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Climate Paradox: Longer Antarctic Melt Season May Mean Less Global Warming

The views expressed are those of the author and are not necessarily those of Scientific American.


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Normally, the news that Antarctica’s summer melt season is getting longer might just be added to an endless compilation of scientific evidence that confirms the reality of global climate change. A recent research report, though, seems to run counter to the conventional wisdom. It shows that if the ice pack at the bottom of the world has more time to melt each summer, less of it might transition from solid to liquid.

Glacier ice shelves breaking up in the Antarctic

Glacier sea ice in the Antarctic, Credit: Pixabay.com

In fact, the study, published in the March issue of Nature Geoscience, found, the presence of a layer of slowly melting freshwater might actually help slow the melting process—as meltwater from Antarctica’s ice shelves increases in volume, it creates a cooler surface layer that shields the ocean from warmer, ocean strata below.

The study provides a compelling contrast to findings in the Arctic, where studies from the last 60 years have supported the idea that increased summer melting breaks up ice shelves, leading to a rise in sea level in the region. The maximum-recorded extension for the Arctic’s polar ice cap this year, on March 15, was the sixth lowest on record. All ten of the region’s lowest maximums have occurred in the past ten years.

But on the opposite side of the globe, sea ice has expanded dramatically in the austral autumn and winter months, achieving a record enlargement as recently as 2010. The scientists behind the study have come up with several theories to explain the southern sea ice expansion. More intense winds might reduce transfer of heat—one theory holds—and then go on to enhance overall cooling.  Another surmise: build-up of cold melt water may result from a negative feedback effect in which cooler ocean water protects sea ice from melting, which would, in turn, help offset greenhouse warming.

Using a coupled-climate model simulation called EC-Earth, which models both the atmosphere and oceans, the study’s scientists showed that the presence of increased accumulations of cool meltwater promote sea-ice expansion. Starting with the year 2000, the team performed a 31-year sensitivity experiment, adding an additional 250 billion tons of water each year to surface waters around Antarctica.

About the Author: Science, health and environment reporter based in Brooklyn, New York. Follow on Twitter @erbrod.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Carlyle 5:47 pm 04/1/2013

    Well at last The Antarctic gets a mention in these pages. I think the explanation is nonsense but at least they acknowledge the fact of Antarctic Ice growth. Antarctica has had 28% more maximum sea ice extent than the Arctic & the extent has been growing for thirty years yet rarely gets a mention.

    Link to this
  2. 2. bencorc 5:49 pm 04/1/2013

    “the reality of global climate change” doesn’t need “confirming”.

    The Earth has been warming since the peak of the last ice age, ~12,500 years ago:

    http://www.uvm.edu/whale/ChamplainGlacialHistory.html

    Link to this
  3. 3. erbarker 6:03 pm 04/1/2013

    Now he is a real climate paradox. What’s up with this?
    “OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO₂ put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.” http://www.economist.com/news/science-and-technology/21574461-climate-may-be-heating-up-less-response-greenhouse-gas-emissions

    Link to this
  4. 4. Buckwheat 6:14 pm 04/1/2013

    It is interesting to me that the scientists go back and tweak their models until it fits the data they have. This is not science, this is blatant scientific fraud. No one is sticking with their hypothesis other than, “Carbon is causing this.” I have seen all sorts of explanations as to why AGW is not happening like it was predicted 15 years ago. None of them hold water with me. But, there is a heck of a lot of money flowing to the scientist from Washington. In fact you can’t get a grant these days unless your technology is green or promotes carbon offsets. Someday in history we will look back at this as the most corrupt time in science. I’m not saying that AGW isn’t real by the way, I’m just saying no one has a way to say it is real or not one way or the other.

    Link to this
  5. 5. CharlesKaye 6:42 pm 04/1/2013

    This is laughable. The alarmist crowd will ignore this article, as they’ve ignored so much other evidence that demonstrates that their claim of man being the cause of “climate change” (the fraud formerly known as global warming) is nothing more than a ploy to advance their ridiculous agenda to control everyone through fear and ignorance.

    I’m going to save this article along with the one I have where Space.com stated that increased atmospheric CO2 actually REDUCED the amount of IR radiation reaching the Earth’s surface during recent increases in solar flare activity.

    The more we all know about how our world really works, the less these so-called “scientific intellectuals” can BS us.

    Link to this
  6. 6. MARCHER 6:51 pm 04/1/2013

    @5,

    Anyone who actually believes in some some vast conspiracy encompassing virtually every scientific institution on earth in an attempt to “advance their agenda to control everyone through fear and ignorance.”

    Would do better to head over to sites on psychology and review articles on disorders involving severe paranoia.

    Link to this
  7. 7. Humphrey Bogart 7:15 pm 04/1/2013

    It never ceases to amaze that “experts” stick with their original hypothesis regardless of evidence to the contrary. Isn’t it obvious that ice from the arctic has leaked down to the antarctic? Never fear. “Experts” will soon postulate about a hidden passageway between the arctic and antarctic since no ice has been observed gliding on the earth’s surface on a journey south.

    Link to this
  8. 8. moss boss 8:04 pm 04/1/2013

    @Carlyle:

    From what I can find, sea ice extent has only increased three percent in the last three decades. Please provide a citation.

    Regardless, there is a reason focus is placed upon the Artic; It is at sea level and is a much better barometer in measuring change. The reason Antartica is of less service to forecasters, and objective climate research in general, is that it has the highest average elevation of any continent, and the elevation varies. I know that you are commenting regarding sea ice extent, but you have lied about it and, thus, have rendered your arguments obsolete.

    http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice_south.php

    Link to this
  9. 9. jctyler 8:05 pm 04/1/2013

    “Climate Paradox: Longer Antarctic Melt Season May Mean Less Global Warming”

    funny

    Link to this
  10. 10. moss boss 8:15 pm 04/1/2013

    @erbarker, Buckwheat, and Bogart:

    The 15 year theory is utter bullshit and to think that scientists hold more clout in the economic rat-race than oil executives fails to acknowledge who has more to lose.

    Link to this
  11. 11. Carlyle 8:19 pm 04/1/2013

    We are specifically talking about sea ice. nothing to do with the land. Yes the average over the last three decades is 1% per decade. That does not tell you what the average over the past decade or the past five years is come to that.

    Link to this
  12. 12. moss boss 8:26 pm 04/1/2013

    @Carlyle:

    I fail to understand your comment. Please elucidate. I still do not know why you referenced a specific number of 28 percent. Explain your reference, and provide a citation (as I already asked).

    Link to this
  13. 13. DaniEder 8:33 pm 04/1/2013

    @Carlyle – The Arctic has lost on average 87,000 km^2 of sea ice per year, while the Antarctic has gained 10,000. So the combined ice cover has decreased by 77,000 km^2 annually.

    One reason for increased southern ice is that fresh water from continental sources (glaciers) has a higher freezing point than salt water, by 2C. Therefore it will freeze sooner and melt later.

    Link to this
  14. 14. davidotazu 8:55 pm 04/1/2013

    @CharlesKaye

    It is also important to immunize yourself against the BS resulting from ignorance. CO2 is an infrared absorbing gas and the sun emits at the infrared wavelengths. However, the greenhouse effect refers to the changing of shortwave solar radiation into longwave (infrared) AFTER it hits the earth’s surface. So if you were to compare the amount of incoming infrared radiation to the amount of outgoing infrared radiation, it would be the outgoing infrared radiation that would dominate. Therefore, a CO2 increase in the atmosphere would result in a net increase in the greenhouse effect.
    Also, the Space.com article was referring to CO2 levels in the thermosphere, which is very different from CO2 levels in the lower atmosphere.
    Please make sure you refer to accurate information as well as have an accurate functional understanding of the topic before you post. Otherwise, the internet would be filled with even more trash.

    Link to this
  15. 15. Carlyle 8:56 pm 04/1/2013

    The average total sea ice extent of both poles is about 12 million square miles. The total over the past winter at the two poles was substantially over 13 million square miles. About 13.4 million from memory.

    Link to this
  16. 16. moss boss 9:03 pm 04/1/2013

    @Carlyle:

    You have not provided a reference to your claims. I ask you a third time. If anyone is to take you seriously, you must not dodge questions by changing the subject.

    Link to this
  17. 17. Carlyle 2:42 am 04/2/2013

    Look it up yourself. do you have to be spoon fed? Wikipedia states the average combined polar sea ice at about 12 million square miles. You can look up the extent of each polar ice extent for the latest winter seasons & add them together & you will find the answer yourself. Also when you get the arctic figure you can do your own calculation & see for yourself how much greater the Antarctic sea ice is. If you do not have the maths, get your teacher to help. I am not your teacher. By the way, sault claimed that the Arctic sea ice maximum was many times larger than the Antarctic maximum on another article. Wrong again but no retraction. Your guru is a false prophet.

    Link to this
  18. 18. Carlyle 2:53 am 04/2/2013

    1. 41. sault in reply to Carlyle12:42 AM 3/26/13
    More denier bunkum. The arctic ice cap is SEVERAL TIMES the size of Antarctic sea ice
    http://www.scientificamerican.com/article.cfm?id=do-global-tipping-points-exist
    Perhaps you might like to inform your hero that he is wrong after you look it up yourself.

    Link to this
  19. 19. RokShox 6:11 am 04/2/2013

    “Another surmise: build-up of cold melt water may result from a negative feedback effect in which cooler ocean water protects sea ice from melting, which would, in turn, help offset greenhouse warming.”

    This is staggeringly incorrect. If the ice doesn’t melt, then the heat that would have melted the ice is retained in the ocean, enhancing global warming.

    Link to this
  20. 20. syzygyygyzys 6:16 am 04/2/2013

    I wonder if you folks realize that every post you enter here shows up on Google as a separate hit when you search for your moniker. A small number of you make up the majority of the posts here for the last several years. And you are experts on everything!

    I’m adding this comment in case it helps someone new to reading comments.

    Link to this
  21. 21. RokShox 6:46 am 04/2/2013

    “[Arctic] melting breaks up ice shelves, leading to a rise in sea level in the region”

    There are no ice shelves in the Arctic. All the ice in the Arctic is floating and its melting has ZERO effect on sea level.

    Oh crap. I got it. April Fools. I get caught every year.

    Link to this
  22. 22. RokShox 6:49 am 04/2/2013

    So how come “accumulations of cool meltwater” in the supposedly melting *Arctic* have not “promote[d] sea-ice expansion”?

    Link to this
  23. 23. Carlyle 8:07 am 04/2/2013

    Re: 13. DaniEder 8:33 pm 04/1/2013
    I do not have an answer to your comment. I have not had time to research it. A possibility that comes to mind that may explain the discrepancy could be that the Antarctic sea ice may have expanded much more rapidly in recent years & that the average you refer to predates the present situation. I suspect the rate of 1% per decade increase for Antarctica may not reflect or record the rate of increase for the past few years. Certainly I have read recently that the combined maximum extent had surpassed the historic record. Unfortunately I have no been able to relocate the reference or confirm its veracity. Certainly your question is valid. Perhaps someone with a little more time may be able to research it & inform us.

    Link to this
  24. 24. Carlyle 9:27 am 04/2/2013

    8. moss boss 8:04 pm 04/1/2013
    Your link is 13 years out of date. On this basis you called me a liar. When you learn to find the latest figures you might like to reconsider that accusation. There are those on these forums for whom that accusation is much more appropriate.

    Link to this
  25. 25. Jim Clarke 10:40 am 04/2/2013

    When scientists make up stuff like this, they can create a lot of problems for themselves in the future. First of all, there is no mention of any actual data other than sea ice extent. Did they measure the surface salinity around the Antarctic to see if it was decreasing? Apparently not. Did they measure an increasing flow of fresh melt water under the ice? Apparently not. Did they measure an increase in the atmospheric temperature over the Antarctic that might lead to more melting? No…not over 98% of the continent. Secondly, the rough waters around the Antarctic continent quickly mix the fresh and salt water.

    This is not science. It is a mental puzzle. How can we explain more ice in the Antarctic while maintaining our belief in AGW? Those are the parameters that guided the construction of their computer model. The model does not ‘reveal’ anything other than what it was programmed to reveal, just like every other climate model.

    So here is the tangled weave resulting from this practice of deception: What does it mean if Antarctic ice starts to slowly decrease? Could it be global warming? NO! Based on this study, less ice would be a sign of Antarctic cooling. The cooling would produce less melting, which would keep the surrounding ocean saltier, allowing for less ice!

    By the way, the sea ice around Antarctic has expanded for all seasons, not just “austral autumn and winter months”, as the article claims. Yes, even during the melting season. This years minimum was the second largest ever recorded, and 5 of the largest minimums have occurred in the last 10 years! I wonder why they didn’t mention that?

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

    Link to this
  26. 26. Carlyle 3:44 pm 04/2/2013

    3. erbarker 6:03 pm 04/1/2013
    Re your link: http://www.economist.com/news/science-and-technology/21574461-climate-may-be-heating-up-less-response-greenhouse-gas-emissions
    Thanks. Excellent.
    Also 25. Jim Clarke 10:40 am 04/2/2013 Logic will win in the end. Great post. There have been others too who have provide thought provoking comments & genuine contributions to the debate. Most enjoyable.

    Link to this
  27. 27. RokShox 4:07 pm 04/2/2013

    @moss boos et al., in addition to quantitative data you can find regarding sea ice areas and extents, here is a nice set of videos which allows you to visualize the actual sea ice on a daily basis since the beginning of the satellite era for both Arctic and Antarctic.

    http://noconsensus.wordpress.com/2013/03/28/cryosphere-sea-ice-video/

    I note in the Arctic a key contributor to ice loss is the amount that flows out of the Arctic along the east and west coasts of Greenland. That is all a matter of the strength and direction of the wind.

    Link to this
  28. 28. G. Karst 4:33 pm 04/2/2013

    As to the question of total sea ice, one will find the total sea ice trend, at the very bottom of this graph (red) here:

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg

    There is no question that there is more sea ice area than the mean. Area, not volume is all that matters regarding albedo. GK

    Link to this
  29. 29. Dr. Strangelove 10:17 pm 04/2/2013

    Jim Clarke

    Sea ice in Antarctica neither prove nor disprove global warming because the Antarctic ice sheet accounts for less than 1% of earth’s surface heat capacity. 96% of the heat is in the oceans. Antarctica may be cooling but it doesn’t mean all the oceans are also cooling. It depends on how heat is distributed on the entire earth’s surface.

    A better indicator of global temperature is mean sea level rise. Excluding the effect of melting glaciers, the rise is due to thermal expansion of seawater. The sea is a gigantic natural thermometer more accurate than the thermometers in weather stations, which measure air temperature. The atmosphere accounts for only 0.1% of earth’s surface heat capacity.

    Link to this
  30. 30. Carlyle 10:41 pm 04/2/2013

    That would be true if it was possible to measure accurately on a global scale. that is extraordinarily difficult. Although satellites take measurements in very fine detail, they do not take measurements at the same instant globally. There are many factors that have to be factored in to the raw data, wind & tide plus gravitation anomalies affecting both orbital heights & ocean depths as well as tectonic or land heights. When you are dealing with only a few millimetres per annum, the task is extraordinarily difficult. The Argos system with thousands of buoys has been operating for thirty years & the increased temperatures forecast simply have not been found. there is speculation that there is an increase in ocean temperature below 700 metres but no satisfactory explanation as to what mechanism could carry warmer, therefore lighter water down below colder denser water. That is totally opposed to normal convection that works in the opposite way. In short, the explanations are convoluted. Occam’s razor seems to dictate that if you can not find it, it probably is not there. If it is below 700 metres, how can it affect our present climate?

    Link to this
  31. 31. Dr. Strangelove 12:03 am 04/3/2013

    Sea level is easier to measure than air temperature. It is measured on decadal changes and on geologically stable areas to eliminate other factors. Thermohaline circulation mixes cold deep water with warm surface water. It could take decades or centuries to mix completely. That’s why thermometer measurements above 700 m depth are no good. Sea level rise is better because it represents heat content all the way down.

    Water below 700 m affects present climate because it has biggest heat capacity. 1C change in air temp. translates to 0.001C change in ocean temp. It’s too small, it’s undetectable using thermometer. Deep oceans can take huge amount of heat undetected. Unless you’re measuring sea level.

    Link to this
  32. 32. Carlyle 4:56 am 04/3/2013

    The sea levels attributed to satellite measurements do not tally with terrestrial long term tide gauges in geologically stable sites. The terrestrial sites record significantly less ocean level increase than the satellites. So which level do you use for your thermometer? If you are a climatologist, whichever is the largest. Easy really.
    Increased temperatures in the ocean depths are the subject of speculation & have not been confirmed by the Argos buoys. You do not often hear about the buoys because they do not support the climatologists theories I suspect.

    Link to this
  33. 33. Dr. Strangelove 10:33 pm 04/3/2013

    If it is true as you said that satellites measure greater sea level rise than terrestrial sites, then that indicates greater warming. As I said, thermometers cannot measure heat changes in deep sea. More sea level rise means more heat in the oceans.

    Link to this
  34. 34. greenhome123 1:02 am 04/4/2013

    We still have a lot to learn about the climate, but one thing is certain – burning fossil fuels pollutes our air and water. I like to breathe clean air and eat seafood from clean water. So, I am in favor of most regulations that reduce air and water pollution.

    Link to this
  35. 35. juliokes 1:59 am 04/4/2013

    Olivia. I just agree… Donald`s article is neat, I just bought a new Mercedes after making $4456 this last month an would you believe $10,000 last-munth. this is definitely the best work Ive ever done. I started this 4 months ago and almost straight away startad making at least $85, per hour. I follow this website, FAB33.COM_only

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  36. 36. sault 2:03 am 04/7/2013

    Why do you continue to LIE, Carlyle? I said that the DECREASE in Arctic sea ice is several times the size of the INCREASE of Antarctic sea ice. Still no apology from you. And the link moss boss’ link is 13 years out of date only if you’re dumb enough to not hit the “play” button or SCROLL DOWN a few lines to see data from 2012. How much do fossil fuel companies pay you per post, Carlyle?

    Link to this
  37. 37. Dvaytw 9:12 am 08/20/2013

    I find it utterly astonishing that so many people are driven by ideology to subscribe to conspiracy theories that one can’t read a single AGW-related article without finding adherents to such garbage crawling all over the comments section. Some of you fellas need to learn some basic epistemology, so you’ll know how ridiculous you sound. The key phrase here is ~dis-confirming evidence~. You haven’t bothered to seek it. Any AGW denialist talking point you can toss out can be demolished at the Skeptical Science website, among others.

    Link to this

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