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Saturday, May 24, 2014

Larry Hamlin blunders down under in Antarctica

Sou | 12:16 AM 3 Comments - leave a comment

The rapid increase in the loss of ice in West Antarctica is really eating the heart out of Anthony Watts and his band of science deniers at WUWT. After, what is it, five articles in as many days?  Now there's a sixth (archived here). A shouty rant by Larry Hamlin who is really, really scared by global warming, going by his two latest articles.

You may remember this one from yesterday, where poor Larry was so terrified of the risk of wildfires he could scarcely restrain himself. Well, today it's the ice that's got him quaking in his boots. He's let forth on an article by Damian Carrington in the UK Guardian, which reports on a new study showing that Antarctic ice is disappearing twice as fast as it was a few years ago. (Larry was so overcome by fear that he could only manage a broken link to the article).

This is a bit long, so if you're on the home page, click here to read more...



Seas are rising by magic at WUWT


Larry is a denier who can't do his sums. What he is getting upset about is that he reckons that those journalists have it all wrong. Once again, like in his last article, Larry blames the media not the science and once again he's wrong and the science reporters are right.  The nitty gritty of Larry's argument is that the "alarmist" journalists confused a doubling of sea level rise with a doubling of ice melt. Thing is, the sea level rise he refers to is from melting Antarctic ice. So if he used his noggin, Larry would have realised that if seas are rising twice as fast from melting Antarctic ice then that Antarctic ice must also be melting twice as fast.


Three papers, three different teams, similar results


This is the third paper about Antarctic ice loss that's been published this month. Firstly I wrote about an on the ground measurement of the retreat of glaciers flowing into the Amundsen Sea (Rignot14). Then there was the modelling exercise of the Thwaites and Haynes glaciers to estimate how long it will take them to melt (Joughin14)

This paper is by team of scientists led by Malcolm McMillan from the University of Leeds. From sciencedaily.com:
Three years of observations show that the Antarctic ice sheet is now losing 159 billion tonnes of ice each year -- twice as much as when it was last surveyed.
A team of scientists from the UK Centre for Polar Observation and Modelling, led by researchers at the University of Leeds, have produced the first complete assessment of Antarctic ice sheet elevation change.
They used measurements collected by the European Space Agency's CryoSat-2 satellite mission, which carries an altimeter specially designed for this task.
In sharp contrast to past altimeter missions, CryoSat-2 surveys virtually all the Antarctic continent, reaching to within 215 kilometres of the South Pole and leading to a fivefold increase in the sampling of coastal regions where today's ice losses are concentrated.
Overall, the pattern of imbalance continues to be dominated by glaciers thinning in the Amundsen Sea sector of West Antarctica. However, thanks to the improved capabilities of CryoSat-2, problem areas such as the rugged terrain of the Antarctic Peninsula can now also be surveyed.
On average West Antarctica lost 134 gigatonnes of ice, East Antarctica three gigatonnes, and the Antarctic Peninsula 23 gigatonnes in each year between 2010 and 2013 -- a total loss of 159 gigatonnes each year.

I wrote about ice loss in the Antarctic a few months ago.  A 2012 study by Sagsen et al estimated that from 2002 to 2011 there was a net loss of ice from the from the northern Antarctic Peninsula and the Amundsen Sea Sector amount to 151±9 Gt a year and a slightly positive mass balance, 19±16 Gt a year in East Antarctica. Including these and pluses and minuses from other areas, this 2012 study estimated a mass loss of 103 ± 23 Gt yr-1.


West Antarctic ice is increasing at a faster rate


This latest research reports an overall net loss of ice, including East Antarctica, totalling around 160 Gt a year between 2010 and 2013. From sciencedaily.com again:
In West Antarctica, ice thinning has been detected in areas that were poorly surveyed by past satellite altimeter missions.
These newly-mapped areas contribute additional losses that bring altimeter observations closer to estimates based on other approaches.
But the average rate of ice thinning in West Antarctica has also increased, and this sector is now losing almost one third (31%) as much ice each year than it did during the five year period (2005-2010) prior to CryoSat-2's launch.
Lead author Dr Malcolm McMillan from the University of Leeds said: "We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of between 4 and 8 metres per year near to the grounding lines of the Pine Island, Thwaites and Smith Glaciers."
The map below shows the Amundsen Sea and the location of Pine Island and Thwaites glaciers.

Credit: AntarcticGlaciers.org


Larry is scared of melting ice, and he should be worried


Here's part of what Larry is rabbiting on about (sorry, Eli):
The big scary headline claim in almost all of these alarmist articles which screamed that the rate of Antarctica ice loss has “doubled” compared to prior estimates is wrong. The alarmist reporters have managed to confuse two distinct issues addressed in this latest study which dealt with both continental Antarctic ice loss as well as the contribution of this Antarctica ice loss to sea level rise....
...The climate alarmist reporters misunderstood the total Antarctica ice loss picture from this latest study and provided incorrect information in their articles. They appear to have confused this latest studies reported sea level rise contribution estimate of 0.45 mm per year which is about “double” prior study estimates of 0.19 mm per year as being applied to ice loss values which is incorrect.

Umm, no Larry. The big scary headline was based on satellite estimates of changes in mass balance. The sea level rise is a consequence of that melting ice. Of course the sea will rise more quickly as the ice melt accelerates.  If the sea level rise from melting Antarctic ice has more than doubled, then the rate of ice melt must also have gone up by almost the same amount. It's basic arithmetic!


Different methods, similar results


Larry seems to think that the following contradicts the finding that the rate of ice loss has doubled in recent years. It doesn't.
This latest study (abstract link below) clearly establishes that the continental Antarctica ice loss estimates based on past satellite gravimetry surveys are “consistent” with the latest study radar altimetry total ice loss findings. 

Earlier studies were based on GRACE satellite gravimetry surveys. This latest report is based on Cryosat2 radar altimetry. As explained in ScienceDaily.com,
Launched in 2010, CryoSat carries a radar altimeter that can 'see' through clouds and in the dark, providing continuous measurements over areas like Antarctica that are prone to bad weather and long periods of darkness. The radar can measure the surface height variation of ice in fine detail, allowing scientists to record changes in its volume with unprecedented accuracy.

Larry quoted from the full paper, but misrepresents it. He seems to have got confused by the explanation that measurements by one means (gravimetry) are consistent with those of the other (radar altimetry).
At the continental scale, the most recent estimates of Antarctic ice sheet mass balance are based solely on satellite gravimetry surveys [Barletta and Bordoni, 2013; Velicogna and Wahr, 2013; Williams et al., 2014]. According to these studies, the rate of ice mass loss from Antarctica has increased progressively over the past decade and, between 2010 and 2012, fell in the approximate central range 105 to 130 Gt yr-1. Our survey puts the contemporary rate of Antarctic ice sheet mass loss at 159 ± 48 Gt yr-1, a value that, although larger, is nevertheless consistent given the spread of the gravimetry-based uncertainties (16 to 80 Gt yr-1). A possible explanation for the discrepancy is the exceptional snowfall event of 2009, which saw an additional ~200 Gt of mass deposited in East Antarctica [Boening et al., 2012; Lenaerts et al., 2013; Shepherd et al., 2012] that, although absent from the CryoSat-2 record, does factor in the gravimetry-based estimates of imbalance.

Larry thought (or said he thought) that it means that there hasn't been an acceleration in ice loss. But it doesn't. All it means is that the two different ways of measuring mass balance come up with results that are similar enough, given the error margins. What the scientists in this most recent paper are saying is that the estimates based on radar altimeters are consistent with those based on gravimetric surveys, given the error margins of both and allowing for the dump of snow in East Antarctica in 2009. Larry's quote also points out that "the rate of ice mass loss from Antarctica has increased progressively over the past decade". But Larry doesn't discuss that particular point. It would spoil his story.


Larry picks some cherries


Larry misrepresents another paper to support his false claim that the rate of sea level rise hasn't increased. It has. He cherry picks from the abstract, carefully omitting the sentences I've highlighted:
We use 1277 tide gauge records since 1807 to provide an improved global sea level reconstruction and analyse the evolution of sea level trend and acceleration. In particular we use new data from the polar regions and remote islands to improve data coverage and extend the reconstruction to 2009. There is a good agreement between the rate of sea level rise (3.2 ± 0.4 mm·yr−1) calculated from satellite altimetry and the rate of 3.1 ± 0.6 mm·yr−1 from tide gauge based reconstruction for the overlapping time period (1993–2009). The new reconstruction suggests a linear trend of 1.9 ± 0.3 mm·yr−1 during the 20th century, with 1.8 ± 0.5 mm·yr−1 since 1970.

Like a previous WUWT article about this paper, Larry misrepresents it. He wants to pretend it's still only 1.9 mm a year. He doesn't want WUWT readers to know that the current rate of sea level rise is now 3.2 mm a year! 


Don't worry, it's tiny as a fingernail


Larry also writes that:
The authors of this latest Antarctica ice loss study estimate that the rate of global sea level rise contributed by their measured Antarctica ice loss results is about 0.45 mm per year which is about the thickness of a human fingernail.
That's a variation of the denier meme, "it's too little to worry about". Yes, if seas were only going to rise by .45mm a year for the next 100 years, they'd only rise by 4.5 cm or less than two inches in a century. Thing is, the ice is going to continue to melt faster as time goes by. Every 360 Gt of ice adds around 1 mm to global sea level.  When West Antarctica melts away, seas will rise by around four metres. When just the Amundsen glaciers melt away seas will rise by more than a metre. And that may happen sooner rather than later. And we haven't even discussed what's happening in Greenland.

The ice most probably won't melt evenly either. It will most likely slip into the sea in sudden bursts. Joughin14 indicated that when the contribution to sea level rise hits one millimetre a year then all bets are off, and I quote: "we take 1 mm/year of sle to be a threshold that, once crossed, marks the onset of rapid (decades) collapse as the grounding line reaches the deepest regions of the marine basin." That could happen in 200 years, or less if the ice shelves totally collapse in the meantime.


Addendum - Richard Alley interviewed by Chris Mooney


There's a great podcast with Richard Alley here, where he discusses the collapse of WAIS with Chris Mooney - the interview with him starts at 16:09 (slide the slider). He's talking about how, as Antarctica melts, the sea level will rise a little more around the USA than the global average.


From the WUWT comments


omnologos finds Larry's prose turgid and complains:
May 23, 2014 at 2:16 am
Please somebody spare the readers and do some heavy sub-editing. The verbiage doesn’t bode well for the accuracy of the post. In other words, I stopped reading at the 20th latest and 50th studies.

Bloke down the pub is a fake sceptic who willingly embraces the notion that Lying Larry is right and the Guardian (and scientists) are wrong - as if! - and says (quoted text removed):
May 23, 2014 at 2:23 am
You give the Grauniad too much credit by suggesting that they are merely stupid, when in fact they are being outright mendacious.

Joel O'Bryan is another fake sceptic because he wants to believe what he reads at WUWT rather than real life observations and says:
May 23, 2014 at 2:32 am
Whatever the mass loss is from Antarctica today and tomorrow, it is nothing compared to 14 kyr to 8 kyr ago when the seas were rising at an astonishing ~10 cm/decade (1 meter/century, 10 meters/millenium). That’s climate change you can believe in.
Fortunately today and tomorrow, +19 mm/decade (1.9 mm/yr, 3/4″ per decade) delta MSL is something that can be mitigated without a crisis. That rate assumes the WAIS continues on its long predicted path to “collapse”. Collapse in this case is tne geologic term of millenia. 
Pointman is projecting when he says:
May 23, 2014 at 3:03 am
That “blunder” wasn’t a blunder. They just didn’t expect anyone to actually read and check the garbage driving the headlines.
Pointman
It's WUWT-ers like him who don't "actually read and check the garbage driving the headlines" at WUWT. In fact, no-one so far has bothered to check Lying Larry's garbage. George Lawson says:
May 23, 2014 at 3:11 am
I wonder how much of the MSM will have the courage to report on the error and retract the alarmist coverage which they were only too ready to push last week.

Okay, there's finally someone who questions the WUWT article. Nick Stokes says:
May 23, 2014 at 3:35 am
I’m not sure what the detailed basis of the claim is. But it was not invented by the Guardian. The press releases from ESA (European Space Agency) and Leeds University are here. Both begin:
“Three years of observations from ESA’s CryoSat satellite show that the Antarctic ice sheet is now losing 159 billion tonnes of ice each year – twice as much as when it was last surveyed.”
Georg decides to run some numbers that proves to him that "scientists don't know nuffin'". Of course he makes a false assumption that the current melt rate won't increase any further when he says:
May 23, 2014 at 3:55 am
Dear folks
I am just a guest and rarely come here to this site due to lack of time, but the notice made me check some facts:
160 billon tons = 160 gigatons = 160.000.000.000 tons.
Now that is more or less equivalent to 160 km3
160 km3 compared to 26 millon km3 total antarctic ice mass (wikipedia) is as much as 0,000615%. So in 100 years it would be 0,0615% of antarktic ice mass which has gone lost. And in 1000 years not eaven 1%. Awfully shocking really. The problem seems to be that not eaven scientists take one minute to think about what they asess. Journalist – ok – nobody expects that.
Please rectify me if I am wrong.
A thank you from Spain for your worthfully work.

carbon bigfoot doesn't care for facts and rudely expresses his or her humble opinion and says:
May 23, 2014 at 5:02 am
IMHO ice accumulation or depletion has nothing to do with sea levels. Tectonic plate movement has everything to do with measurable sea movement. Only engineers and geologists who work in the real world can appreciate the fact, while you scientists jerk off in immeasurable insignificant tiny mms!!

JohnWho is an "it's natural" believer and says:
May 23, 2014 at 5:57 am
Oceans rise. Ice melts.
Don’t see any sort of evidence that anything being done by humanity, especially the emission of CO2 into the atmosphere is the major, or even minor contributory, cause. 




Malcolm McMillan, Andrew Shepherd, Aud Sundal, Kate Briggs, Alan Muir, Andrew Ridout, Anna Hogg, Duncan Wingham. Increased ice losses from Antarctica detected by CryoSat-2. Geophysical Research Letters, 2014; DOI: 10.1002/2014GL060111

Joughin, Ian, Benjamin E. Smith, and Brooke Medley. "Marine Ice Sheet Collapse Potentially Under Way for the Thwaites Glacier Basin, West Antarctica." Science 344, no. 6185 (2014): 735-738. DOI: 10.1126/science.1249055

E. Rignot, J. Mouginot, M. Morlighem, H. Seroussi, B. Scheuchl. "Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011".. Geophysical Research Letters, 2014; DOI: 10.1002/2014GL060140

Jevrejeva, S., J. C. Moore, A. Grinsted, A. Matthews, and G. Spada. "Trends and acceleration in global and regional sea levels since 1807." Global and Planetary Change (2013).  http://kaares.ulapland.fi/home/hkunta/jmoore/pdfs/Jevrejevaetal2013GPChange.pdf

3 comments:

  1. Nitpicking:

    (1) 4.5 cm is "less than 2 inches", not "less than 1/2 inch".

    (2) The Abstract under "Larry picks some cherries" *is* poor. They cite the satellite-era (1993-2009) value of 3.2 mm/yr but then revert to tide gauges and cite 1.8 mm/yr , but that is for 1970 on. If you don't pick carefully through it, you'd think that there is no acceleration through the 20th century.

    Admittedly, the Abstract is scientifically correct, but authors of scientific papers should stillw rite so that the casual reader gets the right message.

    ReplyDelete
    Replies
    1. Oops - missed that one. Fixing now. Thanks PL.

      And WUWT will exploit anything they can in a scientific paper. It's not as if Larry could have missed it. He had to have deliberately cut the middle out of the abstract after he copied it, so no-one would see it.

      Delete
    2. My own error: I glossed over the fact that he'd *suppressed* the highlighted text! But he learned from Watts, Curry, Tol, ... that this was legit, so he can't be held responsible?

      Delete

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