Are Antarctic Ice Shelves Really Shrinking?
By Paul Homewood
h/t NZ Robin
http://www.sciencemag.org/content/348/6232/327.abstract
According to a newly released paper, the floating ice shelves around Antarctica are melting at an ever increasing rate. According to the Editor’s Summary “If warming continues to cause ice shelves to thin, as they have for the past couple of decades, their disappearance may allow land-based ice to collapse and melt.”
I don’t know what warming they might be talking about, since atmospheric temperatures over Antarctica have barely changed since 1979. According to UAH, the trend is a statistically insignificant 0.02C/decade.
http://vortex.nsstc.uah.edu/data/msu/v6.0beta/tlt/uahncdc_lt_6.0beta1.txt
We also know that sea surface temperatures have been plunging in the last decade.
Even if we only look at summer temperatures, when logically most of the ice melt would occur, there is very little trend. Six of the last summers have actually been below average.
The only notable summer was 2012/13, when December and January were 1.29 and 1.27C warmer than average. Although unusually warm, such weather was not unprecedented in summer, as December 1989 was 1.36C warmer than average.
Finally, it is worth looking at the changes in sea ice concentration between 1980 and now. There has been a very noticeable increase in concentration all around the continent, hardly suggestive of thinner ice.
ftp://sidads.colorado.edu//DATASETS/NOAA/G02135/Apr/S_201504_conc.png
I simply do not believe that we have the accuracy of measurements, particularly back in the 1990’s, to come to any statistically significant conclusions about sea ice volumes over such a short period of time.
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
It seems odd to me that they can claim that thinning ice sheets will hold back less land ice yet those very same sea ice sheets are easily blown around by the wind. There is something bogus about their position, rather like the claim that melting land ice, in sub zero temperatures mind you, is resulting in lower salinity in seawater leading to easier ice sheet formation.
I mean, come on chaps you can do better than this nonsense surely.
About the only melting going on there is from the Undersea Volcanoes and the fact that it is a volcanically active area.
And those anomalies above 0º, what do they mean exactly? Are they really above the freezing point, that is, above 0ºC?
No, they’re anomalies against the 1981-2010 baseline
And, by the way, I took the liberty to use your article “Antarctic Sea Ice Expands To New Record In April” as a source to this:
http://elatrildelorador.blogspot.com.es/2015/05/antartida-record-de-extension-de-hielo.html
with due links to your original, of course. Hope you do not complain.
Any particular reason you don’t trust the data in the 90s? I had a colleague working on ERS-1 (which the publication uses, along with ERS-2 and finally ENVISAT) and he seemed always to rave on about how surprisingly well it all worked ..
Also, the article speaks of submarine temperatures rather than SST, so I’m not sure how that is particularly relevant.
Quite a good article, though, cheers for the find.
Wrong way round!
When the AMO is in warm phase, it warms up the atmosphere, not the other way around.
Using gravity to measure ice volumes has been notably unreliable–all sorts of calibration problems and no ground truth confirmation. The older measurements will be even less relaible.
As for submarine temperatures, if these are warmer then it cannot be due to GHG, as the energy involved is far too tiny to make any measurable effect on ocean temps on these timescales. Volcanoes are the most likely culprit.
The first sentance of the abstract is just wrong. Floating ice shelves retard very little, other than contributing mass that to be moved. It is the grounded portions of the,ice shelves that retards ice sheet seaward creep. ANDRILL showed that grounded Ross has not retreated in 4000 years. The 2014 SLR rise Thwaites paper (models mostly) was all about grounded retreat.
Thanks for this. Have you a comment on the BBC’s current broadcasts on Arctic warming, please?
Simon Chalton
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Just done!
“I don’t know what warming they might be talking about..”
Does anyone have access to the full article? They might explain there, quoting whatever data source they used. If they didn’t, as usual: it’s not even science for them to make such a statement.
It’s behind a paywall. Dave.
Just a little perspective —
Given that Antarctica is the highest, driest, coldest, windiest and brightest of the seven continents. It is roughly the size of the United States and Mexico combined and is almost completely covered by a layer of ice that averages more than one mile in thickness, but is nearly three miles thick in places. This ice accumulated over millions of years through snowfall. Presently, the Antarctic ice sheet contains 90% of the ice on Earth. The total surface area is about 14.2 million sq km (about 5.5 million sq mls) in summer, much larger then the continental United States, approximately twice the size of Australia, and fifty times the size of the UK.
Add to that the sea-ice surrounding this massive continent and we have a truly incredible amount of ice.
So, this possible retreat amounts to what?
At best just a little wiggle on the timeline.
Hopefully the authors of this paper will be on the next expeditionary trip to Antarctica to see firsthand how all that ice is retreating.
Just saw some guy on ABC News24 this morning – was not concentrating initially but presume he was a “climate scientist” – in a small boat a few 100 meters off shore from an ice shelf smugly stating – you guessed it – “not only is the Antarctic getting warmer, it is happening faster than we originally thought!”. This was not a statement about loss from the West Antarctic shelf or a specific glacier but – as recorded in the segment – the whole of the continent, apparently. Where do these people get their data from? Why doesn’t the media check their sources? I need to get over it……..
The data if thinning Antarctic ice shelf is consistent with the work of Eric Rignot at UC-Irvine. He claims warmer water circulating under the ice shelf is causing the Ground Line, where the support of the ice by land is receding. He also reports that from sonar and radar measurements through the ice, the find the ice thickness decreasing in the Western Antarctic. First, is there agreement on this data?
If so, with no warming air and sea surface temps cooling, what could be causing the land ice loss? Ice loss in Antarctica could be very serious. Is there some muti-decadanal circulation bringing warmer water to Antarctica?