From the European Space Agency (ESA):
Satellite observes rapid ice shelf disintegration in Antarctic
5 April 2012
As ESA’s Envisat satellite marks ten years in orbit, it continues to observe the rapid retreat of one of Antarctica’s ice shelves due to climate warming.
One of the satellite’s first observations following its launch on 1 March 2002 was of break-up of a main section of the Larsen B ice shelf in Antarctica – when 3200 sq km of ice disintegrated within a few days due to mechanical instabilities of the ice masses triggered by climate warming.
Now, with ten years of observations using its Advanced Synthetic Aperture Radar (ASAR), Envisat has mapped an additional loss in Larsen B’s area of 1790 sq km over the past decade.
The Larsen Ice Shelf is a series of three shelves – A (the smallest), B and C (the largest) – that extend from north to south along the eastern side of the Antarctic Peninsula.
Larsen A disintegrated in January 1995. Larsen C so far has been stable in area, but satellite observations have shown thinning and an increasing duration of melt events in summer.
“Ice shelves are sensitive to atmospheric warming and to changes in ocean currents and temperatures,” said Prof. Helmut Rott from the University of Innsbruck.
“The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5°C over the last 50 years – a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves.”
Larsen B decreased in area from 11512 sq km in early January 1995 to 6664 sq km in February 2002 due to several calving events. The disintegration in March 2002 left behind only 3463 sq km. Today, Envisat shows that only 1670 sq km remain.
Envisat has already doubled its planned lifetime, but is scheduled to continue observations of Earth’s ice caps, land, oceans and atmosphere for at least another two years.
This ensures the continuity of crucial Earth-observation data until the next generation of satellites – the Sentinels – begin operations in 2013.
Credits: ESA
“Long-term systematic observations are of particular importance for understanding and modelling cryospheric processes in order to advance the predictive capabilities on the response of snow and ice to climate change,” said Prof. Rott.
“Climate models are predicting drastic warming for high latitudes. The Envisat observations of the Larsen Ice Shelf confirm the vulnerability of ice shelves to climatic warming and demonstrate the importance of ice shelves for the stability of glaciers upstream.
“These observations are very relevant for estimating the future behaviour of the much larger ice masses of West Antarctica if warming spreads further south.”
Radars on Earth observation satellites, such as Envisat’s ASAR, are particularly useful for monitoring polar regions because they can acquire images through clouds and darkness.
The Sentinel missions – being developed as part of Europe’s Global Monitoring for Environment and Security (GMES) programme – will continue the legacy of radar observations.
Hugh Pepper says:
April 5, 2012 at 3:52 pm
A very real danger is that the muskeg in the North will also melt releasing vast quantities of methane and CO2. Should this occur warming will accelerate even more rapidly than at present.
Muskeg is bogland in the tundra — it doesn’t melt, it thaws, and it does so every summer.
The only danger that thawed muskeg poses (other than falling into a hole and getting soaked) is that it provides a marvelous summer breeding ground for [channelling Carl Sagan] “billyons and billyons” of mosquitoes…
The British research station on the antarctic peninsula shows no rise of the temperature for the last 25 years.
Disko Troop says:
April 6, 2012 at 12:41 am
By the way, has anybody seen AlGore and the Hansen/Branson since they went to the Antarctic?
They’re collaborating on a Powerpoint presentation. The slides will dramatically depict the ravages of Glowbull Worming by showing that not a single polar bear remains in the Antarctic…
@Disko Troop says:
April 6, 2012 at 12:41 am
“Ice shelves break mechanically not by melting.”
Yup.
“By the way, has anybody seen AlGore and the Hansen/Branson since they went to the Antarctic? I have seen nothing about their triumphal return in the media, just a letter from the Hansen to Slovenia which could have been written by any 12 year old greenie activist. Are they still there, crow-barring bits off the ice shelf? Should we send a search party?
If they are still there, the last thing we should do is send a search party. Leave well enough alone.
@Werner Brozek
Please, adjust your time frame. Looking at climate change over a period of less than 30 years is really not meaningful.
See [SNIP: if you have an argument to make, make it here, but we are not sending traffic to an unreliable source. -REP] for a good illustration
On the far side of the continent the Amery Ice Shelf has been expanding for at least sixty years. I suppose you could use it as proof Global Cooling is occurring, and we are all going to freeze. However at some point it will break off, at which point we can use it as proof Global Warming is occurring, and we all are going to fry.
On the other hand, maybe we could just calm down. But would that get us grant money?
At last! So can we play golf any time soon now? Swedish news 2008; “Antarctica becoming a golf course”:
http://farm4.static.flickr.com/3276/2403752391_7202152bf3_o.jpg
Luther Wu says:
April 5, 2012 at 7:18 pm
What?
Only one troll?
I got a real laugh when I saw your comment came immediately after a comment from Lazy Teenager. And LT got something right for a change, he/she said he/she wasn’t a climate scientist! That has become obvious from the quality of the other comments he/she makes.
Steven Mosher said
@ur momisugly April 5, 2012 at 8:01 pm
“…Adding C02 or any GHG to the atmosphere raising the height at which the earth radiates that means, following known physical law, that the earth will cool less rapidly than it would otherwise…”
…………………………..
Steven, explain this to me if you will. How does raising the height at which the Earth radiates reduce cooling ?
I would have thought that if the effective radiating surface increased in height it’s radiating surface area would therefore have increased, which far from reducing the amount of cooling would in fact increase the amount of cooling thus providing a form of negative feedback.
In other words you would have us believe that a larger surface area radiates less heat away to space than a smaller surface area ?
Explain yourself please.
“The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5°C over the last 50 years – a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves.”
I find this statement untrue. I could not find anywhere such data confirming this trend in the SH>.
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
Note that the so-called ”global warming” is not global at all.
In the Southern Hemisphere (SH) there is almost no warming. Clearly, you can see a big difference in the results for means between NH and SH? Check out these two weatherstations’ results from the antarctic.
http://www.nerc-bas.ac.uk/icd/gjma/amundsen-scott.ann.trend.pdf
http://www.nerc-bas.ac.uk/public/icd/gjma/vostok.ann.trend.pdf
They are remarkably flat. Although I do not know where the original data are for these two graphs. Does anyone here know?
It’s remarkable how these people are able to state with such certainty that the warming is definitively anthropogenic in cause.
I always thought that temperatures needed to be above 0 Celcius for ice to melt. Silly me.
The moderator does not like my source showing that a timeframe of at least 30 years is needed for meaningful trends in climate change.
Here is the the example i wanted to give in the same format as the original poster provided his data.
http://www.woodfortrees.org/plot/gistemp/plot/gistemp/from:1880/to:1895/trend/plot/gistemp/from:1900/to:1918/trend/plot/gistemp/from:1914/to:1924/trend/plot/gistemp/from:1926/to:1934/trend/plot/gistemp/from:1936/to:1966/trend/plot/gistemp/from:1936/to:1966/trend/plot/gistemp/from:1961/to:1973/trend/plot/gistemp/from:1973/to:1979/trend/plot/gistemp/from:1978/to:1987/trend/plot/gistemp/from:1986/to:1995/trend/plot/gistemp/from:1986/to:1995/trend/plot/gistemp/from:1996/to:2001/trend/plot/gistemp/from:1997/to:2002/trend/plot/gistemp/from:2002/to:2012/trend
“As ESA’s Envisat satellite marks ten years in orbit, it continues to observe the…. drone, drone drone”
“One of the satellite’s first observations following its launch on 1 March 2002 was of break-up of a….drone, drone, drone”
How lovely. Ten years old and still singing like a Canary.
@Peter Plail
Added to a comment on a previous post was that Lazy Teenager is in Australia and runs a Mac software service for dental things.
Peter Roessingh,
How many of those short cooling periods were the result of cherry picking? You know, from an El Niño to a La Niña. Be honest now.
The fact is a good measure of climate change is likely to need over 100 years and probably more. Even 30 years is suspect. We know it has warmed since the LIA. We still don’t know all the causes of the first 250 years of that warming but you think you know the cause of the last 30 (-10 where no warming has occurred).
BTW, I got some prime ocean front property in Wyoming I can let go for a bargain.
Climate models set up scenarios then tell us what would happen under scenarios. The input info is part well-understood mechanics, part fudge factor, and part vast gaping holes of missing quantities of less well-understood mechanics. Given this foul-looking input soup, I would not be publishing papers based on the foul smelling wild-ass poop that comes out the other end. That such publishing happens (seemingly at break-neck speed these days) speaks loudly of budget constraints keeping scientists sitting at computer model terminals instead of being out engaged in expensive field research. Or they could just be lazy.
Mr. Hugh Pepper has ignited some colorful responses here. While I agree with the substance of the rebuttals, I want to say that flaming Mr Pepper is inappropriate. We skeptics hate it when it is done to us on other blogs. So let’s rise above, and concentrate on education.
It seems to me that cracking is also a mechanical issue. If a piece of ice is over an area that is not supporting it, (cantilever, simply supported), build up of more ice (weight) would eventually break the structure (crack). what’s the mechanical properties of ice, how many hollow areas or unsupoorted regions are there and then simple to calculate how much weight(load) to break it, might also help to explain the issue and also point out that it is the work of more cooling, rather than melting.
“What we see occurring at both Poles and in the Himalayas are changes equivalent to the “canary in the cage” phenomena.
That’s “canary in the coal mine”, Hugh. And…
Hugh could’nt bring himself to type the word “coal”………
@ur momisugly Richard M
Sure i picked those cooling periods (and it was not easy!). The whole point of the graph is that cherry picking allows you to suggest there is no warming signal! When Werner Brozek shows only 20 years of data and puts a a trendline on the last 10 years to suppport his claim there is no global warming he does just that.
We fully agree that 30 years is the minimum to make meaningful statements and show the significance of the trend.
By the way, I did not make any claims about the origin of the observed warming. I only commented on the misuse of statistics to show there was *no* warming.
@HenryP
The data you are looking for regarding the fast warming of the Antarctic Peninsula can be found in this paper:
Turner, J., Colwell, S., Marshall, G., Lachlan-Cope, T., Carleton, A., Jones, P., Lagun, V., Reid, P., Iagovkina, S. (2005). Antarctic climate change during the last 50 years. International Journal of Climatology, 25, 279-294.
http://onlinelibrary.wiley.com/doi/10.1002/joc.1130/pdf
It has an erratum. The correct figures are here:
http://onlinelibrary.wiley.com/doi/10.1002/joc.1212/pdf
As in poker, we see your satellite data and raise with other satellite data. From http://researchnews.osu.edu/archive/icetide.htm
They did it using the twin satellites of the Gravity Recovery and Climate Experiment (GRACE), a joint project of NASA and the German Aerospace Center. Large tides flow along the ocean floor beneath the Larsen and Filchner-Ronne Ice Shelves. Though scientists have long known of these tides, they have not yet been modeled accurately, said C.K. Shum, professor of geological sciences at Ohio State University. Yet the tides play a major role in scientists’ efforts to measure how much the ice sheets are melting or freezing, and how the melting ice will affect global sea levels.
While the tides cause only minute fluctuations in Earth’s overall gravity, they are actually composed of massive amounts of water, he explained.
The ice is a mile thick in parts, and the tides are so large that they can lift the shelves – with a combined area bigger than the state of California – as high as 15 feet.
Scientists believe that these unseen tides can carve into the ice from underneath and eventually cause pieces to break off, as part of the Larsen Ice Shelf broke off in 1995.
Looks mechanical and not CO2 to me.
sunspot says:
“when you look at the map you will notice that Antarctica appears to be the only country/continent on the planet with out an earthquake, ever?”
Something is clearly wrong. Antarctica has over 30 active volcanoes:
http://www.volcano.si.edu/world/region.cfm?rnum=19
http://www.volcano.si.edu/world/region.cfm?rnum=1900
Volcanoes always have associated earthquakes. I suspect there are few seismic stations in Antarctica (or perhaps none), which would explain the apparent absence of seismic activity.
Peter Roessingh says:
April 6, 2012 at 7:45 am
Sure i picked those cooling periods (and it was not easy!). The whole point of the graph is that cherry picking allows you to suggest there is no warming signal!
If you look at the any period over the last 15 years that is apples-apples (that is, ENSO consistent), you will see flat temperatures. Therefore, by making sure not to cherry pick the period you get no warming. That’s how one applies logic to the problem. You don’t have to do this kind of exercise with blinders on. The net is there has been no warming while CO2 emissions continue to increase.
The only way this could happen is for there to be a cooling mechanism that is masking the warming. Interestingly, the IPCC could not find anything that allows for this to happen. That leaves you with a bit of a problem. Either the IPCC is wrong … or … the IPCC is wrong.
Hugh Pepper says:
A very real danger is that the muskeg in the North will also melt releasing vast quantities of methane…warming will accelerate even more rapidly…
Hugh, you’re a genius! Because methane is reportedly 20X as potent a green house gas as CO2, it is imperative that we harvest as much as possible from Arctic regions before it gets released. Then we can convert it to far less dangerous CO2.
Of course, the resulting CO2 will start melting deadly methane hydrate deposits located worldwide:
http://commons.wikimedia.org/wiki/File:Methane_Clathrate_Location_Map_USGS.gif
So the obvious solution is to harvest them and convert them to CO2 as well. Hugh, you just solved the methane crisis and the energy crisis simultaneously, and made the world a more productive and beautiful planet to boot! I nominate Hugh Pepper for the next Nobel Peace Prize!
Does this need a (sarc) tag?