[Note: part of the answer is in the photo they provide with the press release below, but they don’t see it. – Anthony]
Greenland melting due equally to global warming, natural variations
The rapid melting of Greenland glaciers is captured in the documentary “Chasing Ice.” The retreat of the ice edge from one year to the next sends more water into the sea.
Now University of Washington atmospheric scientists have estimated that up to half of the recent warming in Greenland and surrounding areas may be due to climate variations that originate in the tropical Pacific and are not connected with the overall warming of the planet. Still, at least half the warming remains attributable to global warming caused by rising carbon dioxide emissions. The paper is published May 8 in Nature.
Greenland and parts of neighboring Canada have experienced some of the most extreme warming since 1979, at a rate of about 1 degree Celsius per decade, or several times the global average.
“We need to understand why in the last 30 years global warming is not uniform,” said first author Qinghua Ding, a UW research scientist in atmospheric sciences. “Superimposed on this global average warming are some regional features that need to be explained.”
The study used observations and advanced computer models to show that a warmer western tropical Pacific Ocean has caused atmospheric changes over the North Atlantic that have warmed the surface by about a half-degree per decade since 1979.
“The pattern of the changes in the tropical Pacific that are responsible for remarkable atmospheric circulation changes and warming in Greenland and the Canadian Arctic are consistent with what we would call natural variability,” said co-author David Battisti, a UW professor of atmospheric sciences.
Researchers say it’s not surprising to find the imprint of natural variability in an area famous for its melting ice. In many of the fastest-warming areas on Earth, global warming and natural variations both contribute to create a “perfect storm” for warming, said co-author John “Mike” Wallace, a UW professor of atmospheric sciences.
The natural variations in the new study related to an unusually warm western tropical Pacific, near Papua New Guinea. Since the mid-1990s the water surface there has been about 0.3 degrees hotter than normal. Computer models show this affects the regional air pressure, setting off a stationary wave in the atmosphere that arcs in a great circle from the tropical Pacific toward Greenland before turning back over the Atlantic.
“Along this wave train there are warm spots where the air has been pushed down, and cold spots where the air has been pulled up,” Wallace said. “And Greenland is in one of the warm spots.”
In previous studies, Wallace and Battisti have documented the existence of decades-long climate variations in the Pacific Ocean that resemble the well-known shorter-range El Niño variations.
This particular location in the tropical Pacific may be a sweet spot for generating global atmospheric waves. A series of studies led by co-author Eric Steig, a UW professor of Earth and space sciences, working with Ding and Battisti, showed that waves starting in the same place but radiating southward are warming West Antarctica and melting the Pine Island Glacier.
Researchers can’t say for how long the tropical Pacific will remain in this state.
“Our work shows that about half of the warming signal in Greenland comes from the predictable part – forcing of climate by anthropogenic greenhouse gases – but about half comes from the unpredictable part,” Steig said.
This makes shorter-term forecasts difficult, but helps scientists to make more accurate long-range projections.
“Nothing we have found challenges the idea that globally, glaciers are retreating,” Battisti said. “We looked at this place because the warming there is really remarkable. Our findings help us to understand on a regional scale how much of what you see is human-induced by the buildup of CO2, and how much of it is natural variability.”
The dramatic message of “Chasing Ice” remains true, authors say.
“There’s nothing in this paper that negates the message in the movie,” Wallace said. “Ice appears to be exquisitely sensitive to the buildup of greenhouse gases, more than we ever would have thought.” Natural variations could either accelerate or decelerate the melting rate of Greenland’s glaciers in coming decades, he said, but “in the long run, the human-induced component is likely to prevail.”
The research was funded by the National Science Foundation, UW’s Quaternary Research Center, the National Basic Research Program of China and the APEC Climate Center. Other co-authors are Lei Geng at the UW; Ailie Gallant at Australia’s Monash University; and Hyung-Jin Kim at South Korea’s APEC Climate Center.
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Note the photo provided with the press release, here it is in full resolution: http://www.washington.edu/news/files/2014/05/Greenland2010-5.jpg
And my enlargement of a section of it:
Note the black at the bottom of the melt pool, that’s carbon soot. That’s something the UW authors aren’t paying attention to.
As I explain here http://wattsupwiththat.com/2010/11/03/greenland-ground-zero-for-global-soot-warming/
…it has a big effect on albedo, and thus absorbed solar insolation, likely far more so than CO2 forcing, as explained here: http://wattsupwiththat.com/2013/08/13/in-the-arctic-nearby-soot-may-be-a-larger-forcing-than-co2/
UPDATE: Here is a map showing albedo change, the text is from the link below:
http://www.climate.gov/news-features/understanding-climate/greenland-ice-sheet-getting-darker
Map of changes in the percent of light reflected by the Greenland Ice Sheet in summer (June-July-August) 2011 compared to the average from 2000-2006. Virtually the entire surface has grown darker due to surface melting, dust and soot on the surface, and temperature-driven changes in the size and shape of snow grains. Map by NOAA’s climate.gov team, based on NASA satellite data processed by Jason Box, Byrd Polar Research Center, the Ohio State University.
![MODISalbedo_greenland2011_610[1]](http://wattsupwiththat.files.wordpress.com/2014/05/modisalbedo_greenland2011_6101.jpg?quality=83)
Layman trying to ask a common sense question here:
Half the temperature increase? Really? Why not most of it? If the rest of the world is warming at a much slower rate then half that rate, maybe it’s much more than half?
What I don’t get is, with all this modelling and VERY (sarc) high climate sensitivity, how is it that there’s still life on earth?
Wouldn’t the extintion of the dinosaurs, due to a catastrophic event that obliterated the species, would have caused more damage than mere CO2 <0.04%v/v?
Now, I am not sure if the dinosaur extintion due to the meteorite is a fact or theory. But if it is a fact, shouldn't it shed some light on how resilent the climate is?
If they’re right, and 1/2 the warming is natural, then that about agrees with the recent lower estimates for sensitivity, and means that the expected 1.5C warming by 2100 is nothing to panic about.
So Steig has joined us at last!
I do not think that it matters in the short term that we do not understand ‘why’ this is happening. It can not be caused by global warming if the globe as a whole is not warming, effectively it is weather.
The problem we all share with the policies of our governments are being sidetracked by the constant need to understand how and why things happen. In reality we are not going to get some of the answers for another thousand years and we need to focus on ‘what’ happens and accept that the how and why will come later.
What is happening is that we are pumping ever increasing amounts of CO2 into the atmosphere but the world (by our best estimates) is not warming.
Get rid of all this green crap please ^.^
Anthony, is it ALL carbon soot? Does wind blown glacial dust, or atmospheric dust, also take on a dark color when submerged? Not disagreeing about albedo effect, just wondering if carbon is the only source of dark coloration at the bottom of a melt pool on a glacier.
“Ice appears to be exquisitely sensitive to the buildup of greenhouse gases, more than we ever would have thought.”
“…more than we ever would have thought.” — Is that not an indication that previous understandings were not quite right? It’s impressive that some areas are warming, but it doesn’t necessarily add to confidence.
Only half the temperature increase due to natural variations?
Why only half?
Why is it not uniform?
Because climate is a complex phenomena, not understood by climate models.
Anthony, do we have a good measure of the carbon deposition and volcanic ash over the years. It would be a good test of your hypothesis
Can someone point to a chemical analysis of the black stuff in that Greenland pond?
I’m sceptical that it is ‘soot’. Oh, and where does the red stuff that you see over arctic glaciers occasionally come from?
Dear Anthony,
Apparently the photo of your back yard snow with the soot don’t show up. Before I send out this link to my friends and fiends is it possible to make the photos work.
Cheers Chris Hisgen (BS Honours, Mathematics & Applied Mathematics, Columbian College, George Washington University, 1977)
christopher hisgen I’ll see if I can get those fixed – Anthony
Well done WUWT for finally starting to publish research papers that, like virtually all climate-related papers in Nature, attests to the reality of significant temperature increases caused by carbon dioxide emissions.
REPLY: So like the authors of the paper, you missed what was in the photo too? – Anthony
Well I would first want to answer the Question:-
Why is (was) it, that BEFORE the last 30 years, global warming WAS uniform.
It’s not supposed to be; everybody knows that the poles warm faster, because they can’t cool as fast as the tropics do, and because of the equator to polar temperature gradient, heat constantly flows from equator to poles. It’s that second law thingy !
The hottest tropical desert surfaces, radiate at about twelve (12) times the radiation rate of the coldest polar regions.. That’s for +60 dg. C hottest daytime summer desert surfaces, to -94 deg. C Antarctic highlands Winter midnight..
But the science is settled, right? (/sarc off)
He’s claiming that the anthropogenic global warming part is the predictable part? Really?
Did those predictions suddenly come true while I slept? Cause when I went to bed last night, they were dead wrong for coming up on two decades.
And now this guy is telling us that half of the northern polar warming – the warming that is just barely holding the global average at zero warming – at least half of that is natural?
He’s simultaneously proving that “global warming” predictions are more wrong than most people realize, while asserting that very same predictability.
Idjits.
I noticed the black snow, not the black water. And when you added the blown up section the dirty canyon walls. I had assumed (perhaps in error) that the water was deep there because it is filling a canyon and thus no light there and that’s why it is black.
Either way, I’ve noticed the leave shaped holes in my skating rink after a leaf lands on it and the sun shines.
During an interglacial period, glaciers should be receding. That is what happens during an interglacial period which is what we are now in, and have been in for that last 11,500 years. If glaciers started growing, then there would be cause for concern. I do wonder though how they arrived at manmade CO2 being responsible for half the warming recently. When glaciers were receding during the Holocene Optimum at a much higher rate than they are now, natural causes were doing 100% of the job, right?
Hot under the collar says:
May 8, 2014 at 7:41 am
Only half the temperature increase due to natural variations?
Why only half?
Why is it not uniform?
Because climate is a complex phenomena, not understood by climate models.
More importantly, not understood by those who programme the models! I still gasp at the arrogance of climate modellers, who programme their models to show a given amount of warming for a given amount of CO2 & a pre-fixed climate sensitivity, & they claim that the answer coming out the other end is right!
Billy Liar asks “where does the red stuff you see on glaciers come from?”
That red stuff is a highly adapted bacteria called Chlamydomonas nivalis. The red tint is due to carotenoid pigments which protect them from UV. Where I live in the Canadian Rocky Mountains, these bacteria bloom around August when temps are above freezing.
No soot in the pool ! Just a photograph, low sun angle, shadow and diminished illumination against a very bright foreground on top ! Particulate measured in Firn and glacier ice is at the ppm level. Not enough to make a difference.
REPLY: No, sorry, you are wrong. It’s soot, dust, etc. people have sampled the bottom of those pools. Read the links provided before inserting foot in mouth. See map I’m adding from NASA showing deposition – Anthony
Stupid question: how do you know it’s soot and not some dark tunnel carved into the ice?
Dave in Canmore says:
May 8, 2014 at 8:09 am
Thanks Dave! I’ve seen it in Iceland in the summer. There’s plenty of black stuff there too but it is all rock flour, not ‘carbon’.
If the Alpine glaciers can look pink in late summer from all the Saharan dust they pick up I’m pretty sure the Greenland ice cap can pick up plenty of black dust from the glaciers grinding away at the periphery of the island.
I get so tired of the overworked “perfect [storm”] phrase. I never realized just how many perfect storms there were until I started following the AGW arguments. And was anyone else impressed by the statement that the tropical Pacific surface temperature was .3c “hotter?” Can anyone REALLY believe a rise in temperature of .3c is truly “hotter?” It’s really silly stuff like that that truly throws a lot of suspicion on whatever else they try to say. Oh yes, and the unpredictable natural variation makes it difficult to make short term prediction but easier to make long range prediction. Huh? Can the author REALLY believe this? Uncertainty only exists on the sort term, it falls out as you get further out? Wow.
“If we can muddy the waters, so that no clear distinction exists between our climate change fraud-science and real climate science, then we can then claim whatever percentage we like as our drivers of change in future – in whatever proportion of science we decide and ascribe it to.”
A nice, flexible PR strategy. A bit like the rubbery and user-friendly term for all seasons : ‘Climate Change’.
To me the dark part looks like a deeper part of the water, i notice that there are no darker parts elsewhere or if it is does the movement of water carry it to one part.
The bottom of the picture shows discoloration of the snow- soot? that has melted and yet everywhere else looks pristine.