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Ward Hunt Ice Shelf Breaks In Two
heidi writes "CNN has this story on the breakup of the largest ice cap. A permanent feature for the previous 3,000 years, it has broken into two pieces. "The Ward Hunt Ice Shelf, on the north coast of Ellesmere Island in Canada's Nunavut territory, broke into two main parts, themselves cut through with fissures. A freshwater lake drained into the sea, the researchers reported.""
Psst... there are no penquins in the arctic.
RTFA, in particular the following two passages:
Local warming of the climate is to blame, they said -- adding that they did not have the evidence needed to link the melting ice to the steady, planet-wide climate change known as global warming.
"There's a regional trend in warming that cycles back 150 years," Mueller said in a telephone interview. "I am not comfortable linking it to global warming. It is difficult to tease out what is due to global warming and what is due to regional warming."
The Arctic region is warming far faster than the rest of the world (I seem to recall estimates of five times faster), if the rest of the world is indeed warming at all, and its related to natural shifts in water and wind currents. Even if the world temperature was stagnant, this area would still likely be warming, and the shelf would have cracked anyway.
You can never go home again... but I guess you can shop there.
On the geological timescale, 3000 years of solid Ward Hunt Ice Shelf is really just a little blip. For all the worries about human greenhouse gases, we should probably also take a serious look at natural cycles. Only 12,000 years ago, you could walk out to the Farallon Islands outside SF.
Leads? There's a word for the actual cracking and fracturing process "calving", but I think that only applies to glaciers and icebergs.
YLFI
One god, one market, one truth, one consumer.
According to the article, Derek Mueller of Laval University said "It is difficult to tease out what is due to global warming and what is due to regional warming." He didn't call global warming a "myth." He accepted global warming as fact and only said that there was impossible to say whether it, or regional warming, was the cause of this particular event.
Here's an excerpt from the EPA's web site:If the EPA web site under Bush/Cheney (who are pawns of the oil industry) acknowledges global warming as fact, that should give you head-in-the-sand types a clue. Wouldn't it be terrible if we reduced pollution and it didn't fix global warming? Oh the horror!
No, but I do have a PhD in modelling glacial systems during the last Ice Age, so I'll give it a go (appolgies for only using examples from the gulf stream in the N.E.Atlantic, that's the region that I know).
There is a potential risk to the warm surface currents from the loss of floating ice, though it isn't to do with a one-off influx of fresh water. This will rapidly disperse over the ocean and make no perceptable difference.
However, the 'pump' driving the global conveyer is the constant differential melting and freezing at the base of the sea ice. Sea ice is essentially floating fresh water. If you freeze part of sea water into fresh water you are left with dense, cold, salty water. This sinks to the bottom, and then flows south from the arctic. Warm, surface water then flows north to replace it, forming the Gulf Stream (and other similar currents around the world).
Over the last few decades the extent of sea ice in the Arctic has shrunk noticably. There must be a point at which this will have an effect on these currents[1].
It is not clear what the level of sea-ice required to maintain the currents is, nor on quite how the currents will respond (gradually decreasing or simply shutting down). However there is evidence from the sedimentary record of the last interglacial that the gulf stream in the North East Antlantic, at least, switched on and off a number of times, and that the switch from 'on' to 'off' was very rapid.
There is thus the possibility that current climate trends will result in a situation in which the flow of warm water to the N.E.Atlantic may cease (or dramatically reduce) over a timespan of years or decades, producing dramatic climate changes in north Western Europe (especially Iceland and North Norway, but Britain, Ireland and France are also major beneficaries of the Gulf Stream). The lack of transfer of heat from the warmer regions may also result in higher sea-surface temperatures in those regions, which in turn could provide more energy for severe bad weather and hurricanes. There are futher possible effects from the lack of the cold water current. These are important in carrying oxygen around the oceans, and when they upwell against continental shelves they bring nutrients from the deep ocean to the surface, producing rich fishing grounds.
[1] It is also, incidentally, having a major effect on polar bears, which rely on sea ice in their hunting.
I'm giving up on debating global warming on Slashdot, it seems just about everyone is convinced its bunk. With the weather getting more and more extreme, could you at least understand why we are worried?
Well, I just wanted to make everyone aware of the new distributed project - www.climateprediction.net.
Whether you agree with the theory of human caused global warming or not, with this you can help getting the world scientific community more accurate climate models.
Unfortunately only a Windows client available at the moment, but a Linux one is in development. Personally I think this project and the
Folding at Home distributed project are much more deserving of peoples' clock cycles than Seti or distributed.net.
Cheers,
Lars
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You, sir, are so wrong it hurts my eyes to read!
Place a big chunk of ice in a container and fill it with water. Then sit back and see how the melting of ice does not rise the water level. Then get back to your physics books and figure out why it doesn't.
The problem with global warming is not with floating ice. It's with Antarctica where ice is sitting on the continent. Melting of that ice will rise the sea levels.
That's false even by the scientists' own admission. The models are not predictive. Part of the obvious falsity of the claims made by the IPC is that the computer models project warming at the surface, and in the upper atmosphere. The upper atmosphere has actually cooled. If the model is not predictive - it is worthless. The models can not even manage predictiveness for known past climate events.
Reality check:
I can't seem to find direct figures on CO2 release from Krakatoa. However, we can do a ballpark estimate. Various sources state that it ejected 5 cubic miles of material. Other sources indicate that magma saturated with volatile compounds holds up to 6% compressed gasses, most of it water. Let's assume that Krakatoa's magma was 2% CO2. So that's 2% of 5*1609^3 = 416 million cubic meters of CO2. At 1070 kg/m^3 (liquid phase), that's 445 megatons of CO2.
Even if my estimates are off by a factor of 10, Krakatoa spewed no more than a few thousand megatons of CO2.
As for human emissions, the estimates I find are 6,500 megatons of carbon per year (about 1 ton per person on the planet), which when combined with oxygen make about 24,000 megatons of CO2.
So you say that the Krakatoa eruption dwarfs 100 years of human activity, and I calculate that Krakatoa ~== 1 week of human activity. My estimates would have to be off by 3-1/2 orders of magnitude if your statement were correct. If you can find any numbers to back up your assertion, I would be happy to see them.