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Forget the Melting Arctic, Sea Ice in Antarctica is Growing!

The sea ice that covers the Arctic Ocean has plummeted to its lowest level on record — but down at the other end of the world, the sea ice surrounding Antarctica has swelled. That’s no surprise, considering that winter is just ending in the Southern Hemisphere — but what may be surprising is that the overall extent of Antarctic ice has grown by about 1 percent per decade, on average, since satellite records began a little over 30 years ago.

You might reasonably suspect that all the fuss about disappearing Arctic sea ice is overblown, then, given the growth of ice down south.

But you’d be wrong, for all sorts of reasons.

Credit: US Embassy New Zealand

The first is that the 1 percent growth per decade in the Antarctic pales next to the much faster 15.5 percent drop per decade in the Arctic. They aren’t even in the same ballpark. Not only that: while the sea ice bordering Antarctica has been growing slightly, the massive ice sheets that sit directly atop the frozen continent are shrinking, at an accelerating rate, with worrisome implications for global sea level rise.

The disparity is even more dramatic when you realize that most of the sea ice surrounding Antarctica drifts away during the summer to melt in warmer waters, and reforms anew in the winter. The Antarctic sea ice cover is nearly all first-year ice, which is typically 3 to 6 feet thick. In the Arctic, by contrast, the ice is hemmed in by Canada, Alaska, Russia and Greenland. It mostly can’t drift away, so whatever is left behind at the end of summer gets even thicker the following winter.

That multi-year ice, which can be up to 15 feet thick and is much harder to melt, dominated the Arctic Ocean when satellites first went into orbit back in 1979. If you look at the volume of ice rather than just the area it covers, the disparity between the Arctic ice loss and Antarctic ice gain is just that much more impressive.

Still, if the planet is warming, how can the sea ice be expanding in the waters surrounding Antarctica in the first place? Keeping in mind that it isn’t expanding by much, scientists offer several possible explanations. One is that there’s been more precipitation in recent decades (which itself could well be due to global warming). That puts a cap of relatively fresh water atop the denser, saltier water below, and in winter, when that top layer cools, it stays on top rather than mixing with the warmer water underneath, thus encouraging the growth of ice.

Trends in Antarctic sea ice cover. Click on the image for a larger version.
Credit: Cryosphere Today.

Another factor may be the ozone hole that opens up at this time every year over the South Pole. Ozone loss tends to cool the upper atmosphere — an effect that percolates down to the surface.

Still another factor is purely natural climate variation, which is still happening even though manmade global warming has a growing influence on every aspect of the Earth’s climate system with every passing decade.

In any case, climate scientists have long expected that the Arctic would warm up faster than the Antarctic. After all, the former is an ocean surrounded by land, while the latter is land surrounded by ocean. Wind patterns, weather systems and ocean currents behave differently at the two poles. And because the coldest part of the Antarctic is land, the ice there has been able to accumulate into a giant ice cube the size of a continent and up to two miles thick — which tends to hold back local warming considerably.

By the second half of the century, however, climatologists say that the human warming signal will become more apparent, and Antarctic sea ice will begin to follow its Arctic cousin in a downward spiral. That, in turn, could speed up melting of the all-important Antarctic land ice, thereby raising global sea levels.

Related Content 
Study Finds Ice Sheets Becoming Dominant Contributor to Sea Level Rise 
The Bad News Continues to Flow About Antarctica's Ice 
Antarctic Ice Melt: The Big Picture


By Todd Russell (Des Moines, IA 50324)
on September 22nd, 2012

Thank you for the article.

I wish more people would learn some of the science behind Global Warming.  There is an excellent website where interested people can learn about The Discovery of Global Warming.  It was created by Spencer Weart.  You can find the site here:

This is from his chapter on the Modern Temperature Trend:

Talk radio callers and right-leaning columnists continued to exclaim about one or another unusually cold winter in this or that locality. They pointed out that some regions showed no warming at all, notably the massive Antarctic ice sheet. This was no surprise, but an effect predicted as far back as 1981 by Stephen Schneider and a collaborator. Noting that the Southern Hemisphere was mostly ocean, which would tend to take up heat and delay the rise of atmospheric temperature in the region, they had warned that people “may still be misled… in the decade A.D. 2000-2010” by cool weather there. (It turned out, however, that this and later computer studies were too conservative: in the 2000s, regions around Antarctica began to show a bit of warming and significant loss of ice.)

Quite a prediction from over 20 years ago.

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By Eric (22903)
on June 7th, 2014

My thoughts:

Lying discredits your position.  Omitting things that don’t help your argument discredit your position.

There is no way to take the earth’s temperature. It’s too dynamic. The best we can do is take surface readings and compare them year after year. While it can be 80 degrees one hour it could drop to 40 degrees the next.

The Global Warming crowd would have some credibility if the loudest mouth wasn’t raking billions off carbon credits and gov’t grants.

Michael Mann omitting the Roman warm period and the medievil warm period as well as refusing to allow scientific method to check his work brings the entire movement into question.  Especially when the CRU emails showed collaboration in hiding the decline in temperatures.

The one thing that average person has is his or her memory of life and the weather they experienced. Winters like 2013-2014 will no doubt make a lot of people throw AGW theory into the garbage.

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By Rudy Haugeneder, Canada (Victoria, BC, Canada)
on September 22nd, 2012

The problem with the pace of man-caused Climate Change is that it is happening slowly enough to simply become part of the new normal—a changing baselines—that the public meekly accepts.
That, unfortunately, is the way it is, meaning nothing of real consequence towards halting Climate Change will occur until after it becomes totally obvious that the threshold was long ago passed.

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By Doug Brockman
on September 22nd, 2012

I guess I should worry about the climate change and the coming dearth of polar bears.

But the last one we ate was pretty tough.

Plus, the livers are rather toxic.

So I doubt I will miss them too much.

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By Clive Mitchell
on September 23rd, 2012

Is warming measured by temperature? But in a sea-ice situation, the temperature remains almost constant - more heat means less ice, less heat means more ice.

If there is less heat and the water is all frozen, the ice temperature will go down. (Is anyone measuring the Antarctic ice sheet temperature?) If there is more heat until the sea ice is all gone, then the temperature will rise dramatically.

It seems that 2012 left enough energy in the system to melt a net 900 cubic kilometres of ice in the Arctic. Melting 900 cubic kilometre of ice into about 825 km3 water requires enough energy to raise around 65,000 cubic kilometres of (pure) water by 1 degree C. Dividing by the area of the Arctic Ocean gives enough energy to warm the top 4m by 1 degree C. Since it’s sea water, say a couple of metres in one year. Then the heat has to go somewhere else before the same happens the next year.

With around 3500 cubic km left this summer, if the net volume loss continues then the above scenario will take place within four years, without taking decreasing albedo into account.

Assumes PIOMAS data correct. The above model is called rule-of-thumb.

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By Stephen MacLean (Anchorage, Alaska 99518 )
on September 23rd, 2012

This article misses the point altogether.  It compares the MAXIMUM (end of winter) extent of seasonal ice in the Antarctic to the MINIMUM (end of summer) extent of sea ice in the Arctic basin.  The seasonal ice around Antarctica largely disappears each southern summer.  The Arctic basin used to be dominated by multi-year ice that remained through the summer.  Now, the multi-year ice is mostly flushed out of the Arctic basin, leaving one-year ice that does not last the summer and, viola, the Arctic basin becomes much more free of ice and open to transport through the Northwest and Northeast Passages, and much more absorptive rather than reflective of radiation.  So let’s stop making this silly non-comparison!

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By Mike Lemonick (Princeton, NJ 08544)
on September 23rd, 2012

Stephen MacLean reminds us that the comparison between winter maximum and summer minimum is an artificial one, which is quite true. Unfortunately, the idea is being bandied about that it’s somehow significant, so we went to great lengths to explain a number of of reasons why it isn’t. We did hint at the summer vs. winter problem in the first paragraph, but not as explicitly as we could have, so the reminder is much appreciated.

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By DirkH
on September 24th, 2012

Which physical mechanism makes the Antarctic land ice sheets shrink at an accelerating rate while temperatures stay below zero? I’m curious. Name it. Magic?

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By Erax
on September 24th, 2012

It’s amazing how you can take a swipe at ‘Talk radio callers and right-leaning columnists,’ while ignoring ‘left leaning’ people such as Al Gore and James Lovelock who were equally wrong. And surely you know they’re all after audience?

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By Jean SIREYJOL (Bordeaux France)
on September 24th, 2012

Sorry, but the headline is completly confusing, because it will be used by basic climate negationist. These people don’t mind that the content of the article explains that the headline is wrong.
Whatever. The headline will have done its job; creating confusion, while the global warming evidence is crystal clear.

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By Harold Chaytor (UK)
on September 25th, 2012

Any obvious comments on the below article:

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By Mike Mangan (Comstock Park, Mi. 49321)
on September 25th, 2012

NASA says that Antarctica is gaining mass…

James Hansen was adamant years ago that the greatest effects of global warming would be felt at both poles. The South Pole is neither heating up nor losing ice mass. Surrounding sea ice anomalies are well above normal. Your hypothesis has been falsified.
Oh, who am I kidding? Your hypothesis has a “moving goal posts” provision. No matter what conditions develop in any part of the globe, it’s all “consistent with” climate model predictions.

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By AlexJ (OR)
on September 25th, 2012

And what time frame did Hansen give for it being “felt” at both Poles, Mike? Source? The West Antarctic ice sheet is what is currently being affected by warming, while heat uptake elsewhere is apparently enough to put a damper on things. And per your referenced article, precipitation increases may have offset reductions in the Antarctic ice sheet as a whole over a period of relatively small climatic significance. But if memory serves, that follows a decrease in the five years prior. Antarctica is certainly a special case.

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By Robert Marston (20877)
on October 3rd, 2012

The southern hemisphere has yet to feel the full impact of human caused warming. For now, most of the major damage will be to the north. But, that said, Antarctca will begin to feel the effects of warming more and more as the years and decades progress. Deniers, as ever, stand on thin ice.

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By Ryan Maue (Atlanta GA 30346)
on October 15th, 2012

How does the austral spring ozone hole formation due to sunlight matter to winter sea-ice extent?

Ozone is a factor in Antarctic climate but how does that translate to when the sun is not shining?

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By mlemonick
on October 15th, 2012

Ryan Maue asks an excellent question. The ozone hole does open up in the austral spring, yet sea ice growth happens during the austral winter. But while the ozone does recover in winter, it doesn’t recover fully. Here’s a link to an explanation posted at the National Snow and Ice Data Center website (you have to scroll down to get to the Antarctic part)



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By Chris
on February 14th, 2013

Even if it is growing in the center.  The now warmer ocean waters are eating away at the ice flows and glaciers touching the ocean water.

Lots of glaciers down there touching the oceans -

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By Eric (Sarasota/Fl/33959)
on March 1st, 2013

Global warming is happening indeed , but not from mans ideas or transgressions. Its hard to imagine that everything is perfect in the universe that we round the sun in a perfect circle. Laws of mother nature do not deny that but it would make more sense that the earth is not only rotating east and west but maybe north and south too at a small rate. the axis point is changing thus the north side is rotating south causing warmer temps in the north and cooler temps in the south. Its almost elementary if you think about it. Many people are recording the sun positioning to be further north.They have also had coldest winters in south America than ever before. Use common logic for once people and stop belivies what people are telling you

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By Sarah Goodwich (Beverly Hills, CA 90210)
on March 14th, 2013

I’m still waiting for someone to explain the mechanism by which humans can produce any significant portion of climate-change, when the IPCC itself claims that we only account for 0.28% of total greenhouse gases, which is an insignificant portion.

The fact is that these “scientists” are either liars or idiots who weave a tangled web of deceipt and misinformation, with zero accountability for the damage they cause with reckless predictions.

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By Rodolfo Werner (Bariloche, Rio Negro, 8400)
on March 24th, 2013

I am amazed about some folks could be blind to the human made effects on our climate…and the impact on the melting of the sea ice in the Poles. Independently of the slight increase in “the overall” sea ice in Antarctica. It is important to emphasize the word “overall” since that word is misleading when one looks at the real effects on the sea ice in Antarctica.  While this could be true (the increase in sea ice) in some areas of the Antarctica, the situation of the area West to the Antarctic Peninsula is very different and dramatic. This area is one of the areas where the temperature has been increasing much more then in other areas of the planet, with the consequence of a large retreat in sea ice (in time and space; that is less sea ice and in a shorter period of time). This reduction on sea ice has strong implications on the spawning of Antarctic krill…that is, this has lead to a reduction in krill availability in this area. And it is important that Antarctic krill is the keystone species for the Antarctic food web. Parallel to this reduction of sea ice in the Antarctic Peninsula area (and also the shrinking of glaciers in this area) we are experimenting an important decrease in the population numbers of Adelie and chinstrap penguin in this area over the 30 years.  Thus, this information about a general increase in sea ice in Antarctica has to be analyzed in more detail.  And please, folks stop denying the existence of climate change induced by man made causes…

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By James (Eau Claire WI 54701)
on May 3rd, 2013

Dear DirkH:  Sublimation.

Look it up.

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By rob
on May 25th, 2013

This is a report where they throw numbers at you and nobody questions. If the ice is shrinking at 15.5% then 39.67% of the ice has disappeared in the past 30 years.This would be devestating if it were true. Anyone stop to think, wasn’t I taught in grade school that most of north america was swamp when dinosaurs were around? How is it that the climate cooled over millions of years and now that it is warming up it is our fault? We don’t know everything we claim to know and this theory has been used by many to make millions of dollars at the publics expense.

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