From the University at Buffalo, new evidence that large ice sheets can grow/disappear quickly on decadal scales in response to regional temperature changes. A descriptive video follows.
How fast can ice sheets respond to climate change?
Scientists report that prehistoric glaciers reacted rapidly to a brief cold snap, providing a rare glimpse of glaciers’ response to past climate change
BUFFALO, N.Y. — A new Arctic study in the journal Science is helping to unravel an important mystery surrounding climate change: How quickly glaciers can melt and grow in response to shifts in temperature.
According to the new research, glaciers on Canada’s Baffin Island expanded rapidly during a brief cold snap about 8,200 years ago. The discovery adds to a growing body of evidence showing that ice sheets reacted rapidly in the past to cooling or warming, raising concerns that they could do so again as the Earth heats up (or cools down – Anthony).
“One of the questions scientists have been asking is how long it takes for these huge chunks of ice to respond to a global climate phenomenon,” said study co-author Jason Briner, PhD, a University at Buffalo associate professor of geology. “People don’t know whether glaciers can respond quickly enough to matter to our grandchildren, and we’re trying to answer this from a geological perspective, by looking at Earth’s history.”
“What we’re seeing,” he added, “is that these ice sheets are surprisingly sensitive to even short periods of temperature change.”
Briner’s colleagues on the study included lead author Nicolás Young, who worked on the study as part of his PhD at UB and is now a postdoctoral researcher at Columbia University’s Lamont-Doherty Earth Observatory; Dylan H. Rood of the Scottish Universities Environmental Research Centre and the University of California, Santa Barbara; and Robert C. Finkel of UC Berkeley.
The research, scheduled to appear in Science on Sept. 14, found that mountain glaciers on Baffin Island, along with a massive North American ice sheet, expanded quickly when the Earth cooled about 8,200 years ago.
The finding was surprising because the cold snap was extremely short-lived: The temperature fell for only a few decades, and then returned to previous levels within 150 years or so.
“It’s not at all amazing that a small local glacier would grow in response to an event like this, but it is incredible that a large ice sheet would do the same,” Young said.
This video detailing the findings and the information in this press release is embargoed until 2 p.m. U.S. Eastern Time on Thursday, Sept. 13, 2012.
To conduct the research, Briner led a team to Baffin Island to read the landscape for clues about the pre-historical size and activity of glaciers that covered the island.
Moraines — piles of rocks and debris that glaciers deposit while expanding — provided valuable information. By dating these and other geological features, the scientists were able to deduce that glaciers expanded rapidly on Baffin Island about 8,200 years ago, a period coinciding with a short-lived cold snap.
The researchers also found that Baffin Island’s glaciers appeared to have been larger during this brief period of cooling than during the Younger Dryas period, a much more severe episode of cooling that began about 13,000 years ago and lasted more than a millennium.
This counterintuitive finding suggests that unexpected factors may govern a glacier’s response to climate change.
With regard to Baffin Island, the study’s authors say that while overall cooling may have been more intense during the Younger Dryas, summer temperatures may have actually decreased more during the shift 8,200 years ago. These colder summers could have fueled the glaciers’ rapid advance, decreasing the length of time that ice melted during the summer.
Detailed analyses of this kind will be critical to developing accurate models for predicting how future climate change will affect glaciers around the world, Briner said.
The study was funded by the National Science Foundation.
I found that some aspects of this area of the North Canada are unique, with a particular relevance to the North Hemispheres climate change; resulting in the first climate related article I wrote in 2009.
http://www.vukcevic.talktalk.net/NATA.htm
It was considered as a bit of pure speculation, but now even NASA scientists are ‘speculating’ in the same direction. See links 1 and , 2
This is what they seem to be arguing:
If you turn off the power to the freezer all the ice melts. Therefore, if you increase the power to the freezer with a lot of ice in it, a lot more ice will appear.
Maybe not the best analogy, but what these people are doing is looking at the transition zone between glacial and interglacial. And then they are trying to suggest that because there is evidence it warms going from interglacial to glacial or cools quickly going from glacial to interglacial. That you must get massive warming from an interglacial to a ??Help there’s not term for a period warmer than an interglacial??? it doesn’t happen.
Here’s more of the same logic
… if you cut through a 10m tree once it will fall down 10m. Therefore if you cut it twice it will fall 20m
…. if your kid drops one boiled egg on your suit, it costs £10 at the dry cleaner, therefore if they drop two it will cost £20.
…. if you create one global warming scare academics will be flooded with $100million** of grants, so if they create two global warming scares, they will get $200million
In other words, why the climate may relatively easily (in geological timescales) transit from glacial to interglacial, there is clearly something stopping it getting much warmer than an interglacial and much cooler than a glacial, and that’s because the sensitive area where ice and grow and strink is relatively small. So, once you’ve melting all the easily melting ice, not much more will ever melt.
**Just a guess.
Steve R. and Caleb;
Yes as you note, an ice free arctic ocean that allowed moist air to move over the northern land masses and thus yield very high levels of precipitation in the form of snow is one of several mechanisms suggested for rapid glaciation of the region. It `was’ a good theory and generally accepted as being realistic. However that seems to have been totally forgotten in the new era of glaciology and probably isn’t even mentioned in all the new, artsy – fartsy environmental science degrees being offered at universities. These degrees aren’t worth the paper they are printed on. In fact it is quite common to meet smart geology students that started out in these programs and withdrew to take geology. The reason? They say the courses were crap, little science and just CAGW propaganda.
Don’t see why this is remarkable. It’s been shown that pretty much all the subtropical & tropical mountain glaciers present today formed during the LIA and weren’t present during the MWP.
So if increasing CO2 causes warming then removing CO2 can cause an ice Age!
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Steve R says:
September 13, 2012 at 3:29 pm
I think we should consider the possibility that the rapid response of the glacier might have less to do with temperature than we would otherwise think. Imagine that for some reason warm tropical moisure were diverted to high arctic latitudes and into an ice free Arctic ocean. The adjacent continental landmasses could easily be transformed from a Arid climate to a climate of extreme blizzard conditions, with yearly snowfalls perhaps as high as in the Cascades.
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Interesting. Watch Barrow, AK & other Arctic Ocean shore sites for snowfall amounts this autumn. IIRC, Barrow had record snow in autumn 2007.
I don’t know enough to comment intelligently about their hypothesis.
However I will note that there are engravings/lithographs and paintings of small glaciers in europe and elsewhere that have varied dramatically over the last 300-400 years in how much they extended down their valleys, so I’d not be shocked that it’s possible that given relatively small variations in weather over a couple of decades/centuries that largish ice sheets could A. Form and B. Extend ( and then reverse right back)
When you read about the various Columbia river “incidents” where massive inland seas drain ,and this I’m sure has happened elsewhere in the world (e.g. perhaps the Black sea basin filling with salt water )and temporarily disrupt ocean salinity/temp/currents, one could easily imagine that massively increasing/decreasing precipitation/cloudiness , amount of surface water in lakes, causing huge effects on the other end of the continent, but going from there to proving causality of events happened in blinks of geological time scales. Uhm. Ok. Right. Hard to prove.
As many commenters have noted; they never mention precipitation, the other way to shrink/expand a glacier.
In the too difficult box perhaps?
tty says:
September 14, 2012 at 12:02 am
We probably came quite close to a new Ice Age during the LIA.
Now that would be an interesting modeling exercise – how close?
An example of a sudden expansion of a glacier is the well known Nigardsbreen (“nine farm glacier”) in Norway