is a revolutionary act....George Orwell
rockwall
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Quote:
On Sep 11, 2014, Dannydoyle wrote:
I only challenge if it is normal cycles and we have observed it for a minute portion of time. Nobody disputes this either.

Yea I noticed the continued name calling and am disappointed. You may have slipped once but the onslaught of warmer and alarmist has not subsided.


Has anyone complained of being offended by the term warmist or alarmist? I assume that they would agree with those terms, just as I would not be offended by the term 'sceptic'.
Dannydoyle
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It is just too easy to forget a person with another viewpoint is still a person.
Danny Doyle
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<BR>In a time of universal deceit, telling the truth is a revolutionary act....George Orwell
Wizzard
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To much Kool-Aid here!

John
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mastermindreader
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Quote:
On Sep 11, 2014, rockwall wrote:
Quote:
On Sep 11, 2014, Dannydoyle wrote:
I only challenge if it is normal cycles and we have observed it for a minute portion of time. Nobody disputes this either.

Yea I noticed the continued name calling and am disappointed. You may have slipped once but the onslaught of warmer and alarmist has not subsided.


Has anyone complained of being offended by the term warmist or alarmist? I assume that they would agree with those terms, just as I would not be offended by the term 'sceptic'.


As an American I would be offended at being called a "sceptic" as the word has a different meaning here than in the UK. In the US "sceptic" refers to sewage, and "skeptic" refers to one who questions things. But, in any case, you're not a true skeptic since you continue to ignore evidence that is contrary to your preconceived notions, perfectly illustrating confirmation bias. something a true skeptic would never do.
rockwall
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Maybe you're thinking of septic.
tommy
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I think so.

A Septic Tank is a Chemical Toilet.
If there is a single truth about Magic, it is that nothing on earth so efficiently evades it.

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Slim King
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Greenhouse gasses fix Ozone problem!!!!! Smile
THE MAN THE SKEPTICS REFUSE TO TEST FOR ONE MILLION DOLLARS.. The Worlds Foremost Authority on Houdini's Life after Death.....
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