Computer models show major climate shift as a result of closing ozone hole

A new study led by Columbia University researchers has found that the closing of the ozone hole, which is projected to occur sometime in the second half of the 21st century, may significantly affect climate change in the Southern Hemisphere, and therefore, the global climate. The study appears in the June 13th issue of Science.

The Earth's ozone layer is located in the lower stratosphere, which lies just above the troposphere (which begins at the planet's surface and reaches up to about 12 km), catching harmful ultraviolet rays from the sun. Until late in the last century, widespread usage of household and commercial aerosols containing chlorofluorocarbons (CFC), unstable compounds which are carried into the stratosphere, lead to significant and rapid ozone depletion.

Due to the Montreal Protocol, signed by 191 countries, CFC production worldwide was phased out in 1996. Observations in the last few years indicate that ozone depletion has largely halted and is expected to fully reverse. As a consequence, the new study finds, the Southern Hemisphere climate change may also reverse. This would be a very tangible outcome of the Montreal Protocol, which has been called the single most successful international agreement to date, and would demonstrate how international treaties are able to make positive changes to the climate system.

"Our results suggest that stratospheric ozone is important for the Southern Hemisphere climate change, and ought to be more carefully considered in the next set of IPCC model integrations," said Seok-Woo Son, lead-author of the study and a postdoctoral research scientist at Columbia's Fu Foundation School of Engineering and Applied Science (SEAS).

The team of 10 scientists compared results from two sets of climate models, the first one used by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), released in late 2007, and the second from the Scientific Assessment of Ozone Depletion, published by the World Meteorological Organization in 2006. In their prediction of future climate, many IPCC models did not consider the expected ozone recovery and its potential impacts on climate change. The chemistry-climate models used for the 2006 Ozone Assessment, however, predict that the Antarctic ozone hole will achieve full recovery in the second half of this century, and that this may have profound impacts on the surface winds and, likely, on other aspects of the Earth's climate, including surface temperatures, locations of storm tracks, extent of dry zones, amount of sea ice, and ocean circulation.

In the past few decades, the tropospheric winds in the Southern Hemisphere have been accelerating closer to the planet's pole as a result of increasing greenhouse gases and decreasing ozone. This wind change has had a broad range of effects on the Earth's climate. The IPCC models predict that this effect will continue, albeit at a slower pace. In contrast, predictions made by the chemistry-climate models indicate that, as a consequence of ozone recovery—a factor largely ignored by IPCC models—the tropospheric winds in the Southern Hemisphere may actually decelerate in the high latitudes and move toward the equator, potentially reversing the direction of climate change in that hemisphere.

"We were surprised to find that the closing of the ozone hole, which is expected to occur in the next 50 years or so, shows significant effects on the global climate," said Lorenzo M. Polvani, one of two principle investigators and professor of applied physics and applied mathematics at SEAS. "This is because stratospheric ozone has not been considered a major player in the climate system."

Polvani and Son state that more research needs to be conducted to validate their results, and to fully understand how complete ozone recovery will impact the planet's changing climate. While previous studies have shown that ozone hole recovery could lead to a warming of the Antarctic, much work remains. For instance, the chemistry-climate models used in the 2006 Ozone Assessment Report do not include a full ocean circulation, which might affect surface temperatures. The interactions between a recovering ozone hole, increasing greenhouse gases, ocean currents, and other components of the climate system must still be explored in order to better understand how the Earth's climate will change in the future.

Source: The Earth Institute at Columbia University

Explore further

Fossil fuel drilling could be contributing to climate change by heating Earth from within

Citation: Computer models show major climate shift as a result of closing ozone hole (2008, June 12) retrieved 23 August 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Jun 12, 2008
Lets see, no tempurature rise in the last 10 years, none to be expected in the next 10 years, and now because we got ride of Ozone depleating chemicals, now the Southern Hemisphere will not face global warming.....IPCC has ignored a lot, but we are still being told we must fight Man Made Global Warming. The more we learn, the more it looks like that global warming is like a childs monster, seems real to the child, but it doesn't exist once you investigate it.

consequence of ozone recovery%u2014a factor largely ignored by IPCC models%u2014the tropospheric winds in the Southern Hemisphere may actually decelerate in the high latitudes and move toward the equator, potentially reversing the direction of climate change in that hemisphere.

Jun 12, 2008
"Denialists". I like that. So much more elegant than what I've been using.

Jun 12, 2008
Since real science is evidence based, unlike this "man made global warming" hysteria (follow the money - who's making it?), YOU resort to name calling instead of presenting EVIDENCE. THe climate is changing. Like it or not, it has always changed.
Maybe the failure of the sun to produce sunspots in the last few years, which contributes to climate change, is industrialized mans fault. Maybe not, but at least we all know it's Bush and Cheneys fault.

Jun 13, 2008
"Lets see, no tempurature rise in the last 10 years, none to be expected in the next 10 years"

What utter nonesense-the 3 hottest years since records began are 1998 2005 and 2007-how on earth does this translate into no heating in the last 10 years??
I keep seeing this claim being made here and elsewhere on the net -anyone else getting fed up with shills ???

Jun 13, 2008
"The earth is actually cooling". "Polar bears are doing just fine - in fact their population has doubled". "It's a conspiracay of the rich and powerful university researchers to suppress the opinions of the poor, naive Oil companies". "Sunspots did it". "There are as many glaciers expanding as shrinking".

All tacks that the denialists have taken time and again. All total BS. Unfortunately, pointing it out doesn't do any good.

Jun 13, 2008
I don't want to make my posts too long, so I'm splitting this stuff up. Anyway, here goes.

1) The Earth is actually cooling.

In the Skeptic magazine, Vol 14 No1 2008, they've published two articles, one by a denialist, one by a Pro-GW. The denialist publishes a graphic of global average temperatures, which very clearly shows temperatures going up. Important note: He's NOT DENYING THE TRUTH OF THE GRAPH! He's using it to discuss climate modelling, but he takes it as an accepted fact that it has a positive slope. Of course, this particular individual is intellectually honest and has allowed himself to be limited by, you know, "actual facts", so his arguments are a good deal less dramatic than most of the posters here. The graph is of course jagged, which leaves the denialists lots of room to point at the short little downward slopes and scream "SEE!! IT'S GOING DOWN!! IT'S GOING DOWN!!!". Yeah, for 6 months, before it continues its upward climb. Again, let me reiterate. This was not presented by a Pro-GW. It was presented by a denialist.

Jun 13, 2008
2) Polar bears are doing just fine

I've posted this before, but it bears (haha) repeating. Denialists, when quoting this "fact", are very careful to pick the 60's more or less as the starting point for their comparison. That's because the 60's (it varies by area) were when governments started to realize that rampant hunting was about to wipe the polar bear out, and started implementing protective laws. After that, the polar bear population rebounded dramatically -- no surprise when your chief predator abruptly stops predating and you've got all this nice empty tundra with nary a polar bear in site.

The point is that the "fact" is manufactured by picking the lowest population point they could find, one created by virtually wiping the animals out. If the denialists showed some basic ethics and picked the population numbers BEFORE they took a nose-dive, you'd find an entirely different result. But hey, why start paying attention to facts now?

BTW, as an aside, the population is going down now and has been for probably about 10 years. And even at its "peak" at the end of the 20th, it never came even close to recovering to pre-60's numbers.

Jun 13, 2008
3) It's a conspirary etc

This one is so silly, I don't know why I bother. The denialists want us to believe that a bunch of rich and powerful university professors have managed to suppress, out-maneuver, and out-politic the Bush administration AND all those poor, naive Oil Company executives who couldn't POSSIBLY survive in such a political battle, despite the literally billions of dollars at their disposal.

Give me a break.

Besides the inherent silliness, there's the fact that if this was about money, the way to make money is not to hustle for a $50k grant, but to go to the Oil companies and offer to write a denialist tract for a few mil. The fact that scientists (mostly) aren't doing this just indicates integrity.

And let's not forget that the Bush administration, which has been doing its best to pull funding, silence, suppress, deny, and so forth has now been FORCED to admit GW. Why? Presumably because of those rich and highly politically astute university professors who managed to lobby for it. Uh, yeah.

Jun 13, 2008
I didn't realize the global warming "denialists" were denying that the globe is getting warmer. I think you would have to be a fool to think that it isn't getting warmer. The debate lies in the cause of global warming. Out of all the natural disaster scares I can't believe this one takes the cake. The worst part is government is looking to make it into a money maker and everyone is so scared that they are falling for it. Seriously "carbon footprint tax?" Is humanity really this ignorant?

Jun 13, 2008
4) Sunspots did it

Usually but not always mentioned in the same breath as the little ice age. Unfortunately, in that case sunspot lows were associated with a drop in tempearature, and in this case with a rise. Oh well.

BTW, I use the word "associated" with care, because there've been quite a few sunspot cycles, and most of them don't produce any dependable, predictable associated temperature fluctuations, so we're a long long way from establishing any kind of causal relationship, either for or against.

Jun 13, 2008
5) There are as many glaciers expanding...

I've only seen this once, and as the Devil's DP Dictionary describes, I bristled with acute disbelief. Some nit in a letter to the editor, actually claimed this. Of course, he provided no references or specifics, but then that's really what we've come to expect from the denialists.

This particular argument is more interesting as an example of the denialists' systemic, well, "denying". Use whatever you have to, say whatever you have to, insult whoever you have to. Don't worry about facts, references, plausibility, contradiction with something you said yesterday, or any of that fact-based stuff.

The answer is in Mitch the troll's earlier tantrum about forcing him to give up his precious incandescent lightbulbs is TYRANNY! IT'S TYRANNY, I TELL YOU! TYRANNY! BOOGEDDY BOOGEDDY!

Or the guy who posted recently (can't remember the handle -- sorry) who posted that GW can have some positive effects, despite bad things happening to some other people elsewhere. I don't think he intended it to come across that way, but it did.

The reality is that denialists, by and large, are simply upset at the idea that they might be told they can't. Can't drive their hummers any more, can't toss their garbage out the window, can't leave their lights on all night, can't crank their air conditioning down to 65. And if it ends up hurting other people, or even our children, so what? I'm getting mine, babe. Looking out for #1.

That's the REAL denialist philosophy, IMO.

Jun 13, 2008
I didn't realize the global warming "denialists" were denying that the globe is getting warmer. I think you would have to be a fool to think that it isn't getting warmer. The debate lies in the cause of global warming.

Ah, if only you were correct. Unfortunately, that's a minority viewpoint. Mosts denialists are not taking the stance "We can't be sure how much of GW is our fault so we should proceed carefully", they're taking the stance "GW is a myth so you should all shut up". And they're doing it using good-facts instead of real-facts (anyone catch the reference?) and bogus arguments, which should be a huge red flag to anyone who thinks.

Jun 13, 2008
Speaking of good facts vs. real facts, there are plenty of 'good facts' coming out of NASA. If you look at the climate audit web site you can see hundreds of temperature sites situated in such a way that their temperature will be warmer than it used to be (ie near devices that output heat, or black top) such that a comparison of their past and present record is hopelessly distorted. We see NASA selectively adjusting their records with correction factors so that more recent temperatures appear normal. We see the media hyping small, visible changes to the glaciers, while ignoring the bigger picture of overall ice mass increasing.

People keep thinking that somehow the oil companies want to go crazy with production. However, that's not in their best financial interests--while supply appears constrained oil prices stay high. Think about it, if we allow them to increase production in an unlimited fashion, their profits go down because it appears there is more supply. It is in their best interests to keep supply appearing to be on a razor's edge, and have small disruptions spike the prices like crazy. They benefit from the current status quo, while the consumers and especially poor people are screwed. So, why would it be in their economic interest to fund deniers? The additional costs for some minor pollution controls look big, but they pale in the big picture compared to the additional profits they make when supply is constrained. So, they make a show of trying to increase supply and then go tsk tsk to Congress, the environmental regulations prevented us from increasing supply, while rolling in the dough from the inflated prices everywhere. OPEC constrains supply but they are more blatant about it. The various gas companies countries have a win-win scenario going on, as long as the market believes that supply is limited...if they defeat the environmental groups they get to avoid a one time cost and get a slightly bigger piece of the pie. The environmental groups win as money pours into their 'carbon offset' schemes, frequently of dubious value. So, let me repeat, oil companies win whether or not the environmental regulations get passed, only the consumers get screwed, the poor disproportionately.

Now, let me address one more 'good fact' as they say that all the science is settled, and the various opinions stated here. Check out petitionproject dot org to see 31,000 scientists who say the environmental groups are making this global warming up. I could go on to address various points, but that website is much more succinct.

In the meantime good luck trying to find anyone here in Seattle who believes in global warming, as we have had an abnormally cold year. The media is calling it "Juneuary" as we have yet to get close to our average high temp and it snowed a foot on the main highway to the east of the city earlier this week. People were shocked to see snowplows running at this time of the year.

Jun 13, 2008
A computer model said so?! Well, that changes everything. Wasn't the trend with most computer model to predict global cooling in the late 70s? Long term climate models are horribly inaccurate; there's just too many variables.

Us Denyists have sat through 'An inconvenient truth', could you Undenyists sit through this for us?
"The Great Global Warming Swindle"
Fantastic professional British series. Google Video has a good version. I was on the other side of the fence two years ago, but after watching this I'm never going back.

Jun 13, 2008
Speaking of good facts vs. real facts, there are plenty of 'good facts' coming out of NASA.

Too many items for me to quote individually.

First, thanks for posting a considerably more sober and thoughtful item than we normally see. Name-calling gets old after a while.

In reverse order, I'm in Vancouver and we're calling it Juneuary as well. In fact, I think it was a Vancouver TV station that first coined that. I'll arm-wrestle you for it if you want.

But as GW-advocates keep pointing out again and again, Global Warming doesn't just mean warming. It means a breakdown of 'tradional' expectations for climate. Warms get warmer, colds get colder, winds get windier. In the last couple of years we've had some of the wildest windstorms I've ever seen, and I ain't no spring chicken.

"Overall ice mass increasing": specific reference, please. Unfortunately, this topic is too full of people making claims just because they sound good, and hoping no-one checks up. Every SINGLE ice mass of any size that I know of is shrinking, and not just slightly.

Oil companies: nice argument, but misses the point. Of course oil companies don't want to too much supply. They want to stay on the peak of the supply/demand curve, where you get maximum profit per unit. Sell more, the price goes down. Sell less, the price goes up, but not enough to make up for the loss of unit sales. Are you saying you don't think a successful pro-GW campaign would affect that? Puh-leaze! Any kind of real traction in the pro-GW direction (we're actually just starting to see a teeny bit of it with gas prices right now) would knock hydrocarbon sales for a total loop. And no guarantee at all that the current oil giants would be on the cusp of any techno/social changes. Bottom line for the oil companies: status quo=no risk, change status = big risk.

NASA. Interestingly, the Pro-GWs are claiming that NASA's been hiding evidence of GW, and the denialists are claiming that NASA's been manufacturing evidence of GW. I guess that's the triumph of politics over reality.

Last item, and it's out of order, sorry. Re petitionproject, I'm far more impressed by Freeman Dyson's stance on GW, since he is a respected scientist and not given to hysterics or being influenced. He doubts GW and gives his arguments, and I have to believe that his arguments reflect the best well-researched well-thought-out arguments against GW. And they're just not very convincing, except as an exhortation to "make haste slowly", which I don't entirely disagree with.

Jun 13, 2008
A computer model said so?! Well, that changes everything. Wasn't the trend with most computer model to predict global cooling in the late 70s?

Solar system models place the sun at the centre now? Well, that changes everything...

Come off it. The implied argument here (and it's implied because you'd be laughed at if you came out and said it) is that because a theory 40 years ago, with much less information and much poorer computer resources said something different, that no model on any computer now or even a thousand years from now could possibly be right, even in principle.

Sarcasm *is* the highest form of humour, but only if used properly.

BTW, we've got to come up with something better than "undenyists" or "undenialists".

Jun 16, 2008
Did you just include ABSOLUTELY THE ENTIRE ARTICLE AND ALL FOLLOWUPS in a reply? The usenet ninjas will be visiting you presently....

Jun 16, 2008
err no some sort of bug when i posted and you cant edit or delete...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more