Arctic nearly free of summer sea ice during first half of 21st century

Apr 15, 2013
Arctic sea ice. Credit: NOAA

For scientists studying summer sea ice in the Arctic, it's not a question of "if" there will be nearly ice-free summers, but "when." And two scientists say that "when" is sooner than many thought—before 2050 and possibly within the next decade or two.

James Overland of NOAA's Pacific Marine Environmental Laboratory and Muyin Wang of the NOAA Joint Institute for the Study of Atmosphere and Ocean at the University of Washington, looked at three methods of predicting when the Arctic will be nearly ice free in the summer. The work was published recently online in the publication Geophysical Research Letters.

"Rapid loss is probably the most visible indicator of ; it leads to shifts in ecosystems and economic access, and potentially impacts throughout the ," said Overland. "Increased physical understanding of rapid Arctic and improved models are needed that give a more detailed picture and timing of what to expect so we can better prepare and adapt to such changes. Early loss of Arctic sea ice gives immediacy to the issue of climate change."

"There is no one perfect way to predict summer sea ice loss in the Arctic," said Wang. "So we looked at three approaches that result in widely different dates, but all three suggest nearly sea ice-free summers in the Arctic before the middle of this century."

NOAA scientists explore the Arctic during a 2005 mission. Credit: NOAA

Overland and Wang emphasized that the term "nearly" ice free is important as some sea ice is expected to remain north of the Canadian Archipelago and .

  • The "trendsetters" approach uses observed sea ice trends. These data show that the total amount of sea ice decreased rapidly over the previous decade. Using those trends, this approach extrapolates to a nearly sea ice-free Arctic by 2020.
  • The "stochasters" approach is based on assuming future multiple, but random in time, large sea ice loss events such as those that occurred in 2007 and 2012. This method estimates it would take several more events to reach a nearly sea ice-free state in the summer. Using the likelihood of such events, this approach suggests a nearly sea ice-free Arctic by about 2030 but with large uncertainty in timing.
  • The "modelers" approach is based on using the large collection of global climate model results to predict atmosphere, ocean, land, and sea ice conditions over time. These models show the earliest possible loss of sea ice to be around 2040 as greenhouse gas concentrations increase and the Arctic warms. But the median timing of sea ice loss in these models is closer to 2060. There are several reasons to consider that this median timing of sea ice loss in these models may be too slow.
"Some people may interpret this to mean that models are not useful. Quite the opposite," said Overland. "Models are based on chemical and physical climate processes and we need better models for the Arctic as the importance of that region continues to grow."

Taken together, the range among the multiple approaches still suggests that it is very likely that the timing for future sea ice loss will be within the first half of the 21st century, with a possibility of major loss within a decade or two.

Explore further: Synchronization of North Atlantic, North Pacific preceded abrupt warming, end of ice age

More information: onlinelibrary.wiley.com/doi/10… 2/grl.50316/abstract

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User comments : 12

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LariAnn
1.8 / 5 (15) Apr 15, 2013
NO mention is made of sea ice thickness or volume as contrasted with visible sea ice area coverage. This would make a big difference as a 10 meter thick, 100 sq km ice layer would take much longer to melt than a 2 meter thick, 100 sq km layer. From a satellite, or even a visual inspection on the surface, the sea ice area covered would appear the same.
Shootist
1.5 / 5 (23) Apr 15, 2013
Think of all the wonderful petroleum . . . and gold . . .

Think of all the carbon saved by shipping using an open Northwest Passage.

Hoo haw! Drill here drill now.
VendicarE
3.7 / 5 (17) Apr 15, 2013
As the U.S. grain belt reverts back to desert ShooTard thinks he can eat oil.

Pure Idoicy.
Lurker2358
3 / 5 (13) Apr 15, 2013
As the U.S. grain belt reverts back to desert


I originally thought that as well, but the computer models should that about the eastern half to 2/3rds of the grain belt will actually get more precipitation. A recent model even showed half of Oklahoma, Kansas, and Nebraska getting more precipitation.

===
LariAnn:

The thickness of the majority of the ice is known to within 10cm margin of error.

Microwave satellite imagery, space-based radar, and sonar from submarines, etc, allow 3-d mapping.
PeterParker
4.5 / 5 (8) Apr 15, 2013
"A recent model even showed half of Oklahoma, Kansas, and Nebraska getting more precipitation." - LariAnn

Model resolution is not sufficient to draw such conclusions definitively.

LariAnn
1.8 / 5 (5) Apr 15, 2013
"A recent model even showed half of Oklahoma, Kansas, and Nebraska getting more precipitation." - LariAnn

Model resolution is not sufficient to draw such conclusions definitively.


PeterParker - your quote above attributes the comment to me - i did not make that comment. My actual comment is the first one made reference this article.
RealityCheck
2.6 / 5 (11) Apr 15, 2013
Hi Lurker:
...the computer models should that about the eastern half to 2/3rds of the grain belt will actually get more precipitation. A recent model even showed half of Oklahoma, Kansas, and Nebraska getting more precipitation.
If so, then the question becomes: Will the additional energy and unsettled patterns due to global warming translate that greater precipitation into more extreme and frequent weather events which destroy crops and infrastructure due to more unseasonal and destructive storm precipitation (snow, heavy rain, hail, tornadoes, ice storms etc)? It may be a lose-lose situation where areas which get less precipitation may suffer drought as its own extreme weather event; while areas with increased precipitation may suffer from more unsettled/unseasonal extreme events which more than negate benefits from increased atmospheric moisture load due to global warming. Not so straightforward when more energy/moisture creates new drought/storm extremes/pattern. :)
Neinsense99
2.9 / 5 (15) Apr 16, 2013
Interesting how the denialist crowd mocks computer modelling when it suits them, but them uses often-misinterpreted computer models when it suits them.
antigoracle
1.6 / 5 (14) Apr 18, 2013
Interesting how the denialist crowd mocks computer modelling when it suits them, but them uses often-misinterpreted computer models when it suits them.

Interesting how the AGW Alarmist Cult have a non-response when the "science" of their computer models is proven to be pure fabrications, all designed to propagate their agenda.

deepsand
2.3 / 5 (16) Apr 19, 2013
Most interesting is how AO consistently misrepresents when it serves his purposes, as he does here.
runrig
4.3 / 5 (6) Apr 19, 2013
Interesting how the denialist crowd mocks computer modelling when it suits them, but them uses often-misinterpreted computer models when it suits them.

Interesting how the AGW Alarmist Cult have a non-response when the "science" of their computer models is proven to be pure fabrications, all designed to propagate their agenda.

Anti:
Like weather modelling decades ago, as bigger supercomputers come along and science gains more information to feed into them, then they will get better. Meteorology wasn't discredited by modelling back then, in that it's physics held up, it's really just empirical fluid dynamics + observations. Climate is that + the drivers/feedbacks. Made difficult by uncertainty in cycles such as ENSO. They can do no other than indicate a rise stuttered by pauses as these overlying cycles are modeled. However they may be 180 deg out from reality - that we see now. The general upward trend is not discredited by that. Just that the phasing is wrong.
Cont
runrig
4.3 / 5 (6) Apr 19, 2013
Cont

Modelers know full well their models are just one outcome of many possible. That's why ensemble forecasts are done, combining different models and "perturbed physics". This is to remove as much of the uncertainty as possible. BTW: You are free to post any peer-reviewed evidence of the "science proven to be pure fabrication" claim of yours. I am not aware of any. Please provide evidence of the driver of the current warming ( surely you're not obtuse enough to deny that ) that so perfectly mirrors the warming, and it's physical modelling also fits, ( bar pauses caused by SST cooling cycles, low solar irradiation and increased pollution from the Far East ). And on top of that the orbital parameters favour neutral or even slight cooling of the NH. if you continually look at things through the filter of conspiracy and politics you will always come across as paranoid. I know it helps to understand the atmosphere or even the way science works. Sadly many on here don't.