From Penn State, note there’s no meltwater in this PSU provided photo, but there is evidence of black carbon (which increases solar radiation uptake) and sublimation (which due to a lack of precipitation, causes evaporation of ice directly into the air).
Greenland Ice: The warmer it gets the faster it melts
Melting of glacial ice will probably raise sea level around the globe, but how fast this melting will happen is uncertain. In the case of the Greenland Ice Sheet, the more temperatures increase, the faster the ice will melt, according to computer model experiments by Penn State geoscientists.
“Although lots of people have thought about sea level rise from the ice sheets, we don’t really know how fast that will happen,” said Patrick Applegate, research associate, Penn State’s Earth and Environmental Systems Institute.
If all the ice in the Greenland Ice Sheet melts, global sea level would rise by about 24 feet. In the last 100 years, sea level in the New York City area has only increased by about one foot. However, storm surges from hurricanes stack on top of this long-term increase, so sea level rise will allow future hurricanes to flood places where people are not ready for or used to flooding. A vivid example occurred during Hurricane Sandy when parts of the New York City subway tunnel system flooded.
Greenland might be especially vulnerable to melting because that area of the Earth sees about 50 percent more warming than the global average. Arctic sea ice, when it exists, reflects the sun’s energy back through the atmosphere, but when the sea ice melts and there is open water, the water absorbs the sun’s energy and reradiates it back into the air as heat. Arctic sea ice coverage has decreased over the last few decades, and that decrease will probably continue in the future, leading to accelerated temperature rise over Greenland. Floating ice does not add to sea level, but the Greenland Ice Sheet rests on bedrock that is above sea level.
Feedbacks in the climate system cause accelerated temperature rise over the Arctic. Other feedbacks in the Greenland Ice Sheet that contribute to melting include height-melting feedback. A warm year in Greenland causes more melt around the edges of the ice sheet, lowering the surface. The atmosphere is warmer at lower altitudes, so the now lower surface experiences even more melting. This process can lead to accelerated ice melt and sea level rise.
Another form of feedback occurs because ice sheets are large masses that want to spread. This spreading can either help preserve the ice sheet by allowing it to adjust to increased temperature or accelerate ice melting by moving ice to lower, warmer, places.
“Many studies of sea level rise don’t take into account feedbacks that could cause rapid sea level rise,” said Applegate. “We wanted to look at the effects of those feedbacks.”
The researchers looked at two models of the Greenland ice sheet that include some of the important feedbacks. The first model is a three-dimensional ice sheet model. The second model looks at a transect across the island and was developed by Byron Parizek, associate professor of geosciences and mathematics, Penn State Dubois. To run both models, Robert Nicholas, research associate, EESI, estimated how much warming might take place over Greenland using results from global climate models.
Both the three-dimensional and transect models showed that the time necessary for ice mass loss from the Greenland ice sheet decreases steeply with increases in temperature. Shorter time scales — faster melting — imply faster sea level rise. The interplay between the height-melting feedback and ice flow causes this acceleration.
“Our analysis suggests that the benefits of reducing greenhouse gas emissions, in terms of avoided sea level rise from the Greenland Ice Sheet, may be greatest if emissions reductions begin before large temperature increases have been realized,” the researchers state in a recent issue of Climate Dynamics.
Currently, about a billion people — 1 percent of the world population — live in areas that would be flooded by a three-foot sea level rise.
“If we are going to do something to mitigate sea-level rise, we need to do it earlier rather than later,” said Applegate. “The longer we wait, the more rapidly the changes will take place and the more difficult it will be to change.”
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Other researchers working on this project include Richard Alley, Evan Pugh Professor of Geosciences and Klaus Keller, associate professor of geosciences.
The U.S. Department of Energy, NASA and the National Science Foundation’s Network for Sustainable Climate Risk Management (scrimhub.org) supported this work.
Are they saying it took a computer model to figure out that ice melts faster at higher temperatures? If so, how did the guy who programmed the computer know to program that behavior into the model? It’s a chicken and egg conundrum. Which came first? Did our knowledge of the laws of physics come from models, or did the models come from our knowledge of the laws of physics?
Once that question is resolved, I have another one to ask: If a researcher programs his pet theory into a model, is the output of the model sufficient to prove his theory? If the answer is “no,” then I’m confused. Every climate scientist who rings the climate-change alarm bells acts as if their models prove their case, and anyone who disagrees is anti-science and a heretic. That just doesn’t add up.
What happened to Cowtan and Way’s claim that “Arctic temperature anomalies are changing approximately 8 times faster than temperatures over the planet as a whole”? Did they retract their claim? There’s a big difference between 50% and 800% more warming, isn’t there?
Loius
The Arctic Ocean has 14 Mkm^2 of the earth’s surface, 2.8% of the world’s surface. And has 0.0 of its thermometers.
(That’s from the pole to 70.9 north latitude.)
The high Arctic (between 70.9 latitude and the Arctic Circle) has 7.1 Mkm^2, 1.4 % of the earth’s surface.
And less than 0.01% of its thermometers.
Antarctica (and its surrounding sea ice) has 14.0 Mkm^2 of land ice + 1.5 Mkm^2 of shelf ice + 16 Mkm^2 of sea ice extents.
That 31.5 Mkm^2 is 6.2% of the earth’s surface – More than Africa or North America or South America or Europe or Australia.
And it only has a few isolated thermometers – but at least they kept in working order!
And those Antarctica thermometers show a consistent and gradual cooling since records began.
Does make you wonder, doesn’t it.
“the more temperatures increase, the faster the ice will melt, according to computer model experiments by Penn State geoscientists.”
Good. Some settled science at last.
The Average Albedo of Greenland by month this summer was:
June, 2014 –> 0.65164107
July, 2014 —> 0.603205
August 2014, —> 0.626172066
Source: MODIS sensors on NASA’s Aqua and Terra satellites
http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MCD43C3_M_BSA
Take away their calculator. Nine places after the decimal point is impossible!!
Ian M
It’s NOT all ‘black carbon’! Can anyone find research that shows the composition of the black stuff?
Here are some pictures from Southern Greenland:
http://www.meltfactor.org/blog/?p=1240
Scroll down the page to the second picture; note the caption:
… boots on the ice offer a close look (and to sample) impurities concentrating at the surface. The fact is, much of this dark material is from cyanobacteria and blue-green algae. Photo J. Box.
and they don’t come more alarmist than Jason Box.
Some of it may well be carbon black (since when did carbon black, the product of incomplete combustion, become ‘black carbon’?) from nearby wildfires:
http://www.meltfactor.org/blog/?p=1466
Billy Liar,
I’m pleased to see you raise an eyebrow at the claim that the pristine visage of the glacier is defiled principally or exclusively by carbon.
Both of my eyebrows are as elevated as they can be and my jaw is hanging, too.
I have stomped around on a number of different glaciers in BC, The Yukon and Alaska, and I have been struck always by how much debris tumbles from the lateral moraines onto the surface of the ice.
The Kokanee glacier, is underlain by granitic rock and that’s what comprises the till that is intercalated in the glacial mass. This material ranges from boulders to fine dust that is easily spread by the wind over the entire breadth. None of this is carbon. Silicon, aluminum, potassium, iron, magnesium.
Chugach Mountains are basalt; no carbon there!
I’m not buying it.
During the Hypsithermal interval about 5,000 years or so ago, sea level rose 2 meters.
So, 3 meters is doable by about the year 2200..
According to the orthodox view of climate science, there is no way to change this apart from closing down our industrial civilization.
Forget it. That is not going to happen. No nation anywhere will vote for a government that promises the kind of future that would be in store for a traditional economy not based on industrialization.
Greenland lakes: http://www.natureworldnews.com/articles/12140/20150121/rising-temps-causing-greenlands-meltwater-lakes-to-drain-at-dramatic-rate.htm
While we are challenging the trutherisms of “black carbon”, I’d like to query something else used in the title and common in posts here: sublimation of water. Decades ago, in my early chem courses, I was taught that water does not sublimate, i.e., change phase directly from a solid to a gas. That, in fact, it passes through a brief transitory melting phase before being dispersed as vapour.
I’ve never pursued the question beyond the initial training, but for advanced chemists here, has this perspective changed since my early alchemy courses?
Why do I get the feeling climate science modelers are frustrated video game designers? Come to think of it, a climate science video game — I’m thinking Steyn vs. Mann, etc. — might be kind of fun.
“If all the ice in the Greenland Ice Sheet melts, global sea level would rise by about 24 feet. ”
The papers writen on this subject always mention that.
If all the ice on Greenland melts it means we have no more seasons, which means we have been hit by something big that changed the worlds axis to 90 degrees with the north pole facing the sun at all times. My guess is that Global Warming will look meaningless in the shadow of that calamity. But then, there will be no one around to prove that AWG didn’t cause the ice sheets to melt.
Call me a close minded man, but the title containing the words “Penn State researchers” made me automatically stop reading and label the article BS. I have read the comments, however, and found them entertaining as well as supportive of my close minded conclusion.
“the words “Penn State researchers” made me automatically stop reading and label the article BS.”
Do you prefer uneducated laymen doing this work?
I spread my pellet stove’s soot over our southern walkway instead of shoveling it. That works very well in ridding it of snow.- even when the temps are below freezing. The northern walkway doesn’t see any winter sun…
“Currently, about a billion people — 1 percent of the world population — live in areas that would be flooded by a three-foot sea level rise.”
Whoah — Earth has 100 billion people? At any rate, I expect those billion people will have to move 3 feet higher. I move 30 feet higher every day.