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Larson B Ice Shelf In Antarctica To Disintegrate Within 5 Years
BarbaraHudson writes: A new study (abstract) from NASA scientists predicts an Antarctic ice shelf half the size of Rhode Island will disintegrate around 2020. The shelf has existed for roughly 10,000 years. "Ice shelves are the gatekeepers for glaciers flowing from Antarctica toward the ocean. Without them, glacial ice enters the ocean faster and accelerates the pace of global sea level rise." At its thickest point, the ice shelf remnant is a half kilometer tall, and spans approximately 1,600 square kilometers. "The glaciers' thicknesses and flow speeds changed only slightly in the first couple of years following the 2002 collapse, leading researchers to assume they remained stable. The new study revealed, however, that Leppard and Flask glaciers have thinned by 65-72 feet (20-22 meters) and accelerated considerably in the intervening years. The fastest-moving part of Flask Glacier had accelerated 36 percent by 2012 to a flow speed of 2,300 feet (700 meters) a year."
The last 12,000 years has been an interglacial period. Melting is normal. It is better than freezing.
On what precedent do you base that?
I recall NASA predicting complete loss of arctic sea ice by 2013, and the navy predicting the same in 2016.
The first didn't happen, not even close, and the second doesn't seem likely to happen.
It's like listening to the news about the doomsday clock; it just gets old after a while, and I don't give a damn what supposed bright minds are behind it.
Rhode Island is supposed to be an island. The rising sea levels are only helping it to achieve its natural state!
Probably not enough rise to make that happen.
Although it is believed that the melting of floating ice shelves will not raise sea levels, technically, there is a small effect because sea water is ~2.6% more dense than fresh water combined with the fact that ice shelves are overwhelmingly "fresh" (having virtually no salinity); this causes the volume of the sea water needed to displace a floating ice shelf to be slightly less than the volume of the fresh water contained in the floating ice. Therefore, when a mass of floating ice melts, sea levels will increase; however, this effect is small enough that if all extant sea ice and floating ice shelves were to melt, the corresponding sea level rise is estimated to be ~4 cm.
However, if and when these ice shelves melt sufficiently, they no longer impede glacier flow off the continent, so that glacier flow would accelerate. This new source of ice volume would flow down from above sea level, thus resulting in its total mass contributing to sea rise.
My understanding is that we are in an Interglacial Period and we would expect things to warm naturally. At the current rate of melt (159 GT/year) Antarctica will take around a quarter of a million years to melt down (given its ice mass of approx 26400000 GT). From the historical perspective this seems to be a particualrly SLOW rate of natural melting.
Over the past few millenia we've seen the Roman Warm Period, Medieval Warm Period, and Little Ice Age. We are now recovering from the Little Ice Age which is why temperatures have been steadily increasing since the end of the 18th Century. Many AGW proponents (eg. Michael Mann) don't seem to want to know about the Little Ice Age nor that we would expect to see warming from natural climatic variability after it ended, exactly as we do see.
As far as I can tell these are all NATURAL processes. The AGW global warming skeptics are not denying that the world is warming, because it clearly has been since the Little Ice Age. All they are saying is that human CO2 emission is not the PRIMARY cause. This makes sense once one understands that CO2 has a diminishing non-linear effect on longwave radiation re-emission. The 'Greenhouse Effect' is essential for life, but most of the effect of CO2 occurs below 100 ppm and the effect starts dropping off after that. Note that below 150 ppm plants (and thus, complex life) cannot survive. As CO2 increases there is a positive effect on plant growth - and when the World was at 5000 ppm (we're around 400 ppm today) not only did life exist, it thrived.
But even if AGW were true, how would giving politicians complete power to regulate every aspect of your life, and to take all the income from your hard work and redistribute as they saw fit have any impact on the climate on a global scale? it just doesn't make sense if you think about it for more than a millisecond.
No time at all, all you have to do is provide the scientific evidence for this. At the moment the AGW proponents have to talk about "consensus" because the actual observational data does not support the AGW hypothesis at all. In fact, the true 'deniers' are the AGW proponents, who refuse to accept that the data does not support their hypothesis and a new hypothesis must be generated - in accordance with the Scientific Method.
Does it not seem strange that the satellite data (which is not 'adjusted' to match the theory like the increasingly estimate surface coverage data is) does not support AGW and yet the media narrative is relentless that AGW is 'settled science'. The problem is not whether AGW is true or not (on evidence, the theory seems set to be falsified at this stage), but that the media has a narrative which refuses objective reporting of the counter-evidence. This should trouble everyone who seeks to perform honest science. There is also the problem that all the predictions are based on computer models whose prior predictions have utterly failed to match observations
For those interested in the physics from a guy who literally wrote the (advanced, graduate-level) textbook on atmospheric dynamics you may wish to see Dr Murray Salby's explanation of where the climate models are wrong (warning: you need reasonably advanced mathematics/physics to follow the lecture - so only fellow science Jedi need watch):
https://www.youtube.com/watch?... [67 mins]
Based on the observational evidence and the historical record, it seems the only sane position to take at this moment is skepticism of the AGW theory. No one is denying the scientific effect of atmospheric CO2, or that the Earth is warming - what is under debate is the balance between natural climatic variation and human CO2 emission (vs the massive CO2 emission from the microbial biosphere, for example) and debate about the limits of predictive accuracy of computer models of a very complex and chaotic system.
Saying that it formed during the current interglacial is misleading. This is an ice shelf, and ice shelves are the result of glaciers moving into the ocean and not breaking off. So it probably formed because the glaciers started moving a bit more rapidly, and it also probably had ice at the oceanwards side that broke off and melted, and which may well have been older.
FWIW, glaciers are always moving, but as the start to melt their motion speeds up. For a glacier to grow it needs to be accumulating new ice faster than it looses it through moving into an area where the ice is removed faster than its formed. This was said in a sort of general way, because some glaciers live high in the mountains, and when they descend they drop chunks of ice down hill. In the case of an ice shelf, the glaciers are pushing out onto the ocean and floating, so the weight of the terminus is suspended. This "ice shelf" creates back pressure that tends to hold the glacier in place, but the glacier is also pressing the ice shelf to move further out to sea, where it becomes unstable.
I think we've pushed this "anyone can grow up to be president" thing too far.
File:Arctic-death-spiral.png
Not hard to say at all, it's clear where that spiral is heading. Zero Ice at the north pole.
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You 'recall' a lot of bullshit. Unsourced bullshit.
But, BTW, the arctic sea ice is decreasing by about 12% per decade.
http://www.wunderground.com/cl...
Nothing to worry about, right? Not even close to worrying?
There are two types of people in the world: Those who crave closure
OP:
I recall NASA predicting complete loss of arctic sea ice by 2013, and the navy predicting the same in 2016.
You:
after reviewing his own new data, NASA climate scientist Jay Zwally said: "At this rate, the Arctic Ocean could be nearly ice-free at the end of summer by 2012, much faster than previous predictions."
US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections.
Are you unable to see the difference?
One NASA climate scientist said "the Arctic Ocean could be nearly ice-free at the end of summer by 2012", not "NASA predicted complete loss of arctic sea ice by 2013".
As it happened we hit the lowest sea ice extent since 1979 in September 2012.
A US Navy scientist predicted that "the Arctic could lose its summer sea ice cover as early as 2016", not "the Navy predicted complete loss of arctic sea ice by 2016".
As it happens we're currently only just inside 2 std deviations of the average, looking much like 2014 and 2013.
Anyway, to see what's happening go here http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/.
Watch this Heartland Institute video