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22 Nov 2010

The Warming of Antarctica: A Citadel of Ice Begins to Melt

The fringes of the coldest continent are starting to feel the heat, with the northern Antarctic Peninsula warming faster than virtually any place on Earth. These rapidly rising temperatures represent the first breach in the enormous frozen dome that holds 90 percent of the world’s ice.
By fen montaigne

In 1978, when few researchers were paying attention to global warming, a prominent geologist at Ohio State University was already focused on the prospect of fossil fuel emissions trapping heat in the Earth’s atmosphere. His name was John H. Mercer, and when he contemplated what might be in store for the planet, his thoughts naturally gravitated to the biggest chunk of ice on Earth — Antarctica.

“If present trends in fossil fuel consumption continue...” he wrote in Nature, “a critical level of warmth will have been passed in high southern latitudes 50 years from now, and deglaciation of West Antarctica will be imminent or in progress... One of the warning signs that a dangerous warming trend is under way in Antarctica will be the breakup of ice shelves on both coasts of the Antarctic Peninsula, starting with the northernmost and extending gradually southward.”

Mercer’s prediction has come true, and a couple of decades before he anticipated. Since he wrote those words, eight ice shelves have fully or partially collapsed along the Antarctic Peninsula, and the northwestern Antarctic Peninsula has warmed faster than virtually any place on Earth.

View photos
Adélie penguins Antarctica

Photo by Fen Montaigne
Adélie penguins have been particularly hard-hit by the rapid warming of the northwestern Antarctic Peninsula.
The question now, as humanity pours greenhouse gases into the atmosphere at an accelerating rate, is not whether Antarctica will begin to warm in earnest, but how rapidly. The melting of Antarctica’s northernmost region — the Antarctic Peninsula — is already well underway, representing the first breach in an enormous citadel of cold that holds 90 percent of the world’s ice.

Much attention has rightly been paid to the precipitous warming of the Arctic, where Arctic Ocean ice is rapidly shrinking and thinning, Greenland’s large ice sheets are steadily melting, and permafrost is thawing from Alaska, to Scandinavia, to Siberia.

But none of the earth’s ice zones, or cryosphere, can compare with Antarctica, which is 1 ½ times the size of the United States — including Alaska — and is almost entirely covered in ice, in places to a depth of three miles. The Antarctic accumulated this unfathomable volume of ice because it is a continent surrounded by ocean — the Southern Ocean — which acts like a great, insulating moat around the South Pole. The Arctic, by contrast, is an ocean surrounded by continents, whose landmasses moderate the polar climate.

How cold is the Antarctic? How about -128.6 degrees F cold, which is the lowest temperature ever recorded on Earth, as measured at the Soviet Antarctic base, Vostok, on July 21, 1983. The polar plateau, where legendary explorers such as Robert Falcon Scott perished, routinely records temperatures of -70 or -80 degrees F in winter. So it will be quite some time before the heart of Antarctica’s vast ice dome begins to melt.

The periphery, however, is another matter, and steady warming there has the potential to raise global sea levels many feet and to affect global ocean circulation.

No place on the fringes of Antarctica has warmed with the swiftness of the Antarctic Peninsula, a crooked, 900-mile finger of land that juts toward the tip of South America. A 60-year temperature record on the
‘We are going to get to a point where sea ice won’t form anymore, and that could be catastrophic.’
northwestern Antarctic Peninsula, taken at a research base originally built by the British and now run by the Ukrainians, paints a stark picture: Winter temperatures have increased by 11 degrees F and annual average temperatures by 5 degrees F. Ninety percent of 244 glaciers along the western Antarctic Peninsula have retreated since 1940. Sea ice now blankets the Southern Ocean off the western Antarctic Peninsula three fewer months a year than in 1979, according to satellite data.

In addition, ice shelves — large slabs of ice that flow off the land or out of submarine basins and float atop the ocean — have been disintegrating up and down the peninsula. The most notable breakup occurred in early 2002, when several summers of warm weather heated up the surface of the Larsen B Ice Shelf, creating countless melt ponds that enabled warmer water to seep down into the ice shelf. That led in March 2002 to what’s known as a “catastrophic” break-up; the ice shelf, once the size of Connecticut, shattered in a matter of days.

“We are already at the point where the changes we’re seeing in this part of Antarctica are unprecedented throughout the entire period of human civilization,” said Ted Scambos, the lead scientist at the National Snow and Ice Data Center in Boulder, Colo.

The level of warming in Antarctica is far more severe than global warming of the past century, which has been about 1.4 degrees F. One major cause is that the warming of landmasses and oceans to the north has set up a sharper contrast with Antarctica’s intense cold. That has led to a strengthening of northerly winds, pulling far warmer air down from the south Pacific and south Atlantic onto the Antarctic Peninsula.

“One of the fundamental laws of thermodynamics is that heat always goes from warm to cold,” said Douglas Martinson, an oceanographer and Antarctic specialist at Columbia University’s Lamont-Doherty Earth Observatory.

Click to enlarge
Melting on Antarctica

NASA Goddard Space Flight Center/University of Washington/US Geological Survey
Warming across Antarctica, 1957-2007
The physical changes — especially the drop in sea-ice duration — have had major ecological effects. Ice-dependent organisms, including certain species of phytoplankton, are declining where sea ice is disappearing. The most important link in the Antarctic food chain — ice-dependent Antarctic krill, on which just about every seabird or marine mammal in Antarctica feeds — also appears to be in decline. (One study suggested that krill in the southwestern Atlantic sector of Antarctic waters had fallen by 80 percent, but other krill specialists think the decline is not nearly so steep.)

At the top of the Antarctic food chain, Adélie penguins are suffering where warming is most pronounced. Not only is their winter feeding platform — sea ice — shrinking. But the main components of their diet — Antarctic krill and Antarctic silverfish, both of which are ice-dependent — are in shorter supply. As a result, Adélie penguin populations in the northwestern Antarctic Peninsula have plummeted by 75 percent and more. Ice-avoiding species, such as gentoo and chinstrap penguins, are moving in.

“We are seeing the creation of a new ecosystem for which there is no precedent,” said Hugh Ducklow, a phytoplankton specialist at The Ecosystems Center at the Marine Biological Laboratory in Woods Hole, Mass. and head of a major long-term climate change study along the western Antarctic Peninsula. “There is an entire, distinct ecosystem just living in and on the ice. So as sea ice begins to decline and then fails to form, as is now happening very rapidly, all these organisms that depend on the timing and the existence and extent of sea ice for their successful feeding and breeding will be high and dry. If the warming continues, we are eventually going to get to the point where sea ice won’t form anymore, and that would be catastrophic to the system.”

Not only are air temperatures rising. Changing atmospheric and oceanic circulation patterns around Antarctica have caused the deep, Antarctic
If the Western Antarctic Ice Sheet eventually melts, sea levels could rise by 16 to 20 feet.
Circumpolar Current to be funneled up onto the continental shelf in western Antarctica. In winter, that water can be as warm as 37 degres F, which sounds cold, but in fact is considerably warmer than the surface water — which hovers around 32 degrees F — and vastly warmer than air temperatures, especially in winter. This huge volume of relatively warm water on the continental shelf is having an enormous impact, since water holds 1,000 times more heat than air.

“This Circumpolar Current water is just blisteringly hot,” said Martinson, speaking in relative terms. “The penguins down there will have to put on baggies and sunglasses!” In Martinson’s mind, rising ocean temperatures have played the key role in the warming of the Antarctic Peninsula and the melting of ice shelves, glaciers, and sea ice.

Of particular concern to scientists is the effect of this warmer water on the Pine Island and Thwaites glaciers, located at 75° South, below the Antarctic Peninsula. Robert Bindschadler, a senior fellow at the Goddard Space Flight Center and an expert on Antarctic ice, believes that the warmer waters are melting the submerged undersides of the ice shelves attached to these glaciers, causing them to grow thinner; in places, the Pine Island Ice Shelf is thinning at a rate of 160 feet a year, and the melting is effectively loosening the grip of the Pine Island Glacier on the sea floor, causing the vast river of ice behind it to accelerate into the sea. The Pine Island Glacier is now charging into the Amundsen Sea at a rate of about two miles a year.

Bindshcadler said that if all the ice from the ice streams feeding the Pine Island and Thwaites glaciers were to flow into the Southern Ocean, global sea levels could increase by five feet, inundating low-lying coastal areas from Florida to Bangladesh. Such an event, he said, could happen in the next half-century. Should the ice from the far-larger Western Antarctic Ice
A longtime researcher expects Adélie penguins to disappear in the region in his lifetime.
Sheet eventually melt, global sea levels could rise by 16 to 20 feet, according to Bindschadler and other researchers.

The biggest repository of Antarctic ice is on the polar plateau and the enormous ice sheets of East Antarctica. Although some studies have shown that most of Antarctica is cooling slightly, the most comprehensive survey to date — published last year in Nature — showed that Antarctica overall warmed 1 degree F between 1957 and 2007. Some inland areas in West Antarctica have warmed by 2.7 degrees F. That warming has extended to the Transantarctic Mountains, just several hundred miles from the South Pole.

The changing atmospheric circulation patterns around Antarctica have, in places, dragged more frigid air off the polar plateau and cooled some parts of the continent. One portion of the Ross Sea, for example, is colder and has actually seen sea ice grow in recent years.

But Antarctic climate experts say the long-term temperature trend in Antarctica is almost certainly heading straight up, which is bad news for the continent’s two ice-dependent penguin species — the Adélie and the far-larger emperor, featured in the movie “March of the Penguins.”

MORE FROM YALE e360

Keeping a Watchful Eye
on Unstable Antarctic Ice

Keeping a Watchful Eye on Unstable Antarctic Ice
NASA’s Robert Bindschadler, who is part of an international team monitoring a large and fast-moving glacier in West Antarctica, explains the dramatic impact this unstable mass of ice could have on global sea levels.
READ MORE
One of Antarctica’s premier penguin researchers, David Ainley, and two colleagues recently forecast the impact on these two polar penguin species if global temperatures rise 2 degrees C — 3.6 degrees F — above pre-industrial levels, something that almost certainly will occur this century. They concluded that Adélie and emperor penguin colonies north of 70° South — comprising half of Antarctica’s 348,000 pairs of emperor penguins and three-quarters of the continent’s 2.5 million pairs of Adélies — “are in jeopardy of marked decline or disappearance, largely because of severe decreases in pack-ice coverage and, particularly for emperors, ice thickness.”

Bill Fraser, who has devoted three decades of his life to studying penguins and other seabirds on the northwestern Antarctic Peninsula, has seen populations of Adélie penguins in his study area fall from more than 30,000 breeding pairs in 1975 to 5,600 pairs today. He expects Adélies to disappear in the region in his lifetime.

“They’re on a decline,” he said, “that has no recovery.”

ABOUT THE AUTHOR


Fen Montaigne is senior editor of Yale Environment 360 and author of the recently published book, Fraser’s Penguins: A Journey to the Future in Antarctica. His work has appeared in The New Yorker, National Geographic, Outside, Smithsonian, and other magazines.
MORE BY THIS AUTHOR

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COMMENTS


I first wintered at Palmer Station, on the west side of the Antarctic Peninsula, in 1995. That year the ocean froze solid from July through October. We were skiing on sea ice around nearby Arthur Harbor, in and around ice bergs, to Torgersen Island to see the penguins (1km), and over to the Old Palmer site (1.5km). It was so solid we could have skied to the distant Joubin Islands (8km).

Since then things appear to have warmed dramatically. I wintered again in 1999, 2006 and 2007, and each time the weather was warmer, wetter, and the sea ice thinner. In '06 and '07 the ocean never froze solid enough to ski on. The glaciers next to the station have receded and many of the Adelie penguins have disappeared.

It's still a very beautiful place, but the changes in just the past 15 years have been stunning. During that same time the Larsen A, Larsen B, and Wilkins ice shelves along the Peninsula have also collapsed into the ocean.

The Peninsula appears to be changing from an ice landscape into a water world. And fast.

Posted by G. Grant on 22 Nov 2010


If Antarctic is getting warmer, why is Antarctic sea ice near an all time high?

Misrepresenting the Antarctic peninsula warming as typical of the entire continent is not only wrong, it is purposely misleading.

Posted by mark on 22 Nov 2010


To G. Grant, your argument has 2 distinct logic flaws.

First, any argument that tries to use a regional phenomenon to disprove a global trend is dead in the water. Anthropogenic global warming theory does not predict uniform warming throughout the globe. We need to assess the balance of the evidence.

In the case of this particular region, there is actually very little data about the changes in the
ice sheets. The growth in the East Antarctic ice sheet indicated by some evidence is so small,
and the evidence itself so uncertain, the sheet may well be shrinking.

But even this weak piece of evidence may no longer be current. Some recent results from
NASA's GRACE experiment, measuring the gravitational pull of the massive Antarctic ice
sheets, have indicated that on the whole, ice mass is being lost.

Second, ice-sheet thickening is not inconsistent with warming! Warmer climates tend toward
more precipitation. The Antarctic is one of the most extreme deserts on the planet. As it warms, we would expect it to receive more snow. But even a whopping warming of 20 degrees -- say, from -50 degrees C to -30 degrees C -- would still leave it below freezing, so the snow wouldn't melt. Thus, an increase in ice mass.

While on the subject of ice sheets: Greenland is also growing ice in the center, for the same
reasons described above. But it is melting on the exterior regions, on the whole losing approximately 200 km3 of ice annually, doubled from just a decade ago. This is a huge amount compared to changes in the Antarctic -- around three orders of magnitude larger. So in terms of sea-level rise, any potential mitigation due to East Antarctic Ice Sheet growth is wiped out many times over by Greenland's melting.

Posted by Rutherfordbhaze on 22 Nov 2010


Mark,

While sea ice may be increasing in part of the Antarctic, that increase is cancelled out by the
lost ice elsewhere in the region. When you hear a global average or a regional average for things like global warming, sea level rise, or ice melt, that number is a composite of what will happen. For example, global warming projections don't mean that temperatures will increase the same amount everywhere--they describe the average of all the changes that will occur locally. Most places will see some amount of regional average temperature increase above or below the global average temperature increase, but some places may even see their regional average temperature go below the current value. But the trend is strong enough that in the global average, it balances those extremes out.

Just like with your high school grades, you can get one F but still have a passing grade point
average if you have enough passing grades.

Average does not equal actual.

Posted by Shana on 22 Nov 2010


Is it merely a coincidence that the Antarctic Peninsula is underlain by near subsurface geothermal activity which is warming adjacent ocean waters? Is it merely coincidence that melting of the Pine Island Glacier, which is responsible for at least ten per cent of global sea rise, is due to geologic not climatic changes?

Posted by enermisly@yahoo.com on 22 Nov 2010


G. Grant's question was actually about Antarctic SEA ice rather than land ice.

The sea ice extent definitely has increased slightly, but given that this extent is the area of OCEAN which has at least 15 percent ice coverage that doesn't mean the AMOUNT of sea ice has increased. A larger 'extent' can also come about because the ice is more spread out... as might happen as currents shift due to the warming ocean water. Even if the actual ice coverage increased (which hasn't been established) the amount of ice might still be the same (or less) if thickness decreased. Also, the breakup of all those ice sheets and increased glacier flow is now dumping alot of ice into the Antarctic oceans... where it becomes 'new sea ice'.

Thus, pointing to a tiny increase in Antarctic sea ice extent as basis for denying Antarctic warming is groundless. There is no contradiction between the two.

Posted by CBDunkerson on 23 Nov 2010


You people slay me.

Antarctic sea ice simply refuses to melt, and stubbornly remains at a very high level. In fact in 2010 it reached its second highest level ever since satellite measurement began over 30 years ago. Normally Antarctic sea ice peaks at about 18.3 million sq km around September 20.

But this year, Antarctic sea ice reached that value already on about August 9 or so – over 5 weeks early!

http://notrickszone.com/2010/11/19/antarctic-ice-explosion/

Posted by Carbonicus on 23 Nov 2010


Ditto Carbonicus: Notice how the alarmists dogde and weave to avoid addressing the truth. There is more sea ice in Antarctica and it didn't get that way because it is warmer in the surrounding ocean.

But in the alarmist's world, more ice and less ice both provide more proof for their CO2 is evil beliefs. Same goes with more rain and less rain, more snow and less snow.

For years we have heard about more hurricanes caused by CO2 and global warming, and this year's storms reached a thirty year low. Surely one of the warmists can point out why, even though they forecast more storms and storms are at a record low, it still proves that CO2 is in control.

Since nothing is likely to be done to reduce CO2 unless a scientist figures out how to make energy from something other than carbon based fuel, it seems to me that the warmists should be appearing in those sandwich boards: "The end is near - repent now"

Posted by cagw_skeptic99 on 23 Nov 2010


“The penguins down there will have to put on baggies and sunglasses!” - that's an interesting
image. If only equipping our Spheniscidae friends with surfing attire were a serviceable solution.

Posted by Jimmy G on 25 Nov 2010


Comments by Carbonicus & CagSkeptic reveal the Deniers' typical refusal to examine all data. The previous comment by CBDunkerson clearly states that Sea Ice EXTENT measured by satellites does not take into account actual Sea Ice VOLUME. In other words, what you see on the surface doesn't reflect how much is actually under it.

Deniers typically do the same thing: look at the surface, and ignore what's underneath. Which is what leads to ignorance.

Then they call others Alarmists, which is quite amusing. Too bad that even the informed & the innocent (especially our children) will all have to pay for the consequences of the ignorant who deny that any problem exists.



Posted by sky2evan on 26 Nov 2010


Historically warming gases (i.e. from natural sources) have had a dramatic effect on the weather and always will, this is basic science and not in contention.

The fact remains that the models we use to predict climate change are incomplete interpolations, just take normal weather forecasting as an example, we have had some real discrepancies and long term forecasting is generally very difficult and inaccurate.

So, how will the effects of CO2 be felt?

Why take that risk?

Posted by on 29 Nov 2010


Feynman would be scratching his head. There's no missing sea ice here:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png

Posted by John Garrett on 29 Nov 2010


Hey Jon Garret, turns out there is some missing ice here. Now here's basic science question, "Which has more impact on sea level rise, sea ice or land ice?"

http://www.jpl.nasa.gov/news/features.cfm?feature=2378

Posted by sc0tt on 30 Nov 2010


Looking at this picture :
http://e360.yale.edu/content/images/pine-island-image-3.html

This is obvious that the full portion on the left will break, you don't need to work in the building structure industry or being a scientist to foresee it.

I will say it again, the issue is that you scientists are not able to communicate in the proper
manner. First you don't have a homogeneous sound and second your support for communication sucks. Don't take it as a critics, you need to do something on that, 50 percent of your job is to analyze, 50 percent of it is also to communicate correctly. If global warming occur and it should, you will be partially responsible for not having been able to be organized as a community and communicate correctly. There are new tools to communicate including social networks and you should use them.

I lived in Asia for 5 years and every year the weather gets more humid and hotter. Any local
action can't fight a structural phenomenon, the answer has to be global. Given that we tend to focus on economic indicators and that protectionism is rising.. we have a problem .. but it needs to be solved, no ?

Posted by julien chabe on 02 Dec 2010


Climate change is no longer a communication problem. The people who can be convinced are already convinced. A fraction will vacillate depending on the weather, another fraction does not want to know and the remainder refuse to be convinced by any amount of evidence. This division is being exploited by those with vested interests in the fossil fuel economy.

The situation is unlikely to substantially change until supply constraints and alternative technologies eventually make fossil fuels uneconomic.

Posted by Greg on 02 Dec 2010


Long before fossil fuels the climate changed, warming and cooling. For millions of years these changes were not influenced by human activities.

Why make the assumption now that humans are to blame? If fossil fuels were completely forbidden and completely removed as a contributing factor, what impact would occur over the next million years?

Posted by A. Miller on 07 Dec 2010


A. Miller, There is a lot of available scientific information addressing your questions, but I think you are basically answering your own first question with the phrase "millions of years".

It took millions of years for all those plants and animals to absorb and store that carbon in the geology of the Earth. Humans are now in the process of taking all that carbon and putting back into the atmosphere in a scant couple of hundred years. That's going to have some consequences.

Posted by Sc0tt on 08 Dec 2010


True, all of these variables - people, time, carbon cycle, ocean currents need to be looked at relative to each other. You have to acknowledge that humans have a capability that no other organism has; To dig down into the earth and release in a day what took millions of years to form. Is there any way to correlate what volcanic activity contributes to the equation?

Posted by Graham on 09 Dec 2010


From Graham: "Is there any way to correlate what volcanic activity contributes to the equation?"

Yes, volcanic eruptions can inject large amounts of aerosols into the Stratosphere causing a short term (several years) cooling effect at the Earth's surface. This is because less than the average amount of sunlight is reaching the surface of the Earth, causing temperature in the Stratosphere to rise where the radiation is being absorbed. The 1991 eruption of Mt. Pinatubo enabled a good collection of data on this effect.

Posted by Sc0tt on 09 Dec 2010


On a recent Alaska Vacation the guide stood in front of a melting glacier stating various statistics about the daily melting of all the glaciers. The guide painted a dismal picture linked to global warming.

At the conclusion the guide stated the last time the glaciers melted was 3000 yrs. ago - long before fossil fuels or the internal combustion engine!

Posted by A. Miller on 10 Dec 2010


RE: A. Miller

You're taking an overly simplified view of the cycles of the Earths climate in relation to what's happening today. Again, as I responded above, try taking into account the rate of change. You can't just look at the absolute change regardless of time. There are also many other multiple lines of evidence in the physical science basis attributing recent global warming to human activity. Just saying, "Well, the climate changed before human industrial activity so it must just be natural now", is not a compelling scientific argument.

I guess I have to agree with Greg's comment above.

Posted by Sc0tt on 14 Dec 2010


As others have noted, Antarctic sea ice extent is sharply above average. There is evidence that global temperatures are leveling off or dropping after the run up associated with the solar maximum conditions of the late 20th century. The longer solar cycles we are experiencing currently have been associated with colder climate going forward. The positive feedback assumptions necessary for CO2 to cause harmful warming have been debunked by Lindzen and Spencer.

Best of all, with the Republican ascendancy there is absolutely no chance of limitations on CO2 emissions. CO2 levels will keep going up and due to ongoing solar influences the earth's climate will cool. CO2 as a cause of harmful warming will be debunked in yet another way.

Posted by aurelius on 14 Dec 2010


RE: aurelius

Come on now, your comments are just deliberately misleading. While Antarctic sea ice extent may have increased, land ice volume has also decreased.

There is evidence that the total solar irradiance over the past century can not explain the rise in global temperature. Research shows with high probability that a doubling of CO2 in the atmosphere will lead to a 1.2degC rise in directly CO2 caused global warming. Additionally, melting ice and increased evaporation of water will act as positive feedbacks increasing warming another 1degC.

http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/044.htm

The assertions of Lindzen and Spencer that cloud formation will produce enough of a negative feedback to offset future warming are not robust and are heavily criticized. In fact, recent studies by Dessler and Lauer add confidence that the cloud feedback is not significantly negative, and may actually be positive, supporting the high end of current estimates of global climate sensitivity.

Your comments are the exact type of anti-scientific ramblings designed to create doubt about the actual scientific evidence and prevent immediate mitigation strategies. Sigh.

Posted by Sc0tt on 15 Dec 2010


In response to those readers who have suggested that Antarctica has not experienced significant warming because sea ice extent there is at an all-time high, I would like to point out the following. First, the article stressed that along the western Antarctic Peninsula, which is warming rapidly, the key at this point is sea ice duration, not sea ice extent. Incontrovertible evidence, as measured by satellite, shows that from 1979 to 2006, sea ice duration along the western Antarctic Peninsula has declined by nearly three months, depriving Adélie penguins of an important feeding platform. As the story pointed out, sea ice duration has actually increased in the western Ross Sea, due to shifting atmospheric patterns in that region that are pulling more frigid air off the polar plateau and over the western Ross Sea.

Sea ice extent around Antarctica has increased since 1979, but not to a significant degree. As my article noted, Antarctica remains a uniquely cold spot on the planet. But the point of the story was that rising temperatures along the Antarctic Peninsula represent the first significant warming of this icy continent. Sea ice extent along the western Antarctic Peninsula, as measured by satellite, is declining, due to sharp increases in ocean and air temperatures. The overwhelming majority of polar ice specialists are confident that as industrial activity continues to warm the planet, both sea ice extent and duration around Antarctica will decline, as is now happening rapidly in the Arctic Ocean.

Posted by Fen Montaigne on 15 Dec 2010


That Ainley paper on penguins talked about "ice obligate" species such as the Adelie and Emperor. "Ice obligate" means the species require sea ice at specific times during their lives. Their fate, which appears very uncertain, led me to think about the fate of a certain "planet obligate" species I happen to be a member of.

One of Ainley's co-authors is Joellen Russell. She thinks the change in the Antarctic Circumpolar Current (ACC) "is one of the most significant trends in the global climate system over the past 20 yr". This phenomenon "caught geoscientists by surprise", she says.

Ozone depletion and global warming are working together to cause an intensifying "thermal contrast in the middle of the atmosphere". The result is 20% more powerful Southern Westerlies which have shifted towards the South Pole by 6 degrees of latitude, "like a shrinking donut". The intensification was "not predicted".

Because the new position of these winds is more closely aligned with the land-free band of ocean all around Antarctica more energy is applied to drive the more powerful ACC. This current was already four times more powerful than the Gulf Stream. It is the only place on the planet where water from the deep ocean wells upwards.

One result will be increased mixing of the deep ocean with surface waters which may act as a bit of a brake on the average global surface temperature chart as more heat is conveyed into the deep ocean. Russell is a modeller: she is also finding that more CO2 ends up in the ocean over time if the ACC remains as strong as this. She believes a countervailing force is an increased global hydrological cycle.

Her comment on sea ice: changes are due to the strengthening Westerlies which drive more of the slightly warmer water from the deep ocean to the surface - "we see melting right where we expect to see it on the Antarctic peninsula, growth of sea ice where it is coldest in the Ross Sea, and these are exactly what one would expect from anthropogenic climate interference both from the ozone perspective and greenhouse gas warming".

See:

Ocean Circulation in a Warming Climate, Toggweiler and Russell

Impact of Westerly Wind Position on the Circulation of the Southern Ocean Russell et.al.

The Southern Hemisphere Westerlies in a Warming World: Propping Open the Door to the Deep Ocean Russell et.al.

Posted by David Lewis on 16 Dec 2010


This discussion is great!!

It's simple and its kind of sad that the scientists are so narrow minded they can't take in the whole picture. Increased energy in the form of warmer waters is just that - more energy.

The more energy manifest itself as more vapor and more severe weather patterns. Mother nature has a magnificent and wonderful way to dissipate energy in the form of storms (hurricanes, typhoons and blizzards) that includes the conversion of water to ice/snow that dissipates much of that energy.

The scientists refuse to acknowledge this phenomenon.

That YES the "volume of ice" might be decreasing but the coverage might be expanding. And what happens when the coverage expands? More sunlight is reflected and the earth will cool.

Its quite an amazing thing honestly. I'm not going to get religious in here but the earth is quite an ingenious design. We don't give it enough credit or respect.

Posted by jabberwolf on 20 Dec 2010


RE: jabberwolf

The expanding coverage around Antarctica is not significant. Also, coverage is sharply decreasing in the Arctic. I think you may be putting too much confidence in Earths ability to adapt to the forcing humans are applying over such a short timescale. Humans are creating the problems and have to be the ones to solve them; Earth is resilient but will not take care of them on its own.

Posted by Sc0tt on 05 Jan 2011


As a retired science writer/editor (at Johns Hopkins), I'd like to point out something all scientists take so for granted they seldom think of it and never mention it, because to mention it sounds dumb. That means they never get to point out its unpleasant corollary, which is central to the present debate. Here it is, in a version that the public can understand:

Natural mechanisms compensate so splendidly that, in effect, it's as if the systems are devoted to maintaining a viable status quo. It's like a dance: Up-regulators and down-regulators, by the dozen or hundreds or thousands, adjust, adjust, and adjust some more, in response to one another. It's amazing and beautiful, just as Jabberwolf has said.

Take two tiny examples: if you become anemic, your heart speeds up a little, keeping what iron there is on the move, and the body gins out more red blood cells, but smaller. You feel fine, just a little short of breath—till one day you faint. Likewise, if you develop cancer, healthy cells tend to move meekly out of the way. It's a fact any adult past 40 knows: When cancer is caught because there were symptoms, such as intestinal blockage, it's late late late. Even heroic measures may fail.

Which clarifies the unpleasant corollary of Nature's splendid compensation: whenever a natural system shows symptoms, the deterioration is late, late, late. Symptoms, in and of themselves, are ominous.

It seems to me that tells us everything we need to know about climate "heating" (as James Lovelock calls it). Deterioration is well advanced, and atmospheric carbon dioxide released by humans is a player. THE player? A MAJOR player? Who cares. It's late. We know that because the planet is no longer able to compensate, which it does so well.

Humans have gotta stop making our contribution, or our grandchildren won't have a planet they can live on.

We could start by closing down all coal-fired plants and seeing how much energy we had, then learn to live on it. Weatherize our houses. Stop shipping meat 2,000 miles. Build public transit. It's really not so hard. We know enough to start.

Posted by Elise on 05 Jan 2011


Elise,
Your assertions are ominous. How about some specific facts regarding man made CO2.

Posted by A. Miller on 18 Jan 2011


The problem is mass consumerism. The wealthier nations are intent on consuming more than they need because their societal values and the structure of their economies encourage
consumption.

We need to see a substantial drop in consumer demand for manufactured goods world wide.

One way to do this is to reduce access to credit. Make cars less affordable and encourage people to walk.

Encourage media stars to tout the benefits of living with less.

Educate entire populations to eat vegetables and exercise more.

This will translate into reduced carbon emissions and slow global warming.


Posted by Roger D. White on 18 Feb 2011


Response to Roger D. White.

How about mandatory return to the "stone age"?

Posted by A. Miller on 22 Feb 2011


A. Miller,

If we continue upon the path we are on, I suspect we will one day wish for a life as comfortable as that of our stone-age ancestors.

Posted by Dave Baldwin on 03 Jun 2011


Steigs warming (Nasa-pic) has been debunked.

Journal of Climate
April 2011, Vol. 24, No. 8 : pp. 2099-2115

Posted by yo on 02 Aug 2011


Isn't it just human nature to disbelieve something so catastrophic that even life itself, plant and animal, could largely disappear? When in the history of mankind have we witnessed the poles melting together with all the mountain glaciers? But it's happening now due to mankind's greed and selfishness. So my question to the deniers is: what kind of evidence do you need to be convinced that world climate change is truly taking place?

Posted by Dan steeves on 13 Dec 2011


Amidst all the facts of global warming, certain facts are inctrovertible:
1. Glaciers on the moutains are retreating, and quite rapidly every year.
2. Arctic sea ice is shrinking and summer-ice may soon disappear.
3. Antarctic ice is more land-based, altitude driven, masssive but even here the edges are melting.
4. CO2 currently generated is about 50\% more than what the earth can absorb.

The only long term solution is sustainable living for all, including what is sustainable in fossil fuel burn. This means "intelligent" living and not primitive. The real question is how long is long-term?

Posted by Vinod Gupta on 27 Feb 2012



 

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