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“Antarctica loses three trillion tonnes of ice in 25 years”–BBC

June 14, 2018
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By Paul Homewood

 

A really quite disgracefully misleading and emotive headline from the BBC:

 

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Antarctica is shedding ice at an accelerating rate.

Satellites monitoring the state of the White Continent indicate some 200 billion tonnes a year are now being lost to the ocean as a result of melting.

This is pushing up global sea levels by 0.6mm annually – a three-fold increase since 2012 when the last such assessment was undertaken.

Scientists report the new numbers in the journal Nature.

Governments will need to take account of the information and its accelerating trend as they plan future defences to protect low-lying coastal communities.

The researchers say the losses are occurring predominantly in the West of the continent, where warm waters are getting under and melting the fronts of glaciers that terminate in the ocean.

"We can’t say when it started – we didn’t collect measurements in the sea back then," explained Prof Andrew Shepherd, who leads the Ice sheet Mass Balance Inter-comparison Exercise (Imbie).

"But what we can say is that it’s too warm for Antarctica today. It’s about half a degree Celsius warmer than the continent can withstand and it’s melting about five metres of ice from its base each year, and that’s what’s triggering the sea-level contribution that we’re seeing," he told BBC News.

Space agencies have been flying satellites over Antarctica since the early 1990s. Europe, in particular, has an unbroken observation record going back to 1992.

These spacecraft can tell how much ice is present by measuring changes in the height of the ice sheet and the speed at which it moves towards the sea. Specific missions also have the ability to weigh the ice sheet by sensing changes in the pull of gravity as they pass overhead.

Imbie’s job has been to condense all this information into a single narrative that best describes what is happening on the White Continent.

Glaciologists usually talk of three distinct regions because they behave slightly differently from each other. In West Antarctica, which is dominated by those marine-terminating glaciers, the assessed losses have climbed from 53 billion to 159 billion tonnes per year over the full period from 1992 to 2017.

On the Antarctic Peninsula, the finger of land that points up to South America, the losses have risen from seven billion to 33 billion tonnes annually. This is largely, say scientists, because the floating ice platforms sitting in front of some glaciers have collapsed, allowing the ice behind to flow faster.

East Antarctica, the greater part of the continent, is the only region to have shown some growth. Much of this region essentially sits out of the ocean and collects its snows over time and is not subject to the same melting forces seen elsewhere. But the gains are likely quite small, running at about five billion tonnes per year.

And the Imbie team stresses that the growth cannot counterbalance what is happening in the West and on the Peninsula. Indeed, it is probable that an unusually big dump of snow in the East just before the last assessment in 2012 made Antarctica as a whole look less negative than the reality.

Globally, sea levels are rising by about 3mm a year. This figure is driven by several factors, including the expansion of the oceans as they warm. But what is clear from the latest Imbie assessment is that Antarctica is becoming a significant player.

"A three-fold increase now puts Antarctica in the frame as one of the largest contributors to sea-level rise," said Prof Shepherd, who is affiliated to Leeds University, UK.

"The last time we looked at the polar ice sheets, Greenland was the dominant contributor. That’s no longer the case."

In total, Antarctica has shed some 2.7 trillion tonnes of ice since 1992, corresponding to an increase in global sea level of more than 7.5mm.

The latest edition of the journal Nature has a number of studies looking at the state of the continent and how it might change in a warming world.

One of these papers, led by US and German scientists, examines the possible reaction of the bedrock as the great mass of ice above it thins. It should lift up – something scientists call isostatic readjustment.

New evidence suggests where this process has occurred in the past, it can actually constrain ice losses – as the land rises, it snags on the floating fronts of marine-terminating glaciers.

"It’s like applying the brakes on a bike," said Dr Pippa Whitehouse from Durham University. "Friction on the bottom of the ice, which was floating but has now grounded again, slows everything and changes the whole dynamic upstream. We do think the rebound (in the future) will be fast, but not fast enough to stop the retreat we’ve kicked off with today’s warming.

"Ocean warming is going to make the ice too thin for this process to help."

In Imbie’s last assessment, the contribution of Antarctica to global sea-levels was considered to be tracking at the lower end of the projections that computer simulations had made of the possible height of the oceans at the end of the century. The new assessment sees the contribution track the upper end of these projections.

"At the moment, we have projections going through to 2100, which is sort of on a lifetime of what we can envisage, and actually the sea-level rise we will see is 50/60cm," said Dr Whitehouse. "And that is not only going to impact people who live close to the coast, but actually when we have storms – the repeat time of major storms and flooding events is going to be exacerbated," she told BBC News.

https://www.bbc.co.uk/news/science-environment-44470208

 

Despite the apocalyptic headline, ice loss has only been contributing about 0.3mm a year to sea level rise, about an inch per century. Given that sea levels have been rising at around 8 inches a century since the 19thC, there is no evidence that this is not a long term phenomenon we are seeing.

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https://notalotofpeopleknowthat.wordpress.com/2018/05/20/woods-hole-climatologist-gives-false-evidence-to-congress/

 

Indeed as Shephard himself is forced to admit, we did not start collecting data until 1992. This sort of melting could have been going on for centuries or longer. In fact, another paper published this month by Kingslake et al finds that there has been  extensive retreat and re-advance of the West Antarctic Ice Sheet during the Holocene.

As Shephard also remarks, the melting in West Antarctica is due to the intrusion of warmer water, and therefore nothing at all to do with GHGs or “global warming”. It is highly unlikely that such changes in ocean currents have not happened many times before.

 

Then there is the question of the accuracy of measurements. A major study by NASA in 2015 discovered that Antarctic ice mass has actually been increasing since 1992, basically because of greater snowfall, and not decreasing as this new study claims.

In reality, measurements of ice mass are not exact and are subject to huge margins of error.

But anybody reading the BBC’s headline would be entitled to think we’re all going to drown soon!

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42 Comments
  1. Philip Hurst permalink
    June 14, 2018 11:42 am

    There is an equally alarmist story on the same topic in today’s “New York Times”. Odd coincidence?

  2. Joseph Sharp permalink
    June 14, 2018 11:49 am

    I thought there was volcanic activity beneath West Antarctica.

    • June 14, 2018 12:12 pm

      Yes indeed Joseph. There is a lot going on beneath Antarctica, particularly in the western regions and little is known about it. There is an active rift running from mount Erebus through to Desolation Island and It is interesting to note that the article indicates that the warming is in fact coming from below with warmer water rather than by radiation.

      Also, although a Trillion sounds a very large number, it is probably not very significant in the whole context of the totals and the history involved.

      Be that as it may the Warmunist Meme will continue to insist that we indulge in our fears and panics.

      • Paddy permalink
        June 15, 2018 6:44 am

        The water at Deception Island is so warm, due to volcanic
        activity, that you can actually bathe there.

    • June 14, 2018 12:19 pm

      Absolutely. There are active volcanoes under the west part of Antarctica. I have an article from “Science Daily” dated January 22, 2008: “First Evidence of Under-Ice Volcanic Eruption in Antarctica.” The lead author, Hugh Corr, is from the British Antarctic Survey. According to the headlines, it erupted in 325 BC and remains active.

      • BLACK PEARL permalink
        June 14, 2018 3:12 pm

        As usual in BBC climate related reporting, the truth is ALWAYS the first causality

    • Ardy permalink
      June 15, 2018 12:19 am

      I read that there is also a lake of water under the ice due to volcanic activity.

      There was an article about 6 months ago on huge ice loss at Antartica at the ‘union of concerned scientists’ and I questioned what work was done to eliminate the effects of volcanic activity. No reply.

  3. Joe Public permalink
    June 14, 2018 11:54 am

    It seems Amos is suffering selective amnesia.

    Just 7 months ag he repoerted:

    “Antarctica’s warm underbelly revealed”

    “The East is a giant chunk of old, cold continental crust. The West, however, underwent recent rifting in the Cretaceous (100 million years ago) that has pulled it apart.

    “This rifting has thinned the crust and brought hot material from deep down in the Earth – from hundreds of km down – to within 100km or so, or even maybe less, of the rock surface,” said co-author Tom Jordan.

    “It confirms what you would expect from the sparse, exposed geology in West Antarctica where we have volcanoes.”

    https://www.bbc.co.uk/news/science-environment-41972297

    Even back then, the Graun reported:

    “Scientists discover 91 volcanoes below Antarctic ice sheet.

    Scientists have uncovered the largest volcanic region on Earth – two kilometres below the surface of the vast ice sheet that covers west Antarctica.”

    https://www.theguardian.com/world/2017/aug/12/scientists-discover-91-volcanos-antarctica

  4. It doesn't add up... permalink
    June 14, 2018 12:02 pm

    From the abstract https://www.nature.com/articles/s41586-018-0179-y

    it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation).

    So on a more normal reckoning, we would use 2 standard deviation (1.96 if you really believe it is normally distributed), to get 2,720+/- 2,780 billion tonnes and 7.6+/-7.8mm. In other words, they are not reasonably certain that there has been any net ice loss at all, since we can’t reject that at the 5% significance level.

    More fake science, misreported as the authors knew it would be when they opted for 1 s.d. error data. Indeed, the figures look to be suspiciously concocted already – they obviously strained every sinew to try to justify a 2 s.d. conclusion, but in the end couldn’t quite manage it without completely destroying their credibility.

    • It doesn't add up... permalink
      June 14, 2018 6:28 pm

      Do you have a problem with this comment?

    • Ardy permalink
      June 15, 2018 12:25 am

      I also wonder why, if the ice is melting underneath, it would be calving? I read that calving is due to the pressure of increased snow and ice.

  5. June 14, 2018 12:19 pm

    3000 Gt / 362 Gt/mm = 8.3 mm. 🤣

  6. Scott Scarborough permalink
    June 14, 2018 12:34 pm

    This study does not contradict the 2015 NASA study that concluded that Antarctica is gaining ice. This study is about the WESTERN Antarctic ice sheet (you know, the place with all the underwater volcanos). The 2015 NASA study was about TOTAL Antarctic ice. When people try to pull the wool over your eyes you have to listen very carefully to what they are saying.

  7. Richard Bell permalink
    June 14, 2018 1:25 pm

    This article was shown on the BBC News on PBS in the USA last night ……. and as you correctly say it was made out / edited to sound like we were all about to drown !!! …… The BBC used to be a wonderful organization when I was growing up ……. But now it is SO heavily leaning towards the left and the Green Blob……..Very sad !!!

    • dave permalink
      June 14, 2018 1:44 pm

      So many memes…so many cracked records on autoplay…

      It reminds me of the joke about the man who goes to prison with lifers. On the first evening, there is a gathering in the common room. A prisoner gets up and says “One thousand and three!” and everybody laughs. The new man asks his companion why. He replies that everybody has heard all the jokes so often that they only need to to refer to them by their numbers. The next evening the new man feels emboldened to get up and tell a joke: “One thousand and three!” Dead silence. He sits down and looks at his companion in a questioning way who informs him “You didn’t tell it right!”

  8. Broadlands permalink
    June 14, 2018 1:46 pm

    Yet another scary story with no follow up or discussion on what anyone could possibly do about it, even if it is true. Act now… To do what?

    • dave permalink
      June 14, 2018 3:24 pm

      “…no follow up…”

      I would like a precise calculation of how much land is irrevocably lost under water, for each 0.7 mm of “sea rise,” per member of the human race. And how that compares to the loss of land per capita that is entailed by the present burgeoning world population. This latter loss is easily calculated. There are now about 15,000 square meters per person. The number was 50,000 when I was born! Already, 35,000 has been filched from me. And my patrimony continues to shrink by 300 per year.

  9. Athelstan permalink
    June 14, 2018 1:46 pm

    am ****ed if I am going to pay $200 to read this guff.

    The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise. Here we combine satellite observations of its changing volume, flow and gravitational attraction with modelling of its surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation). Over this period, ocean-driven melting has caused rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. We find large variations in and among model estimates of surface mass balance and glacial isostatic adjustment for East Antarctica, with its average rate of mass gain over the period 1992–2017 (5 ± 46 billion tonnes per year) being the least certain.

    guesstimated since 1992? How, what is the baseline calculated, are remote sensing estimates, quantification like for like?

    It’s wishful thinking and hypothesized, supposition done by computer modelled junk reading from a dodgy hand picked baseline (Pinatubo filled the upper SH with particulates and aerosols – went up in 91) and anyway even if these ‘think of a figure’ are even 5% ± of the truth, FFS the Anarctic Ice sheet isn’t going to disappear anytime SOON.

    Good grief, talk about clutching at non existent straws, this is just more alarmunist death rattles

    What we know, away from the western shelf: the Antarctic ice sheet is STILL accreting.

    • dave permalink
      June 14, 2018 3:27 pm

      “…errors are one [sic] standard deviation…”

      They should be two. But this would put zero into the frame as a possible number, and they would not like that, would they?

      • Athelstan permalink
        June 14, 2018 5:11 pm

        not like it one bit.

      • It doesn't add up... permalink
        June 14, 2018 6:51 pm

        I pointed that out in a comment that has yet to appear.

  10. June 14, 2018 1:55 pm

    Ice could be melting there for a lot of reasons including geothermal heat and volcanic activity. If the proposition is that we must cut fossil fuel emissions to moderate sea level rise, it must be shown that the rate of SLR is responsive to the rate of emissions.
    https://ssrn.com/abstract=3023248

  11. keith permalink
    June 14, 2018 2:36 pm

    Yes, just another biased fake news story from the kings of Fake News, the BBC.

  12. June 14, 2018 3:57 pm

    The sun warms the oceans, the oceans melt the ice. If it weren’t for the sun, we would all be buried in ice. Of course the Government will now waste even more £billions of our (taxpayers) money on preventing sea level rise due to “climate change” from devastating our coastal communities.

  13. June 14, 2018 4:06 pm

    David Middleton has it that 3 trillion tonnes is 99.989% of the Antarctic ice sheet, which rounds up to 100%.
    https://wattsupwiththat.com/2018/06/14/good-news-99-989-of-the-antarctic-ice-sheet-didnt-melt/

    • dave permalink
      June 15, 2018 10:34 am

      I am sure you mean that 3 trillion tonnes is (100-99.989)% = 0.011% of the Antarctic ice sheet!

      “Over the last 25 years.”

      It is odd how statistical “news” is always presented in a manner which obscures how little of it is actually new. Thus the BBC will say “Last month the annual rate of inflation rose to 2.3%” when the ACTUAL information is that last month the index rose by, say, 0.2% The REST of “the annual rate of inflation” has taken place during the preceding eleven months, and already has been announced.

      When you check the stock market at noon today, you presumably know, and have mentally discounted, everything it did up to this morning’s opening. Any “shock” to your mental equiiibrium should solely be based on the change since you last looked.

  14. June 14, 2018 5:08 pm

    I have looked at the article by Imbie et al https://doi.org/10.1038/s41586-018-0179-y, and am surprised that, given the strong difference of opinion between this and a 2015 NASA study, (https://www.cambridge.org/core/journals/journal-of-glaciology/article/mass-gains-of-the-antarctic-ice-sheet-exceed-losses/983F196E23C3A6E7908E5FB32EB42268 ) there is little by way of proof that the Zwally 2015 paper is wrong when it claims that ‘ snow accumulation beginning 10,000 years ago currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers’, with a current rate of accumulation of ‘1.7cm/yr’; nor of the discussions between Zwally and Scambos (which I have not been able to access). Obviously I’m not in a position or even remotely qualified to know which is correct but, as a disinterested observer, I’m struck by this omission, and also by the huge difference in comparative volumes of EA, where the accumulation has been taking place (plus central WA), compared to the peripheral WA & the relatively tiny peninsula where most of the current loss is taking place. So at the moment, I’m not convinced that the NASA/Zwally position has been overturned and, given the seriousness of the new claim that Antarctica has taken over from Greenland as chief contributor to global sea level rise, when the Zwally paper claims the reverse, the differences should have been more explored?

  15. Joe Public permalink
    June 14, 2018 7:59 pm

    From Howard Goodall:

    ” … the uncertainty across all areas is stunning. It makes the final product almost useless. This is the result for the entire continent, with error bars”

    • It doesn't add up... permalink
      June 14, 2018 10:59 pm

      Those are the ONE standard deviation error bars. That is not the normal scientific criterion.

  16. Joe Public permalink
    June 14, 2018 8:07 pm

    Interesting thread by Stephen McIntyre, with comments from Paul Matthews & Howard Goodall

  17. David May permalink
    June 15, 2018 12:17 am

    I just can’t believe it until I see some real evidence. Either time lapse video or some kind of proof that I can see. I just think when the North Pole moves which is moving constantly then the ice will move or somewhere in that process there’s too many other conspiracy theories floating around for this to be 100 Proof

    • David May permalink
      June 15, 2018 12:28 am

      I just think climate is meant to change

  18. Coeur de Lion permalink
    June 15, 2018 6:19 am

    The BBC always lies

  19. Fudsdad permalink
    June 15, 2018 6:39 am

    I am surprised that there has been no mention of the BBC Inside Science broadcast yesterday on Antarctic ice which left the listener in no doubt that we are all doomed!!

  20. dave permalink
    June 15, 2018 10:38 am

    If only there were a way to “short” shares in the CAGW scam! Dodgy accounting is always an early harbinger of an enterprise going bust.

  21. June 15, 2018 5:27 pm

    The 7.6 mm figure seems to take into account losses by sublimation.

    However am I missing something or are they neglecting to account for the amount of water leaving the oceans to form the ice? From the published figures, if this is taken into account Antarctica only began contributing to sea level rise in 2017.

  22. June 15, 2018 11:23 pm

    Paul why do your say 3 mm rise, NOAA in their own site http://tidesandcurrents.noaa.gov/sltrends/sltrends.html state “The graphs give an indication of the differing rates of vertical land motion, given that the absolute global sea level rise is believed to be 1.7-1.8 millimeters/year”
    I believe tide gauges over algorithmic satellites anyday

    • dave permalink
      June 16, 2018 9:53 am

      “… 3 mm …”

      No, Paul said 0.3 mm a year.

      3 trillion tonnes of H2O transferred from the land to the sea, over 25 years, is equivalent to 120 cubic km of sea water being added each year to the basins. Divide this by the area of the oceans, which is 350 million sq km, and you get a notional increase of depth of 0.3 mm.

      Put another way: “They” have estimated that the total rise from this “source,” in the last 25 years, is – Wait for it! – one quarter of one inch.

    • June 16, 2018 9:53 am

      That’s what the BBC say

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