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."
Rhode Island is supposed to be an island. The rising sea levels are only helping it to achieve its natural state!
Gee, it's a good thing Anthropogenic Global Warming is just a Big Leftist Conspiracy, or imagine how bad things would be!
How much evidence is required before denialist clowns will be convinced that Global Warming is a thing, and it is almost certainly Our Fault? It's kind of amusing that the same people that will shovel 100's of $B and sacrifice thousands of lives to counter theoretical threats posed by countries all over the world somehow require absolute irrefutable "I must personally get burnt before I'll ever admit fire exists" proof when it comes to climate change?
One must note that the ice sheet has **ONLY** existed for 10,000 years.
It's very important to stress this point, as those who do not understand geologic time are at risk of thinking that 10,000 years is a long time.
It's a nanosecond on the geologic clock.
This is a very young icesheet. It's loss is noteworthy, but does not have significance when viewed on macro timeframes.
------ The best brain training is now totally free : )
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.
If everything DOESN'T go to hell in 5 years, will the AGW people shut the fuck up? No, I didn't think so.
Peace is easy to achieve, just surrender. Liberty is much harder get/keep.
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
Are you really criticizing that scientists failed to accurately predict the demise of a 10,000 year old structure to a better precision than ~10 years? You're really that cynical over a change of like 0.1%? If I predicted that apple stock would double in a 2 year span, and in fact it only went up 99.9%, would you really not listen to my next stock prediction?
The age of the structure is irrelevant to the precision of when it will disappear. If they say it will disappear in 5 years, but it really takes 15, it's not inaccurate by .1% because the structure is 10,000 years old. It's inaccurate by 300%, because their 5 year prediction took 15 years to come true. Considering how many of these "sky is falling" predictions have been made over the past few decades, virtually none of which are even close to accurate when the end date of the prediction comes along, I'd say being cynical is quite appropriate.
"City hall" in German is "Rathaus" Kinda explains a few things......
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.
While I'm sure there are nut cases who have no idea of the reality that things just can't change that fast without huge hardship, there is also the old negotiation tactics, ask for 50MPG for all cars and maybe get 30MPG, then ask for 60 and maybe get 35. This has been working, car mileage has improved quite a bit in recent years.
Unluckily due to the nature of CO2 and its emitters, we're not going to get much more then a slowdown in the release of CO2, we're just too dependent on fossil fuels so really we should be planning on changes, many of which won't be for the better, at least short term.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
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
"They spike up very quickly after the ice age ends, drop back down, and generally fluctuate a significant amount without any human input at all.
Not according to any the historical temperature graphs [wikipedia.org] that I've seen. The temperature rises rapidly at the end of the ice age and then levels off an eventually begins to fall again.
http://en.wikipedia.org/wiki/H... [wikipedia.org]
The graph in the page you linked to shows temperature doing exactly what I claimed it does."
Acually it does not. The spikes you talk about are changes of about 0.3 degrees Celsius during hundred of years. Check the diagram more closely and you will also see that. The last "downspike" is what's called the little ice age and is still just about a dip which is about half a degree during a couple of hundred of years.
Never before in history has the temperature changed with more then 1 degree over 100 years. Even the during the sharp raise in the beginning in the diagram was that the case.
Natural variation in temperature are very slow and does not change as fast as today. The variations in temperature we see today are unprecedented for the last 10 000 years. Thats why scientist are saying its AGW. We, humankind has caused it.
Just saying it like it are.
I don't decide that the science must be wrong.
Gravity's pull on objects is settled science. Things really do fall down when you let them go. I do not therefore go and think that there's no such thing as gravity.
CO2 is a greenhouse gas. Settled science.
CO2 increases are from humans. Settled science.
Most or more than all (it would normally be continuing the cooling trend if not for us) of the recent warming is settled science.
How much, precisely? Not settled.
None or less than none? Settled. Both are bollocks.
Is it the Sun? Settled science. It's us. The sun is cooling
Is it cosmic rays? Not settled, 100%, but nearly so: every test so far shows no.
Gravity? Settled.
What causes gravity? Still debating, not settled.
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