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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.""
But as we can see.. the world is getting warmer.
Global warming is a natural occurance, however it IS being accelerated by high levels of industry.
Something to think about as we sit in our 18degC constantly cooled server rooms.
Psst... there are no penquins in the arctic.
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!
As the environment warms (be it from us or from nature), ocean water warms up on the surface.
... global warming may in fact lead to a few hundred years of arctic weather.
As the warm water of the atlantic follows the Gulf Stream northward along north america, and then towards europe, it cools and sinks, then following other currents southward. This heat transfer cycle is why Europe is not a lot colder than it is.
If the surface water heats up enough, it won't be able to cool off enough to sink when it gets to europe, the water underneath being cooler, the warm water will stay at the top.... shutting down the Gulf stream and cutting off the the flow of heat giving water to Europe. (The warm water moderates the weather helping to warm Europe).
With the Gulf Stream shut down, Europe will freeze until such time that the cycle is able to spontaneously start up again. The effects would be felt around the world.
Has this happened before? - in the mid 1600's. lasting for around 100 years (or 300 years depending on where you choose to pick the start and finish), the 'little ice age' gripped europe, eradicated viking settlements in Greenland and North America (before columbus). Inuit people kayaked as far south as Scotland. And people couldnt grow the food they needed to live. As late as the late 1700's, New York harbour froze solid in winter.
Fluctuations in solar output compounded with volcanic ash in the atmosphere may have been the cause of the little ice age, but the effect of a gulf stream shutting down may be the same
George Bush + Linux = "I will not let information get in the way of the fight against Windows"
No, but I did go through many years of geology and paleontology, so I can comment on what occured before. At one time there were almost no appreciable ice caps - the earth seemed to do pretty well during those times and survive (unless of course we are all zombies). Since we check temps during several of those periods by testing the amount of calcium carbonate deposited on the ocean floor (carbon dissolved into the ocean is an acid and dissolves calcium carbonate, temperature effects how much carbon can be dissolved in the water, thus average depth that it can dissolve the calcium carbonate is indicative of temps)I would also imagine that it would continue to do so this time around also.
I would suppose it would handle the same thing that has happened thousands of times the same way it has the other thousands of time regardless of who or what causes it (and it has happened faster than what we are seeing now well before humans existed). Note: that is not all life dies, all currents halt, all geologic processes halt, though they will most likely work somewhat differently.
------- Sorry about the spelling, I suffer from two problems. Dyslexia makes it difficult to spell well, lazy makes it
The ice is already in the water (ocean), so melting it is not going to increase the sea levels. Remember, water expands when it freezes and it goes back down when you melt it. If you don't believe me, fill a glass full of water and put it in the freezer.
The article seemed to imply that this was one of the ice masses that sits on land instead of floating in the water (many do) thus the level would increase. I do not know for sure and am too lazy too look it up for sure.
As the earth is still coming out of its last ice age, we shouldn't be too concerned about global warming. What we should be concerned about is desertification due to the lack of vegitation and depletion of the Ozone. Given the natural course of things, the earth will make big dinosaurs, not silly monkeys who play on computers and bitch at eachother.
well, I sorta agree - the article says they just know it was due to local heating (the area I live in has had two VERY mild summers in a row - we usually have at least a month of 105-110 degree weather - we haven't had a day above 98 in *two* years and average upper 80's to lwoer 90's, about 10 degrees cooler average). that being said many of the emissions aren't good for you - they aggrivate my chronic lung problems (probably cause them), kill off some more sensitive species, and many other things. I would advocate something in between what most seem to want (total reduction, do nothing).
As for the natural outgrowth being big dinno's - I don't really think so. The longest period with anything above single celled organisms (paleozoic) had fairly smallish creaturs - usually about the size of many of ours today - they died out (by far the largest extinction - well over 80 percent of *genuses* - one above species which the loss of a few many seem to think will destroy the earth - died out, though not that that is a good thing either). The next period had the giants - they died out. The only constant has been small bugs and down - they rule the earth, have for millions of years, and will for millions more. So this go around seems to be the silly monkeys bitching at each other as the top of the food chain.
------- Sorry about the spelling, I suffer from two problems. Dyslexia makes it difficult to spell well, lazy makes it
duh!
Food for thought related to this. http://www.whoi.edu/institutes/occi/currenttopics/ climatechange_wef.html
*It's not what you can do for the Dark Side but what the Dark Side can do for you!*
Is anyone an oceanologist?
I assume someone, somewhere, must be. Otherwise why would they bother to have the name?
KFG
"ozone layer is much healthier than in previous years"
In fact the WMO has realeased findings that say the ozone layer hole above the antartic has this year already reached the record size of 2000.
"The 2003 ozone hole remains similar to that observed in 2000, although more circular and
apparently more stable. The size of the ozone hole has increased from the 25 M km2 reported two weeks ago to
28 M km2, matching the record size observed during mid-September 2000. This is larger than the combined
areas of Canada, Mexico, and the United States, and contrasts the exceptionally small ozone hole last year that
split in two during late September. In recent years, the ozone hole has usually attained its maximum size
during mid-September. However, it is too early to predict with certainty whether the area has peaked this year." - From WMO report 18 Sep 2003.
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.
"The ice is already in the water (ocean), so melting it is not going to increase the sea levels."
I'm not sure if you're just talking about this ice shelf, but there's a helluva lot of ice sitting on Antarctica (ie land).
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
MEDIA KIT: Debunking Pseudo-Scholarship: Things a journalist should know about The Skeptical Environmentalist
Being bitter is drinking poison and hoping someone else will die
Transitions between ice-ages and warmer periods are extremely abrupt, in the order of decades rather than thousands of years. Furthermore, the *average* time between ice-ages might be 20000 years, but they are not particularly regular. Combined with "normal" fluctuations (mini ice-ages like in the 17th century), this means very little can be predicted from these variations in temperature.
Of course, it's still a good idea to minimize air pollution for other reasons, like actually being able to breath in a big city in summer.
Be wary of any facts that confirm your opinion.
Just FYI, YES, the amount of ocean water is staggering. BUT, it doesn't take that much fresh water to muck about with what's going on in the "conveyor" system. I'm too tired to search out sources, but check my journal later on today/tomorrow, I'll do it when I wake up ;-D. From what I've read, it's actually a pretty delicate balance...
Your mind is like a parachute. It works best when it's been opened.
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.
It was about several hundred square miles in extent at greatest (in winter), and it has been shedding Ice Islands for 40 years (last one in the mid-80s).
Last count, it was about 10 miles across, IIRC. The extent of ice cover out to sea varies a lot with season.
Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
A freshwater lake drained into the sea, the researchers reported. I think CNN is misinterpreting the following comment, also from the article: all of the fresh water poured out of the 20 mile (30 km) long Disraeli Fjord.
Disraeli Fjord is (was) freshwater on top and saltwater on bottom. The freshwater was due to the ice shelf, with the boundary at the bottom of the shelf. It would make sense that only the fresh part was drained. It's sad that this unique body of water is no longer that way.
The effects of global warming are not uniformly spread around the world. The arctic, both land and sea, are clearly warming. The equatorial areas may not be warming as much. The antarctic shows both warming and cooling: cooling in the the interior and warming.melting at the edges. Being a large, mountainous land mass complicates the climate there.
Water has a very high specific heat. It takes a LOT of heat to melt any large amount of it. To melt such a huge ice sheet as this, we're talking about the amount of heat from a blast furnace. That's a lot of heat that wasn't there before.
Every major ice age was preceeded by a period of warming. The global temperature is up, on average, 25% of what it takes to completely destabilize the global weather patterns (4-6 degrees C rise in the global average is all it takes). In the last hundred years, the amount of desert in the world has increased more than it has during any ascertainable period in the last million. The plant biomass is down to it's lowest in tens of millions of years. The extinction rate is higher than any fossil evidence shows it's ever been outside of global catastrophe, even taking into account the incomplete nature of the fossil record and allowing for much lower biodiversity in the past - and it's up several hundred times over just since the industrial revolution. There are thousands of species of plant and animal that only exist because of dedicated and constant (Not to mention expensive) human intervention - plants that can't polinate because the one insect that visits its flowers is extinct. Cafe Maron, once the finest coffee in the world, is now represented by thousands of cuttings of one plant - which is unable to produce male flowers. All over the world, major rivers - the Nile, Ganges, Colorado - fail to reach the sea most of the time. In the last two years alone, a number major ice sheets - which have remained intact in some cases since before the ice ages - have broken up.
You need to revisit your own logic, and english class. Given A>B,A,B, you concluded ~A. That's such a major fallacy they didn't bother making a rule about it when they developed sentential logic notation. The parent post didn't peg on any mechanism, it actually listed more than I've ever heard of.
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.
According to the BP statistical review, June 2002,
global consumption of liquid fossil fuels comes to
5595 KBbl/diem gasoline, 9247 KBbl/d. kerosene,
4873 KBbl/d. fuel oil, or 264, 435, and 230 MT/an,
respectively, for a total of ~929 MT/an. The
remainder of liquid fossil fuel production is
consumed by manufacture of materials or consists
of loss. Accepting BPs loss estimates, and assuming
all losses are gassified, that's 220 MT/an.
Coal consumption is 71.0% and natural gas is 60.0%
oil equivalent. To be generous, I include
production and refining losses to get a total
global annual carbon injection of
(1.00+0.600+0.710) * (220+264+435+230) MT
which comes to 2654 MegaTonnes annually, or
less than 443 Kg per person, annually.
This represents 90% carbon, which is 12/44 of
C02, for a total CO2 injection into the carbon
cycle of 1.46 metric tonnes per annum per capita,
or 8,750 MT/an total.
As you say, Krakatoa might conceivably have
emitted a few thousand megatons, but the human
emissions at that time were vanishingly small
in comparison to their current levels, so that
the eruption probably injected more CO2 than all
human activity during the *preceeding* century,
but in my estimation certainly injected an order
of magnitude less than the human activity during
the *following* century.
Perhaps it was equivalent to a century of human
injection at the rate prevailing at the time
the original estimation was made, and this statement
was later carried forward, and quoted on slashdot,
long after it was no longer accurate.
-I like my women like I like my tea: green-
What is preventing the ice on the mainland from melting? The sheet ice!
Once the sheet ice goes, its like a domino effect. The ice on the mainland will start to melt faster.
Thats essentially what I meant about the animals and so.
Vegans or not vegans.. it doesn't matter.
Animals in the arctic are specially suited only to the arctic! You take them away from their habitat, they will adapt, but only if they are left alone for the next 50 generations. And that is not going to happen because of man's intervention.
Do you find polar bears in texas? No.
Your using the " shallow analysis" method.
Its like stating, if spammers didn't spam, how would they survive? What will happen to the telemarketers once the do no call list goes into operation?
The people who benefit from this is miniscule.
10 times as more people will be the victim of stronger hurricanes, fishermen will have to contend with less yield etc..
Then even the bankers,insurers and sundry won't benefit.
I don't care if you take it as flamebait. Because it WAS flamebait.
Your statement about tankers or so benefitting from the opening of the passage was so illogical and uninformed that anybody with a saner mind can deal with it as flamebait.
Bush is on fire and its not good for my lungs.