From the University of British Columbia press office:
Greenland ice sheet flow driven by short-term weather extremes, not gradual warming: UBC research
Sudden changes in the volume of meltwater contribute more to the acceleration – and eventual loss – of the Greenland ice sheet than the gradual increase of temperature, according to a University of British Columbia study.
The ice sheet consists of layers of compressed snow and covers roughly 80 per cent of the surface of Greenland. Since the 1990s, it has been documented to be losing approximately 100 billion tonnes of ice per year – a process that most scientists agree is accelerating, but has been poorly understood. Some of the loss has been attributed to accelerated glacier flow towards ocean outlets.
Now a new study, to be published tomorrow in the journal Nature, shows that a steady meltwater supply from gradual warming may in fact slow down glacier flow, while sudden water input could cause glaciers to speed up and spread, resulting in increased melt.
“The conventional view has been that meltwater permeates the ice from the surface and pools under the base of the ice sheet,” says Christian Schoof, an assistant professor at UBC’s Department of Earth and Ocean Sciences and the study’s author. “This water then serves as a lubricant between the glacier and the earth underneath it, allowing the glacier to shift to lower, warmer altitudes where more melt would occur.”
Noting observations that during heavy rainfall, higher water pressure is required to force drainage along the base of the ice, Schoof created computer models that account for the complex fluid dynamics occurring at the interface of glacier and bedrock. He found that a steady supply of meltwater is well accommodated and drained through water channels that form under the glacier.
“Sudden water input caused by short term extremes – such as massive rain storms or the draining of a surface lake – however, cannot easily be accommodated by existing channels. This allows it to pool and lubricate the bottom of the glaciers and accelerate ice loss,” says Schoof, who holds a Canada Research Chair in Global Process Modeling.
“This certainly doesn’t mitigate the issue of global warming, but it does mean that we need to expand our understanding of what’s behind the massive ice loss we’re worried about,” says Schoof.
A steady increase of temperature and short-term extreme weather conditions have both been attributed to global climate change. According to the European Environment Agency, ice loss from the Greenland ice sheet has contributed to global sea-level rise at 0.14 to 0.28 millimetres per year between 1993 and 2003.
“This study provides an elegant solution to one of the two key ice sheet instability problems identified by the Intergovernmental Panel on Climate Change in their 2007 assessment report,” says Prof. Andrew Shepherd, an expert on using satellites to study physical processes of Earth’s climate, based at the University of Leeds, the U.K.
“It turns out that, contrary to popular belief, Greenland ice sheet flow might not be accelerated by increased melting after all,” says Shepherd, who was not involved in the research or peer review of the paper.
The research was supported by the Canada Research Chairs Program, the Natural Sciences and Engineering Research Council of Canada, and the Canadian Foundation for Climate and Atmospheric Sciences through the Polar Climate Stability Network.
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h/t to Charles the Moderator
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“but has been poorly understood……….”
“Schoof created computer models………”
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and all this time I was under the impression that you had to understand
something in order to create a computer game………..
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“This study provides an elegant solution”
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guess not, as long as you like the results………….
OT – I THINK THIS IS IMPORTANT!
RUSSIAN PM PUTIN OFFERS FIREWOOD TO GERMANY
Putin Suggests Germany Replaces Nuclear with Firewood
Russian prime minister Vladimir Putin has told German businessmen that they may have to rely on Russian firewood for heating if they do not want to construct new nuclear power plants or bring in Russian gas supplies. At a business conference organized in Berlin by the German newspaper Sueddeutsche Zeitung, Putin recognised that “the German public does not like the nuclear power industry for some reason.” He continued: “But I cannot understand what fuel you will take for heating. You do not want gas, you do not develop the nuclear power industry, so you will heat with firewood?” Putin then noted, “You will have to go to Siberia to buy the firewood there,” as Europeans “do not even have firewood.”
World Nuclear News
1 Dec 2010
http://www.world-nuclear-news.org/newsarticle.aspx?id=28907
Ted Gray says:
December 8, 2010 at 3:11 pm
“RUSSIAN PM PUTIN OFFERS FIREWOOD TO GERMANY”
Thats hilarious! AGW:Putin = 0:1
But the science WAS already settled… Oh no!
It’s worse than we could ever think, that is, nothing is happening due to global warming after all, except the big freeze. No wonder more and more scientists are coming out of the woodworks and declare openly their skepticsm on AGW or, as it is called now: CFDtGW(Catastrophic Freezing Due to Global Warming)
http://www.climatedepot.com/a/9035/SPECIAL-REPORT-More-Than-1000-International-Scientists-Dissent-Over-ManMade-Global-Warming-Claims–Challenge-UN-IPCC–Gore
Can(cun) anyone tell me where Al Gore is?
Lost me when I read..could, may, computer model…
There is too much use of the term ” accelerate” when the trend line is linear. Acceleration implies a constant increase in velocity e.g. an object will accelerate (assuming zero air resistance) under gravity and implies a constant force applied to a frictionless object.
A moving glacier is not moving friction free.
They are not trying to frighten people are they ?
From the article “According to the European Environment Agency, ice loss from the Greenland ice sheet has contributed to global sea-level rise at 0.14 to 0.28 millimeters per year between 1993 and 2003″…
.14 mm / 25.4 = .006 inches times 10 years = .055 inches
.28 mm / 25.4 = .011 inches times 10 years = .110 inches
Head for high ground!
“This certainly doesn’t mitigate the issue of global warming,
No ofcourse it doesn’t, who’d be silly enough to think it would?
Sometime in the future, well past my lifetime, humans will be huddled around low lattitudes and altitudes, glaciers of a new ice age encroaching upon them, yet there’ll still be a paper released by a some wag that says “Snowball Earth maybe caused by solar and planetary perturbations, but this certainly doesn’t mitigate the issue of global warming.”
When will they stop? When will they realise the damage they are doing to science? When will they care?
Yet one more talking point leaves the building.
Its encouraging to see more thought and testing of alternative theories AND using computer models to explore, test and check. That’s advancement of scientific knowledge and will no doubt spur others on to further and better understanding of the issues that were grabbed and used as (incorrect) headlines.
Interesting the paper seems to have been embraced by Nature, the journal that seemingly worked with the team to stifle alternative theory to the all conquering CAGW meme.
I do love the spin though, and the “contrary to belief” replacing” our “solid scientific consensus” tales of old CAGW. Change for the good of science? or is this new confession “we got it slightly wrong” , a case of the Fabian wolf disguising itself as just a sheep, to sell another agenda?
I hope it signals a change of direction for the good of science?
Is that 100 billion tonnes per year the NET loss; or is it just how much melts or falls off each year.
so how much does it gain every year ?
“The ice sheet consists of layers of compressed snow and covers roughly 80 per cent of the surface of Greenland. Since the 1990s, it has been documented to be losing approximately 100 billion tonnes of ice per year – a process that most scientists agree is accelerating, but has been poorly understood.”
So, a gigatonne is 1 billion metric tonnes, and 100 gigatonnes = 100 billion tonnes. A gigatonne of ice weighs about 9% less than a gigatonne of water, so lets use water, as it gives us a nice fudge factor. Now a metric ton of water has a volume of 1 cubic metre, so a gigatonne of water has a volume of 1 cubic kilometre.
And 100 gigatonnes = 100 cubic kilometres.
Greenland has, I believe, an estimated 2.6 million cubic kilometres of ice?
And I’m supposed to be worried about it losing 100 cubic kilometres a year for the last 20 years? That would be 2000 cubic kilometres, or less than .0008 of it’s estimated volume, over the last 20 years?
At what point does that disappear into the error range of the estimates themselves?
In other words we don’t known why its happening and this is one idea for a cause .
Which is actual fair enough , and certainly makes a change from ‘we know for a fact its down to AGW’ when that is not the case. But its underlines again the point that there are quite a few of issues were the sceince is far from settled , which is what the secptics have been saying all along.
Ted Gray:
December 8, 2010 at 3:11 pm
Putins got Merkel by the short and curlys.
His blunt sarcasm is refreshing. Though funny to read, it’s sad for the Germans, on hands and knees at the feet of the Russians, (yet again).
Well, they will form government with greenies won’t they. Reap sow and all that.
Thnx Ted, being a political piece, I passed it onto Andrew Bolt (link at side bar) with due citation to you.
I think that the AGWs will explain it this way–Global warming will cause more rain water in the Greenland area increasing the liquid water that causes glacier melt to accelerate and a large increase in the rate of sea level rise across the globe. The U.S. must increase it’s payments to the U.N. so they can stop this horrible problem before we all perish. All U. S. citizens should also sign up to stop any increase in “die hydrogen monoxide” increase which is another terrible problem.
re post by Ted Gray says: December 8, 2010 at 3:11 pm
ROFLMAO!! Well, now we know Putin has a wry sense of humor. That, and he’s being far more practical than the German & US & UK governments seem to be.
re post by Baa Humbug says: December 8, 2010 at 4:05 pm
They’ve already covered that very eventuality – should it occur, clearly we’ve just passed some ‘tipping point’ or another with all the CO2 we released. Sigh.
Gee whiz, this is getting sad. Really? You mean that ice existing in -40 deg temps vs -50 degree temps isn’t the reason for ice loss? Whodda thunk it? Glacier movement might be the cause after all? Wow, what will they think of next?
Putin cracking wise! ahahaha
There’s Science and there’s Computer Modelling. This isn’t Science.
Interesting paper. Too bad it will be ignored in IPCC AR5 in favor of some obscure WWF gray literature.
A steady increase of temperature and short-term extreme weather conditions have both been attributed to global climate change.
it’s still blamed on global warming
Inevitably still some spin but at least there is recognition that something other than global warming can drive nature.
Meanwhile in the UK, lets hope it is just weather and not climate that we are presently experiencing since if the recent trend (now 3 cold winters in a row) continues, the UK will not be a pleasant place to live. Now, if only the Government could divert some of the money it is wasting on windmills to sorting out the infrastructure so that the UK does not grind to a halt when it keeps on experiencing a 1 in 30 years or 1 in 100 cold snap we would not be forced to call in the army to dig us out.
http://www.dailymail.co.uk/news/article-1336705/UK-big-freeze-Army-standby-coldest-December-100-years.html
UBC is one of the “big boy” Universities in Canada, I hope to go there and finish my Chemistry and Physics degrees for a career in Nuclear Industry and and related good stuff (like space travel).
This is an academic “earthquake” in Canada.
Guess who the cave dwellers facing the rock fall are?
If you guessed the “ass”orted mixed fruit and nuts that make up the AGW crowd then you are correct.
dwright 5:41 pm PST
I try not to laugh at most people who have NO idea about global weather or global temperatures (or the history of either).
The recent publications supporting global warming always seem to show the “ice-hockey stick” graph extending back about 1500 years. The graph shows an extreme rise in temperature over the past 100 years or so. I don’t deny any large rise, but I like to add some scientific data…
1. The Earth is coming out of “the little ice-age;” and
2. There are other graphs showing temperatures over longer periods of time.
The PALEOMAP project has a great graph showing average global temperatures (estimates, of course) over 2 billion years. If I was to base my argument on a graph, I would look at the graph presented and say we were just getting back to normal temperatures…
Most people are trying to SPIN facts to fit their “political” or “social” objectives rather than look at facts and outcomes. Man does affect the environment (as do other living things and chemicals). Limiting our impacts isn’t a bad thing, and I do like the islands in the Pacific and the land-mass of Florida. If I can limit my impacts to keep water lower in those areas I will. I also like skiing (in California and elsewhere), so I will do what I can to keep snow in the lower 48.
However, most people do need to get lots of education re: global temperatures and many other topics…