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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Antarctica is gaining ice
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Is Antarctica losing or gaining ice?

What the science says...

Select a level... Basic Intermediate

Antarctic sea ice is gaining sea ice but Antarctica is losing land ice at an accelerating rate, which has implications for sea level rise.

Climate Myth...

Antarctica is gaining ice

"[Ice] is expanding in much of Antarctica, contrary to the widespread public belief that global warming is melting the continental ice cap." (Greg Roberts, The Australian)

Arguments that we needn't worry about loss of ice in the Antarctic because sea ice is growing or even that sea ice in the Antarctic disproves that global warming is a real concern hinge on confusion about differences between sea and land ice, and what our best information about Antarctic ice tells us. 

As well, the trend in Antarctic sea ice is not a permanent feature, as we'll see. But let's look at the main issues first.

  • Sea ice doesn't play a role in sea level rise or fall. 
  • Melting land ice contributes to sea level rise. 
  • The net, total behavior of all ice in the Antarctic is causing a significant  and accelerating rise in sea level. 

Antarctic sea ice is ice which forms in salt water mostly during  winter months. When sea ice melts, sea level does not change.

Antarctic land ice is the ice which has accumulated over thousands of years in Antarctica by snowfall. This land ice is stored ocean water that once fell as precipitation. When this ice melts, the resulting water returns to the ocean, raising sea level.

What's up with Antarctic sea ice?

At both poles, sea ice grows and shrinks on an annual basis. While the maximum amount of cover varies from year to year, there is no effect on sea level due to this cyclic process. 



Figure 1: Coverage of sea ice in both the Arctic (Top) and Antarctica (Bottom) for both summer minimums and winter maximums. Source: National Snow and Ice Data Center

Trends in Antarctic sea ice are easily deceptive. For many years, Antarctic sea was increasing overall, but that shows signs of changing as ice extent has sharply declined more recently. Meanwhile, what's the relationship of sea ice to our activities? Ironically, plausible reasons for change may be of our own making:

  • The Southern Ocean is freshening because of increased rain and snowfall as well as an increase in meltwater coming from the edges of Antarctica's land ice (Zhang 2007, Bintanja et al. 2013). Together, these change the composition of the different layers in the ocean there causing less mixing between warm and cold layers and thus less melted sea and coastal land ice.

Against those factors, we continue to search for final answers to why certain areas of Antarctic sea ice grew over the past few decades (Turner et al, 2015). 

More lately, sea ice in southern latitudes has shown a precipitous year-on-year decline (Parkinson, 2019). While there's a remaining net increase in annual high point sea ice, the total increase has been sharply reduced and continues to decline. 

How is Antarctic land ice doing?

We've seen that Antarctic sea ice is irrelevant to the main problem we're facing with overall loss of ice in the Antarctic: rising sea level. That leaves land ice to consider. 

Shepherd et al. 2017

Figure 2: Total Antarctic land ice changes and approximate sea level contributions using a combination of different measurement techniques (IMBIE, 2017). Shaded areas represent measurement uncertainty.

Estimates of recent changes in Antarctic land ice (Figure 2) show an increasing contribution to sea level. Between 1992 and 2017, the Antarctic Ice Sheets overall lost 2,720 giga-tonnes (Gt) or 2,720,000,000,000 tonnes into the oceans, at an average rate of 108 Gt per year (Gt/yr). Because a reduction in mass of 360 Gt/year represents an annual global-average sea level rise of 1 mm, these estimates equate to an increase in global-average sea levels by 0.3 mm/yr.

There is variation between regions within Antarctica as can be seen in Figure 2.  The West Antarctic Ice Sheet and the Antarctic Peninsula Ice Sheet are losing  a lot of ice mass, at an overall increasing rate. The East Antarctic Ice Sheet has grown slightly over the period shown.  The net result is a massive loss of ice.

Takeaway

Independent data from multiple measurement techniques (explained here) show the same thing: Antarctica is losing land ice as a whole and these losses are accelerating. Meanwhile, Antarctic sea ice is irrelevant to what's important about Antarctic ice in general. 

Basic rebuttal written by mattking


Update July 2015:

Here is the relevant lecture-video from Denial101x - Making Sense of Climate Science Denial

 

Last updated on 31 January 2020 by BaerbelW . View Archives

Printable Version  |  Offline PDF Version  |  Link to this page

Argument Feedback

Please use this form to let us know about suggested updates to this rebuttal.

Further reading

Tamino compares and analyses the long term trends in sea ice data from the Northern and Southern Hemisphere in Sea Ice, North and South, Then and Now.

Update

On 20 Jan 2012, we revised this article upon learning it referenced an incorrect quote. We apologize to Dr. Michaels and to our readers for the error.

Comments

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Comments 101 to 125 out of 509:

  1. Thank you both DB and Steve!
  2. Here's another new paper on Antarctic ice (h/t Ari). A multivariate analysis of Antarctic sea ice since 1979.
    The work presented here indicates that Antarctic sea ice variability is a multivariate phenomenon and that the minimum, maximum, and mean SIE may respond to a different set of climatic/geochemical parameters. ... For Antarctica, similarities were found for the minimum sea ice extent, O3 minimum, and total solar irradiance, while the mean sea ice extent was associated with the global sea surface temperature, the global air surface temperature, the CO2 concentration, and the O3 depletion area. Near similar patterns were found among the maximum sea ice extent, the SOI, and the SAM.
  3. The idea that ozone depletion is responsible for the increase in Antarctic sea ice had a cold bucket of water thrown on it. See Has the ozone hole contributed to increased Antarctic sea ice extent? Sigmond & Fyfe, 2011.
    In this study we consider the impact of stratospheric ozone depletion on Antarctic sea ice extent using a climate model forced with observed stratospheric ozone depletion from 1979 to 2005. Contrary to expectations, our model simulates a year‐round decrease in Antarctic sea ice due to stratospheric ozone depletion.
    "Circulation changes, in part due to ozone depletion, are responsible for the increase in Antarctic sea ice," would seem more correct.
  4. Given the concerns on Bishop Hill I would suggest that Sks remove comments 3, 5 and any other early comments that were replying to this post before it was updated to make a definite distinction between land and sea ice. If Sks did, for example, write the response to comment 3 after updating the post, then (-Accusations of dishonesty snipped-), when it actually seems like they were pointing out that the original incarnation of this page was unclear and certainly incomplete. I hope the Sks team sees my point. Our 'side' of the debate is by far the stronger, supported as it is by the weight of peer-reviewed science, and so there need be no reliance on misinformation, no matter how small a nugget of misinformation it is. Therefore all humility and reticence must be shown on sites like Sks, and things like this that have been overlooked must be corrected. Not doing so risks giving those of an anti-science persuasion an excuse to focus on something other than the science! Of course, the current incarnation of this page is an excellent description of the state of Antarctic ice, no problems there.
    Response:

    [DB] Accusations of dishonesty snipped.

    "Therefore all humility and reticence must be shown on sites like Sks, and things like this that have been overlooked must be corrected."

    SkS endeavors to keep its focus on the science, not on rhetoric, ideology or invective.  Hue and cry from the "skeptics" on things transparently not based in science amount to little more than tone trolling and are typically ignored.

    However, your point is made, taken and noted.

  5. DB I see that the responses to the comments in question have been updated and the whole thing makes perfect sense now. Tone trolling should rightly be ignored, but IMO Bishop Hill did have a point, although they vastly overstated the significance of it. That Sks is coming under fire presumably means you're doing a good job, so keep it up!
  6. A recent paper suggest that there is not sufficient evidence to conclude that ice loss from Antarctica is accelerating. The paper is open acces and can be found here: Zwally and Giovinetto, 2011 It seems to be in conflict with the statements in this post as well as he recent paper by Rignot et al, 2011 Does the Zwally paper hold any merits and should it be incorporated in the post?
  7. SRJ at 23:12 PM on 29 September, 2011 The Zwally paper re-assessing the data is later than Rignot, and the science is persuasive (in my view). Although in Zwally the estimates of average mass loss have been revised and reduced over the whole continent, there is even less doubt about increasing loss of land based ice in western Antarctica. The linkage with temperature rise in this area is perhaps obvious.
  8. # 107 Peter Hogarth Thank you for the response. When you write that there is even less doubt about increasing loss of land based ice in western Antarctica, what do you then base that on? The Zwally paper? Another question, in Zwally the estimated overall ice loss is 31 Gt/year. Could the cause for this be an decrease in precipation over Antarctica?
  9. Is there a possibility that the earth's axis has moved marginally i.e the North Pole is now slighty closer to the sun thus warmer there but colder in the south creating more ice in the Antartic. Wouldn't this also explain the changes in the magnetic fields that some scientists have apparenty noticed? i do believe that the recent earthquakes in Japan were strong enough to move the axis of the Earth albeit a small amount.
    Response:

    [DB] If you think about this you'll be able to answer your own question.  Any astronomer in the world can tell you that there's no evidence whatsoever for it.  GPS systems would be way off.  The tides would be different.  Satellites that measure earth changes to sub-millimeter accuracy would also provide evidence against it.  There is simply no physical evidence to cause such a shift that would not also be felt the world over.

    The crustal displacement/polar wander fancies of Hapgood are just that: flights of imagination.

  10. I have come across this comment on a thread at WUWT. "Although the Alarmist arguments sometimes include claims about ice volume, such claims are based upon sea ice extent and subjective guesses about what they beleive a model parameterization adjustment should be to produce a desired result. Currently, there are no objectively quantitative ice volume measurements with anthing remotely close to the necessary temporal and spatial coverages. Consequently, Morano and anyone else can only make objective observations about sea ice extent." Is there any validity to this guys argument? Thanks
  11. Look at the gravity probes measurements over Antarctica. They clearly and unequivocally show a loss of mass at an accelerated rate. No models no fitting, just good old empirical unadulterated data. And if somebody thinks that the rocks have been vaporizing, then think again. Mass loss -> Ice mass loss -> Ice volume loss. No need for models to tell us that.
  12. @ peacetracker
    "Currently, there are no objectively quantitative ice volume measurements with anthing remotely close to the necessary temporal and spatial coverages. Consequently, Morano and anyone else can only make objective observations about sea ice extent."
    That is simply untrue. It is widely known that multiple physical measurements of ice thickness are taken at regular intervals. These range from ice thickness measuring buoys to US Navy submarines to aerial ice thickness measuring instrumentation packages to ships measuring the thicknesses on their recon cruises to orbiting satellites (IceSat & CryoSat2). Anyone who would maintain otherwise is simply talking about things about which they know nothing...or simply lying with the intent to mislead. http://neven1.typepad.com/blog/2011/08/polarstern-reaches-north-pole.html http://neven1.typepad.com/blog/2011/09/more-on-ice-thickness-from-awi.html http://imb.crrel.usace.army.mil/ http://amap.no/swipa/ http://www.osi-saf.org/index.php PIOMAS is a useful tool to incorporate all of these metrics into a validated model using known ocean/atmospheric/ice dynamics to compare past observations to current ones: and
    Response: [JH] Perhaps this comment should be transformed into a rebuttal article?
  13. Peacetracker, if you want to find out the validity of someone's argument, ask them for evidence of their claims. Ask this WUWT joker for evidence of guesswork at PIOMAS. Essentially, the commenter is saying that PIOMAS scientists are faking each month's data point to make sure that volume is dropping like a rock. If you don't understand how sea ice volume is measured, then ask yourself what is the more likely claim: A) the dozens of scientists at several scientific organizations are knowingly committing fraud to make it look like sea ice volume is dropping. They come to work every day knowing that they're doing the exact opposite of what they're trained to do, the exact opposite of what they went through 6-10 years of college to do. B) sea ice volume is dropping, consistent with a warming ocean and atmosphere. Volume drop is also corroborated by evidence from people who live and work around the Arctic circle.
  14. @peacetracker #110: A recent example of direct measurement of central Arctic sea ice volume is described in detail in “Changes in Arctic Sea Ice: Young and thin instead of old and bulky.” To access this informative article, click here.
  15. peacetracker#110: "based upon sea ice extent and subjective guesses" Can anyone seriously contemplate circumstances in which areal extent is decreasing, but volume is increasing? That's patently ridiculous. See the Arctic ice threads.
  16. Very useful feedback. Thanks
  17. DSL, wow that IS a bit odd. Antarctic sea ice is expected to eventually start declining, but this seems more likely to be some sort of short-term fluctuation. The 'growth' in Antarctic sea ice has been small enough that the current year amount still drops below the long term average semi-regularly. This contrasts with the situation in the Arctic where skeptics got excited earlier this year about the extent coming CLOSE to the long term average for the first time in years. Make sure to read this: get far cry 3. Thus, the current dip is unusual, but not unprecedented. Looks like the Southern melt season started about two weeks early for some reason.
  18. Well, obviously, Antartica is losing ice due to the fact that our planet is warming up. Just because of the floods, dosent mean thats going to make it gain ice. And even if it gains ice, it will lose that ice anyway. Agreements?
  19. The date of the last update at the end of the article does not match the Update date.
    Response:

    [DB] The article update date is indicative of the last update/rewrite/iteration of the main article.  The date of the "update" below that indicates the date of the specific revision mentioned (correction of the incorrect quote).

  20. On the Antarctica ice melting issue aren't there some underwater active volcanos that would melt ice? Being there were crops and vineyards grown in Greenland between the 9th & 12th more or less how warm would temperatures have to get for that to happen again? What caused the temperatures to rise to that point before?
  21. muttkat, have a look at the Greenland used to be green myth. I doubt there would have been any vineyards there, though. As for underwater volcanoes, presumably they would be very noticeable, being as how the water temperature would get warmer the deeper you go towards those volcanoes ?
    Response:

    [DB] NSIDC has a FAQ on undersea volcanoes here:

    http://nsidc.org/asina/faq.html#volcanoes

    "The heat from the volcanoes would have dispersed over an enormous volume and had little effect on ocean temperature, much as a bucket of boiling water emptied into a lake would have little effect on the lake's temperature."

  22. #120 muttkat: There's no evidence for vineyards in Greenland in the MWP, temperatures were nowhere near warm enough for that! The only evidence for crops are a few grains of barley found in a Viking-age midden, but that does not confirm whether they were locally-grown or imported. Local growing of barley is maybe possible in the warmest years of the Greenland MWP, but the most sensible explanation is that the Norse Greenlanders imported it, due to a combination of low temperatures and poor soils. It would be a commodity worth trading for, as the Norse were partial to beer! There are a few active volcanoes in Antarctica, but not enough volcanism to do much damage to a whole ice sheet (ice sheet big, volcanoes small). Iceland is a good example, where Vatnajokull survives happily despite having several active volcanoes under it, notably Grimsvotn and Bardarbunga.
  23. Lifted from The Conversation: "A 364-metre-long ice core record has revealed an unusual pattern of rapid warming across the Antarctic Peninsula over the past 100 years. An Australian National University research expedition produced findings dating back 15,000 years, resulting in the first comprehensive temperature record of the Antarctic Peninsula. Dr Nerilie Abram said the Antarctic Peninsula is one of the fastest warming places on Earth and the findings will allow researchers to compare recent and past temperatures in the region for the first time." More here.
  24. Interested in your response to this post on WUWT. Thanks. http://wattsupwiththat.com/2012/09/10/icesat-data-shows-mass-gains-of-the-antarctic-ice-sheet-exceed-losses/#more-70757
    Response: [DB] It is customary when linking to an outside document to first provide your understanding of it. Please proceed to do so.
  25. OK. Watts is claiming that a recent report by NASA shows that satellite measurements find that the Antarctic as a whole is gaining land ice mass rather than losing it as previously thought. He also has a side-swipe at skeptical science suggesting you update this post and he provides a link to this page.

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