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.
Well one shouldn’t need to point out that the Antarctic Peninsular is OUTSIDE the Antarctic circle; so the sun shines there EVERY DAY.
One also shouldn’t need to point out that the Antarctic Peninsula, has the entire Pacific Ocean on the West side of it, and the entire Atlantic Ocean on the East side of, and those oceans slosh back and forth, in what are known as TIDES, on average, about twice EVERY day.
TIDES are typically characterized (on average) by the RISING and FALLING of SEA LEVELS, and since ice floats on sea water, this twice daily lifting and dropping of those ice shelves, will (on average) result in severe stretching stresses on both the top and bottom surfaces of those ice shelves. Try doing that twice a day to your favorite concrete road bridge and see what happens over time.
There are OTHER satellite pictures, that show sections of those sheleves that collapsed around 50 years ago, and have now grown back, but at a lower altitude, since they are lacking 50 years of snow deposition, that the surrounding areas have received.
So the breaking of floating ice shelves, that are in sunshine every day, and stressed daily is not a mystery.
And it also should not be necessary to point out that when you break ANY solid into two parts, the total surface area increases ALWAYS, no matter what, so the melting rate will increase, if in a melting regime, and subsequent breakup of melting pieces, will only accelerate the further melting rate due to the continual increase in surface area.
This phenomenon can be observed daily in any ordinary glass of ice washed in a small amount of Coca Cola (or Pepsi too).
Larry Ledwick (hotrod ) says:
April 5, 2012 at 4:48 pm
…
Yet if you look for “largest iceberg ever recorded” on wikipedia you will see no mention of this gargantuan ice berg,
—
actually the 1956 iceberg *is* mentioned as the largest in the Wikipedia article https://en.wikipedia.org/wiki/Iceberg
Richard M says: (April 6, 2012 at 9:01 am)
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.
Who are you kidding? We agreed that 30 year was the minimum or meaningful trendlines. But for your information, since the 60’s there is *no* 15 year period to be found without a positive trend line. Where is the graph to back up your claim?
Never mind, I am done here.
What’s that you have there? Oh, only some of the most advanced sophisticated human technology used to build and put it into orbit hard ware to observe the known universe, cool what are you going to use it for? (Waite for it) to watch ice melt! enough said!
What’s that you have there? Oh, only some of the most advanced sophisticated human technology used to build and to put it into orbit, hardware to observe the known universe, cool what are you going to use it for? (Waite for it) to watch ice melt! enough said!
@Hugh Pepper
Since your canary has passed in his cage did you engage in a full root cause analysis? Did your analysis conclude that it was CO2 that killed your canary?
I would also like to know how you prepare your chicken bones (since your canary is dead and all) do you boil them first?
How long do you dry them before you can employ them for their predictive powers?
The reason I ask is because I am interested in preparing my own chicken bones for their incredible predictive powers.
ROFLMAO HUGH, good one eh?
If I had to guess the engineers that helped design the ENVISAT instruments read this article and have to quietly roll their eyes. What ridiculous unscientific drivel.
Volcanism probably has no effect in that region of the Antarctic. Only CO2 does. There could definitely not be undiscovered undersea volcanoes and volcanic vents. Impossible. It’s all about CO2. I doubt any other factors except CO2 are at play on the peninsula. (sarc)
http://wattsupwiththat.com/2008/01/22/surprise-theres-an-active-volcano-under-antarctic-ice/
Third time lucky 😉
What’s that you have there? Oh, only some of the most advanced sophisticated human technology ever employed by any known civilization (that has ever existed on earth) being currently implemented to build and deliver this technology into orbit, some of the most advanced hardware in existence to observe the known universe. Cool what are you going to use it for? (Waite for it) to watch ice melt! enough said!
Gail Combs suggested earthquakes/volcanoes as having possible involvement in the loss of the Larsen shelf. The idea is reasonable. Larsen B is at about -65.4:-60.4 Deception Island, ” an island in South Shetland off the Antarctic Peninsula, which has one of the safest harbours in Antarctica. The island is the caldera of an active volcano, which caused serious damage to the local scientific stations in 1967 and 1969.” (Wikipedia) is at -62.9:-60.6, so there is clearly tectonic activity close by. Global warming seems an unlikely hypothesis in an area that averages around -30 deg C and can reach above zero for a few weeks in mid-summer.
Peter Roessingh says:
http://wattsupwiththat.com/2012/04/05/more-crack-in-the-antarctic/#comment-947263
Henry@Peter
thx. But I was asking for the actual raw data displaying to me the actual temps. measured
(MINIMA, MEANS, MAXIMA)
Marinara says
http://wattsupwiththat.com/2012/04/05/more-crack-in-the-antarctic/#comment-947516
Henry says
That was funny. I doubt though if many here caught your point. The other good point here (I cannot remember now who made it) is that the weight of increasing ice in the antarctic could be a (good) cause for the cracks.
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Have blessed Easter You All
If you are interested in riddles take a good look at this:
http://www.shroud.com
http://earthquake.usgs.gov/earthquakes/eqarchives/year/2002/2002_data.php
DirkH says:
April 6, 2012 at 12:44 am
Greg House says:
April 5, 2012 at 10:19 pm
“Terry Oldberg says:
April 5, 2012 at 8:51 pm
Though the IPCC climate models are popularly taken to make forecasts, they make none of them. They make “projections” which, though often taken to be forecasts, are not
=======================================
Really? According to the WordWeb dictionary the first meaning of the word “projection” is (surprise!): “a prediction made by extrapolating from past observations”.
And of course those projections have always been sold to the press and politicians by “climate scientists” as “predictions.”
The IPCC is careful enough to include a section where they define what is a projection and what’s a prediction in their book, so you can’t blame them for using words as they define them. Sorry no link, it’s somewhere in the AR4.
Anyhow, their idea is that they can’t make a prediction because they can’t initialize a climate model with the exact state at a given time as that state is not known. But that’s just a thinly veiled disguise to escape the critizism of mathematically knowledgeable nitpickers who tend to say, you can’t make a prediction for 2100 because of the exponentially growing discrepancy between your model and reality. This criticism cannot be refuted, only evaded.
================
http://www.ipcc-data.org/ddc_definitions.html
Definition of Terms Used Within the DDC Pages
“Projection
The term “projection” is used in two senses in the climate change literature. In general usage, a projection can be regarded as any description of the future and the pathway leading to it. However, a more specific interpretation has been attached to the term “climate projection” by the IPCC when referring to model-derived estimates of future climate.
Forecast/Prediction
When a projection is branded “most likely” it becomes a forecast or prediction. A forecast is often obtained using deterministic models, possibly a set of these, outputs of which can enable some level of confidence to be attached to projections.”
http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch3s3-3-1.html
3.3.1 Climatic drivers Projections for the future
The following summary of future climate change is taken from the Working Group I Fourth Assessment Report (WGI AR4), Chapter 10 (Meehl et al., 2007). The most likely global average surface temperature increase by the 2020s is around 1°C relative to the pre-industrial period, based on all the IPCC Special Report on Emissions Scenarios (SRES; Naki?enovi? and Swart, 2000) scenarios. By the end of the 21st century, the most likely increases are 3 to 4°C for the A2 emissions scenario and around 2°C for B1 (Figure 10.8).
=========
My bold. The IPCC uses projection to mean prediction, regardless some apologists for their failures like to pretend otherwise. But the point is anyway, that they have have proclaimed their models’ predictions as being real science, and changed the direction of governments to the detriment of tax payers, businesses and development world-wide directly from this claim. Their accountability cannot be downplayed, that’s just disingenuous.
Myrrh:
Though the IPCC says that “when a projection is branded ‘most likely’ it becomes a forecast or prediction” this does not make it so. Regardless of whether a projection is branded “most likely” it does not have the earmarks of a forecast/prediction.
Yes it is in a different wikipedia article than the one I was referring to. I was specifically referring to:
https://en.wikipedia.org/wiki/Iceberg_B-15
Which was returned from a google search for “largest iceberg ever recorded”, and in its first sentence says”
“Iceberg B-15 is the world’s largest recorded iceberg. It measured around 295 km long and 37 km wide (183-23 mi), with a surface area of 11,000 km² (6,835 mi²) — larger than the island of Jamaica. The mass was estimated around three billion tonnes. After almost a decade, parts of B-15 still have not melted.[1]”
Just another example of the inconsistency and unreliability of Wikipedia for controversial subjects. If a student does a targeted search for the largest ice berg he/she will likely find the erroneous information in B-15, rather than drill down to the bottom of a generic page on icebergs.
Thanks for finding that, at least someone who updates wiki has a clue.
Larry
Peter Roessingh says:
April 6, 2012 at 5:18 am
The moderator does not like my source showing that a timeframe of at least 30 years is needed for meaningful trends in climate change.
I do not trust GISS, but see the graphs below showing two different 30 year periods from both GISS and HadCRUT3. On both sets, the slope for 1982 to the present is LOWER than the slope from 1974 to 2004.
http://www.woodfortrees.org/plot/gistemp/from:1970/plot/gistemp/from:1974/to:2004/trend/plot/gistemp/from:1982/trend/plot/hadcrut3gl/from:1970/plot/hadcrut3gl/from:1974/to:2004/trend/plot/hadcrut3gl/from:1982/trend
How do they support the original assertion that
Hugh Pepper says:
April 5, 2012 at 3:52 pm
Should this occur warming will accelerate even more rapidly than at present.
So while there IS warming over 30 years, there certainly is no acceleration in the warming based on the above graphs. And since there is no acceleration in the warming, it cannot accelerate even more rapidly.
By the way, do you not agree with Santer that only 17 years is needed to see a trend?
http://wattsupwiththat.com/2011/11/19/santers-17-years-needed-for-a-sign-of-climate-change-compared-against-the-ipcc-models/
It’s been hinted at here but not said- INCREASED ice formation causes shelf ice to break off, not warming. More ice forms, the ice flows under the increased weight, extends out into the ocean too far, and- breaks off due to mechanical stresses. As mentioned, ice has almost zero structural integrity.
Peter Roessingh says:
April 6, 2012 at 11:38 am
But for your information, since the 60′s there is *no* 15 year period to be found without a positive trend line.
For RSS, it is now flat for 15 years and 3 months, since December, 1996. (slope = -0.000234717 per year) See
http://www.woodfortrees.org/plot/rss/from:1994/plot/rss/from:1996.9/trend
This is getting very close to Santer’s 17 years.
Woke-up this morning sure that I would find at least some conjecture from Stephen Mosher or Hugh Pepper or any of the warmists/ warmistas to my question: how can global avge temperature ever decline once caught in GHG “runaway greenhouse” … without invoking physical mechanisms unrelated to GHGs?
It’s a simple question. The warmists must have considered it given the unambiguous geological record of CO2 and global avge temeprature trends…surely?
Peter Roessingh says:
April 6, 2012 at 11:38 am
Who are you kidding? We agreed that 30 year was the minimum or meaningful trendlines. But for your information, since the 60′s there is *no* 15 year period to be found without a positive trend line. Where is the graph to back up your claim?
No, we didn’t agree on anything. You made a blanket statement that was not correct. There is no right or wrong time-frame to look at data. You just need to understand how it affects certainty. That also includes periods over 30 years.
Also, I never said there was a 15 year period. I said any period that matched ENSO phases within the most recent 15 year period.
Based on your lack of reading comprehension, I’m not surprised you’re susceptible to propaganda.
“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 just read this in CNN and they have a completely different spin on the 2.5 C.
Note the difference!
“The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5 degrees Celsius (36.5 degrees Fahrenheit) over the last 50 years — a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves.”
See
http://www.cnn.com/2012/04/05/world/antarctica-ice-shelf/index.html?hpt=hp_bn2
I’ve just found a paper analysing temperature data at Faraday station, which is located at the same latitude as the Larsen C icesheet, although on the other side of the peninsula.
http://rspa.royalsocietypublishing.org/content/463/2077/241.full
Our analysis has shown that the increase in the minimum monthly temperatures is approximately 6.7°C over 53 years (1951–2003), whereas we did not find any significant change in the maximum temperature over the same period.
Two points about this.
At this location the average daily temperature never gets above 2C or 3C, which means night time temperatures will very rarely get above 0C. So the large increase in minimum temperatures will have minimal effect on temperatures over 0C and hence minimal effect on ice melt.
As I explained in an article that Bishop Hill was kind enough to publish on his blog, minimum temperatures usually occur in the early morning when incoming solar insolation exceeds outgoing longwave radiation. Australian temperatures recorded at fixed times clearly show that at least half of the increase in minimum temperatures was due to increased solar insolation from decreased clouds and particulate pollution.
IMO it’s highly likely that the increased melt of the Larsen iceshelf’s is caused by increased solar insolation, which can melt (sublimate) ice at far below 0C. And not cause by the increases in minimum temperatures. Although both have a common cause, decreased clouds.
This also explains the large discrepancy of rapidly increasing sea ice surrounding the Larson icesheets while the icesheets themselves are decreasing, as I noted above.
The ‘melt’ of the icesheets will be cumulative over many years. So a relatively small increase in summer melt from solar insoation will accumulate over decades. This is not the case with sea ice, almost all of which melts every year, So increased solar insolation may cause a decrease in the summer sea ice minimum, but this ice will rapidly reform once the brief summer passes and have no effect on ice extent for the rest of the year. Decreased clouds will, of course, cause lower temperatures at night and its night 80% of the time around around Antarctica. Explaining the rapid increase in sea ice.
Henry@Philip
I very much doubt the report you quoted. I think the guys who reported and measured were confused.
I have now analysed all the daily results coming from 19 weatherstations in the SH
and found the following averages:
Maxima rising at 0.44 degrees C per decade
Means rising at 0.06 degrees C per decade
Minima going down at -0.10 degrees per decade
In the light of my own results the reported result of 0.5 degrees C warming per decade seems highly improbable. He even admits that he could not find similar warming at other places in Antarctica which should have let the alarmbells go off that something was wrong with the data from Faraday/Navadsky but it seems he chose to ignore it.
In addition, the reported warming is not coming from earth itself, e.g. due to increased GHG or volcanic activity or increased vegetation. It is due to more intense sunshine and or less clouds and or less ozone.
HenryP,
Care to give a reference that goes into more detail, what stations, over what period?
Decreasing minimum temps is an unusual finding over a significant number of stations. The more usual finding is most warming is in winter minimum temps.
The decrease in cloudiness seems to be at lower levels which has a particularly large effect on solar insolation when the sun is near the horizon ( just after dawn at midlattitudes and most of the time at the latitude of the Antarctic Peninsula), but as there no systematic measures of cloud changes by altitude, its another aspect of the climate we know almost nothing about.
Philip says:
Care to give a reference that goes into more detail, what stations, over what period?
Decreasing minimum temps is an unusual finding over a significant number of stations. The more usual finding is most warming is in winter minimum temps.
Henry says
I look at all the data from 1973-1976 to 2011 depending on availability.
Twelve (SH) stations are reported here:
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
I must still add the results of 9 more SH stations to my tables as reported there.
And a further 9 more NH stations…..
However, I am thinking of cutting my tables not per month but to rather look at time periods,
i.e. last 10 years, last 20 years, last 30 years etc. or as per relevant sun cycles.
Warming in the NH is now almost identical for maxima, means and minima: 0.27 degrees C per decade, but I can still clearly see that a large portion of the warming from the SH is taken to the NH by currents and weather systems.
Overall, globally, the ratio Maxima-Means-Minima is now standing at 4 :2 :1
My point was that the paper you (they) are quoting is apparently only based on the reported results from one station – which is completely rediculous.
Your title brings to mind penguin drug rings. Send in the (v)ice squad!