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 American Geophysical Union publication Geophysical Research Letters.
"Rapid Arctic sea ice loss is probably the most visible indicator of global climate change; it leads to shifts in ecosystems and economic access, and potentially impacts weather throughout the northern hemisphere," said Overland. "Increased physical understanding of rapid Arctic climate shifts 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."
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 Greenland.
- 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.
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:
Declining sea ice to lead to cloudier Arctic: study
More information:
onlinelibrary.wiley.com/doi/10 … 2/grl.50316/abstract
LariAnn
Shootist
Think of all the carbon saved by shipping using an open Northwest Passage.
Hoo haw! Drill here drill now.
VendicarE
Pure Idoicy.
Lurker2358
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.
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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
Model resolution is not sufficient to draw such conclusions definitively.
LariAnn
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
Neinsense99
antigoracle
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
runrig
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
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.