Antarctica's Ice Mass: Is it really losing ice, gaining ice, or both?

That is the relevant question, when you read alarmist stories about ice melt in Antarctica. On March 25th, for example, the BBC dutifully reported “Antarctic Shelf Hangs by a Thread” in a report by science correspondant Helen Briggs. Here is the tag line below the title: “A chunk of ice the size of the Isle of Man has started to break away from Antarctica in what scientists say is further evidence of a warming climate.” A few paragraphs below that another tag line, also in boldface type, reads “Unprecedented Warming.” Similar alarming snippets characterize the entire report.

What this report doesn’t make terribly clear, however, is the fact that this breakup is in the Antarctic Peninsula, a finger of land that stretches for several hundred miles into the South Atlantic. There is evidence the ocean in this region is somewhat warmer in recent years – true enough – but this fact is dwarfed by the mounting evidence the overall ice mass of Antarctica is increasing.

Will the Cedar Waxwing summer northwards or southwards?

Here are the comparisons – the Isle of Man is 227 miles in area – which means that if this ice shelf were a mile think (and it isn’t), it would have a volume of 227 cubic miles. Antarctica, by contrast, has an area of 5.0 million square miles.

More recently, on April 15th, the BBC ran another story entitled “Forecast for Big Sea Level Rise.” The story referenced a study by “a UK/Finnish team” – we couldn’t find the actual study online – that concluded “Sea levels could rise by up to one-and-a-half metres by the end of this century, according to a new scientific analysis… substantially more than the Intergovernmental Panel on Climate Change (IPCC) forecast in last year’s landmark assessment.”

Other news sources offered similar stories – alarming headlines with a shallow exploration of the underlying facts: Reuters “World sea levels seen rising 1.5m by 2100,” New Scientist “Sea levels ‘will rise 1.5 metres by 2100′,” The Tech Herald “Report says sea level rise worse than feared,” and so on.

Accompanying the BBC story was a photo of a young woman and her infant child standing waist deep in water. But was there any further explanation of how the study reached it’s findings? According to one of the study’s authors, Svetlana Jevrejeva from the Proudman Oceanographic Laboratory (POL), near Liverpool, UK, “…by the end of the century, we predict it will rise by between 0.8m and 1.5m,” and “The rapid rise in the coming years is associated with the rapid melting of ice sheets.”

Ok, rapid melting of ice sheets is the cause. And the data? Here is all the article offered us in that regard: “The latest satellite data indicates that the Greenland and West Antarctic ice sheets are losing mass, though the much bigger East Antarctic sheet may be gaining mass.”

If you wade through this material, what comes out is the following: If temperatures increase sufficiently in the polar regions, “melt water” on the surface of land based ice sheets may drain into fissures in the ice, undermining the stability of the ice and possibly causing it to slide into the ocean at a rate far faster than if it were to simply melt from the outside inwards. Fair enough. So is Antarctica warming up?

We contacted Dr. Roger Pielke Sr., a renowned climatologist with a nuanced position on global warming – he believes, as we do, that the role of CO2 in driving climate change is grossly overstated, and the role of land use changes is grossly understated. His online blog Climate Science is an excellent source of informed and balanced data on global climate trends. Here is the gist of his findings, filed online on April 7th in a post entitled “Recent Data on Surface Snowmelt in Antarctica:”

“In the March 25 2008 issue of EOS, there was a News item by Marco Tedesco titled “Updated 2008 Surface snowmelt Trends in Antarctica” (subscribers only). It reports the following:

Surface snowmelt in Antarctica in 2008, as derived from spaceborne passive microwave observations at 19.35 gigahertz, was 40% below the average of the period 1987–2007. The melting index (MI, a measure of where melting occurred and for how long) in 2008 was the second-smallest value in the 1987–2008 period, with 3,465,625 square kilometers times days (km2 × days) against the average value of 8,407,531 km2 × days (Figure 1a). Melt extent (ME, the extent of the area subject to melting) in 2008 set a new minimum with 297,500 square kilometers, against an average value of approximately 861,812 square kilometers.”

This evidence suggests that Antarctica, where 90% of the land based ice in the world resides, is increasing in mass. And this fact is ignored or downplayed in virtually every mainstream report available today, and indeed the mainstream press continues to infer that Antarctica is melting at an alarming rate. But on balance, the ice mass in Antarctica is not melting, it is probably getting bigger.

As Pielke wrote me earlier this week, “My views have not changed… I agree that the alarmist view being widely disseminated is not supported by the science.”

16 Responses to “Antarctica's Ice Mass: Is it really losing ice, gaining ice, or both?”
  1. NeilT says:

    Ah yes that old chestnut.

    If you take a Look at the overheads, you can see that up to 1/3 of the Wilkins shelf is breaking up. But only this one chunk has, so far, fallen off. But let’s not worry about that reality.

    As for the Ice mass balance in Antarctica? Well of course we can use the passive microwave data in exculsion. But if we use the GRACE satellites which record the gravity changes of ice loss and gain, we see that around 150 billion tonnes of Ice is being lost in total off the entire continent of Antarctica every year.

    And of course we can use the politically sanitised IPCC4 estimate to dismiss need for change over sea level rise can’t we? The IPCC4 estimate is under the assumption that we implement Every Recommendation in the report and then we will ONLY see a 1M sea level rise over the next decade. The current rise is 4.5 to 5mm per year. Which means 0.4 to 0.5 by the end of the century. Looks good so far?

    But of course that’s not the whole story as usual. Because the recorded sea level rise per year in 2004 was 3mm. So if we carry on with this increase in sea level rise, then we get to 2 or 3 meters rise by the end of the century.

    And that is not accounting for any of the accelerants on the way.

    The scientists are being quite reserved IMO

  2. NeilT says:

    Sorry not next decade, next century.

  3. RalfT says:

    Talking about the water rising validates the concern and yes the continual concern man has had since finding the ocean. Our Earth is constantly changing is many aspects. Mostly in ways we can’t control. The best thing we can do is build sand castles and rebuild them when the sea takes them.

  4. Ed Ring says:

    NeilT: Your comments are interesting. I’ve forwarded your comment regarding the GRACE satellites to Dr. Pielke and I would welcome him or anyone to respond. In one area however I am qualified to make a point – you state “around 150 billion tonnes of ice is being lost in total off the entire continent of Antarctica every year” and I can tell you with confidence that is an extremely insignificant amount of ice. 150 billion tons (metric) is equal to 150 gigatons, or 150 cubic kilometers. Antarctica has 20 MILLION cubic kilometers of land based ice. So the figure of 150 billion tons sounds like a lot, but in context, it represents a negligible percentage of the total Antarctic ice mass, and negligible sea level rise.

  5. Ed: Thanks for sending! With respect to the GRACE data, this is what NASA reports in 2006 [see here]. They state “The researchers found Antarctica’s ice sheet decreased by 152 (plus or minus 80) cubic kilometers of ice annually between April 2002 and August 2005.”

    That is about how much water the United States consumes in three months (a cubic kilometer is one trillion liters; approximately 264 billion gallons of water). This represents a change of about 0.4 millimeters (.016 inches) per year to global sea level rise. Most of the mass loss came from the West Antarctic ice sheet.”

    Since GRACE has only been available since 2002, it is a short record so we do not know if this is a long term trend or not. It would be useful to see an update of this data since 2006.

    The snow melt information I reported on my weblog shows that with respect to surface melt, however, it actually has been decreasing over time [see here]. This leads one to suspect that the loss of Antarctic ice may be due to undercutting by water below the edges of the ice, and not surface loss. It is still a climate issue but surface melting does not appear to be the reason for the loss of mass seen by GRACE.

    Moreover, the Antarctic sea ice area extent remains well above average [see here] and, at the very least, news articles should include this observation [incidentally the Arctic sea ice extent is well above last year at present; see here].

    I have no idea if these trends will continue but the correspondents have been selective in the data they present. For a complete picture, we need all of the relevant observational (not future model prediction) information presented.

    I hope this helps. Please let me know if you need further feedback.

    Best Regards, Roger Pielke Sr.

  6. FredT34 says:

    I’m sorry, but I can’t see any relation between EOS news you report and your next sentence “Antarctica, where 90% of the land based ice in the world resides, is increasing in mass.”

    I just can read that “Surface snowmelt was 40% below the average of the period 1987–2007. The melting index in 2008 was the second-smallest value in the 1987–2008 period. Melt extent in 2008 set a new minimum with 297,500 square kilometers, against an average value of approximately 861,812 square kilometers.”

    This only means that snowmelt was lesser than previous years – not that it was negative: melt concerned “only” 300.000 square km, which is not exactly nothing.

  7. Ed Ring says:

    FredT34: Let’s say it appears the overall ice mass is probably increasing in Antarctica – I have added the qualifier “probably.” The point of this post is that the fact all this is highly debateable is rarely clear if all you read is mainstream press reports. Let’s reiterate:

    The GRACE data suggesting a net loss of 150 km3 over a three year period through August 2005 is not significant, given the ice mass of Antarctica is probably somewhere around 20 million km3 – do you have access to any data on this? The notion that 300,000 km2 of seasonal surface ice melt is not a significant amount holds up by at least three relevant comparisons – the average melt historically is nearly triple that amount, 861,812 km2, and Antarctica itself has a surface area of 13.2 million km2, and finally (ref. Pielke above), the Antarctic sea ice extent at present is well above where it was at this time last year.

    As for undercutting by warm currents – recent data from Aquabuoys (5,000 of them were launched only in 2002, with the ability to dive and surface automatically, releasing ocean temperature data at various depths) suggests the ocean, overall, is cooling.

    Our point isn’t that we shouldn’t be concerned about climate change. We only advocate the debate as to the extent and severity, as well as the causes, remain open.

  8. Al Fin says:

    I am very concerned about climate change. I am afraid that we are entering a new, cooler regime of climate where crops will fail due to a much shorter growing season.

    If only we could have warmer weather instead of cooler! Then perhaps we could grow two crop cycles a year, instead of less than one! Instead of starving in the cold, we can thrive in the warm. If only.

  9. Serge says:

    Video about researches on mentioned above subjects:

    Antarctic Ice Sheet Losing Mass, According To CU-Boulder Study (March 2, 2006)
    (data from Gravity Recovery and Climate Experiment, or GRACE)

    Global Warming May Cause Increased Antarctic Sea Ice (2005)

    More links can be found in video description.

  10. Pete says:


    I’m afraid you’re missing ‘unanticipated consequence’ while you’re arguing the ‘trivial millimeter’.

    The West Antarctic Ice Shelf is sliding down an inclined plane similar to a boat ramp. Like all boat ramps, as the tide comes in, the boats or ice shelf in this case, rises and therefore slides faster and more easily.

    But this is inconsequential: the ‘boat ramp’ is running perpendicular to seven giant glaciers. They are moving at varying speeds. Some of them are being affected by the melt water that’s now running under them as much as 2 meters deep. (Caltech) Some of them are being affected by the ground tempeature rise caused by the increasing activity of the ring of northwest volcanos. Some, but not all, are moving at speeds that vary across the glacier to the extent that the glacier is being pulled apart. But still, thats not the major process.

    If the Ice Shelf begins to move at a rate that no longer allows it to function as a plug for the vast glaciers of the central highlands, the ice mass moving to the sea will no longer be measured in cubic kilometers nor even tens of cubic kilometers. It will be, rather, a moving portion of the 8 million square kilometers, 15,000 meters thick.

  11. Pete says:

    Check that:

    13,829,430 km2
    15,918 FEET…..not meters, FEET.
    i studied math at JPL….

  12. Ed Ring says:

    The discussion on Antarctica’s ice mass could go on and on. It appears settled the amount of “loss” is below the noise level. It isn’t easy to find information on the total land-based ice mass on Antarctica, but if we accept the claim that sea levels would rise 61 meters if 100% of it melted, we can impute the mass. There are 335 million square kilometers of ocean on the planet, so you can easily calculate the ice mass of Antarctica must be about 20.5 million gigatons. A net loss of 150 gigatons against a mass of 20.5 million gigatons is nothing. It is beyond the rounding error – certainly beyond the capability of the Grace satellites to accurately record.

    Digging deeper, it appears generally acknowledged that the sea around most of Antarctica is cooling, and the surface temperatures in Antarctica are cooling. The one anecdote that remains somewhat alarming has nothing at all to do with climate change – it appears some instability may be imparted to the ice mass through vulcanism. Perhaps we should look into all of this further, but at this point there doesn’t appear to be anything behind claims of global warming causing alarming melt trends in Antarctica.

  13. Pete says:

    The discussion on Antarctica could go on and on, but it won’t. The question of diminished world ice mass or increased mass has been answered: glaciers have disappeared and are disappearing all over the world. To discuss the Antarctic melt in terms of the mass of the Antarctic is not the point: the speed of the melt- what is the annual percentage increase- is what is being determined.

    The loss of the ice shelf in its entirety is only important to the animals and plants that live in under it. It’s a question of time. As well, we have no idea of the multitude of possible interactions. It’s the finger we are looking for: the direction shown by the pointing finger.

  14. just wandering says:

    i am not a scientist or scholar or anything like that just an ordinary person who has a question. I was wandering about the potential growth of new life that will occur when or if the ice melts and the land warms. what do any of you presume will happen. I think that with all of the talk of global warming there may be some good come of it by way of new growth. We need green plants to produce oxygen for us right? so could this happen on the “caps” ? and if it does what kind of plants do you think might grow there, tropical or grass lands? please dont’ think i am stupid i was just curious.

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