Slashdot Mirror
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 fact that this isn't an issue on geologic scales isn't what's concerning people. We're worried about whether or not this is something that will be a problem for the current and foreseeable human generations.
Sorry, but this is one of the most idiotic comments ever. Yes, this ice shelf has been stable/in equilibrium for 10,000 years, which admittedly, is drop in the bucket of our full Earth history. But those measly 10,000 years include the entire time period during which modern humans shed their hunter-gatherer past, developed farming and became more sedentary, organized higher-level civilizations and social constructs, etc. Yeah, the Holocene has been relatively stable climate-wise, and indeed, it's relatively stability has been indicated as one of the factors that permitted many of the technological and social innovations mentioned above. So now that the climate system is showing signs of instability, and going out of kilter, that doesn't worry you???
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.
It is really more a case of, "Do nothing because our profit margins are set for the current situation and we do not want to incur any additional costs by recognizing risks that upset our current plan".
Wherever You Go, There You Are
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.
Waterfox - a Firefox fork with legacy extension support, security updates and better privacy by default.
that's an awful long post.
too bad its all bullshit.
such a waste of time and effort.
-no one is asking to give politicians "unlimited power to regulate every aspect of your life"
-lots of people, far smarter than you, have already investigated, tested, and evaluated all the various natural process candidates.
-no one is saying we need to get below 100ppm CO2
-you ask for scientific evidence, when there are already tens of thousands of scientific reports and papers and findings already published.
-actually all of the observations DO support the theory. in fact they are the basis of it.
-actually all of the satellite data DOES support it.
-funny you mention the "adjustments". all the adjustments made actually lower the amount of apparent warming. it's not adjusted to match the theory, its adjusted to account for changes in instruments over the years, or location, or other factors. yeah, that's right. without the adjustments, the apparent amount of warming would be 20% higher.. this may be a shock to you, but a thermometer int he sun will read a higher temperature than one in the shade just a few inches away. so that way all the data is on the same baseline.
-nope, the models havent failed.
seriously, just fuck off.
your tropes are so tired and out of date, its getting boring repeatedly rebutting them every day.
you are the equivalent of a drunk in a bar questioning Einstein. Or more accurately, several thousand Einsteins.
(and seriously, who modded that bullshit insightful?)
The guy who said the election was rigged won the presidency with the second-most votes.
Hi, geologist here.
Your understanding is wrong. Or at least you misinterpret it.
We are indeed in an interglacial period, but were at the end of one before we fucked it all up. The warming period you expect happened 20-14 thousand years ago, and stabilized to what was the current climate between 10 and 6 thousand years ago. Indeed the stability of the climate over the last 10k years is widely credited with providing the right conditions for the development of agriculture and thus civilization. Those days are now done, what comes next is uncharted territory.
But the relevant laws of chemistry and physics are indisputable, known since Fourier's time in the early 1800s, and immune to PR and politics. The fine details of second order and tertiary feedback effects will only ever tweak the result, those won't and can't overcome the basic fundamental gross effect dictated by physics.
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