Global warming could melt summer Arctic sea ice by the end of the century, scientists say, making for an ice-free North Pole for the first time in more than a million years.
With no apparent natural mechanisms to maintain the summer sea ice, the question is no longer whether such melting could happen, but when and with what impacts, says a team of researchers led by University of Arizona professor Jonathan Overpeck. The group, which included two Boulder scientists, published its findings in this week's Eos, the weekly newspaper of the American Geophysical Union.
The impacts will go well beyond Santa's workshop needing pontoons. The Arctic plays a major role in the Earth's climate system, and sea-ice cover drives much of its current behavior. When highly reflective ice melts, darker oceans and land absorb more heat, creating a positive feedback loop of melting.
"If we lose the sea ice in the summer, there will be strong downstream effects," said Mark Serreze, a senior research scientist with the Cooperative Institute for Research in Environmental Sciences and one of the paper's co-authors. "The Arctic is the heat sink of the Northern Hemisphere, and the equator the heat source. If we change the nature of that Arctic heat sink, we radically alter that system."
CIRES is a collaboration between the University of Colorado and the National Oceanic and Atmospheric Administration.
Serreze said some climate models predict complete summer sea-ice melting by 2070, but that the recent trend toward extreme melting could push the date up to 2040.
Changes already are apparent.
Sens. Hillary Clinton, D-N.Y., and John McCain, R-Ariz., toured Alaska last week to view firsthand such warming effects as melting permafrost and beetle-infested forests. Researchers have found that polar bears and seals are losing weight from shorter feeding seasons due to receding sea ice.
Future impacts could have broader reach. Flushing sea ice into the Arctic Ocean could slow thermohaline circulation, the ocean conveyor belt that moves warm equatorial water into the North Atlantic and saves Europe from Canadian winters.
But the summer melt also could strengthen the conveyer belt, Serreze says.
"Which wins, we don't know," Serreze said. "That's one of the big mysteries."
Marika Holland, a National Center for Atmospheric Research scientist and co-author of the new paper, uses climate models to understand the polar climate. She said some model runs are showing abrupt changes in sea ice that would reverberate throughout the system.
"I think it's coming out of numerous studies that the Arctic is changing rapidly and in ways we haven't seen for a long time," Holland said.
Arctic sea ice appears to be in rapid retreat already. Julienne Stroeve, a scientist with the University of Colorado's National Snow and Ice Data Center, said 2005 could surpass 2002 as the lowest sea-ice summer in a century.
Stroeve uses satellite data to monitor Arctic sea-ice cover, which reaches its annual minimum in September.
"So far, the numbers are pretty disturbing," Stroeve said. "The rate of change has taken us by surprise a little bit. I think it's changing a lot quicker than we expected."
2006-12-04 03:09:28
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answer #1
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answered by Brite Tiger 6
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Many years, but it depends on the weather and climate. Note that it has totally melted in the past, and refrozen again. There is a natural cycle of warm periods and ice ages. The only thing we can't have is the eternal continuation of the present climate. No matter what we do about man made global warming, some day the polar ice will all melt naturally. And some day there will be another ice age causing massive polar ice caps to cover half the world. It is just a matter of when, not if. Personally, I'll take a warm age with no polar ice over an ice age any day.
2006-12-04 03:50:44
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answer #2
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answered by campbelp2002 7
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The north pole is huge, there are mixed with three sources: 1. Ice 2. Land 3. Salt Water. Based upon your question: how long will the ice melt, is rather how we Humans abuse the plant, how the environment change, the magnetic field "shifts", and other things to cause the ice to melt including the south pole.
There is also the South Pole to take effect, as weal the north pole. Basically, it will take about 100 years or so to effect the phase-not to melt completely the north pole ice. Overall, it relay on human activity, and how evolution will pride upon Earth (the ice-age)....
The tem. in the North Pole varies; in winter it's -67 F, in summer is can reach 75 F. Also precipitation takes effect, snows increase the growth, sun shrinks the size, green house shrinks the size. Scientist assumes the entire ice cap to melt with in 100-150 years, research are taking place.
2006-12-04 03:18:58
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answer #3
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answered by Anonymous
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properly, some say that is a 50-50 chance of it melting this summer season (08) and that i have been gazing information superhighway cams on the north pole, so are you able to. they say the sea element will replace ALOT, yet my mom has a house on the bay of pensacola, Florida and she isn't considered a drastic replace like each and anybody is talking about. The north pole has been melting for years and years.... i'd be incorrect yet i imagine there is not component to freek out about. we were melting because the ice age, the earth is only doing this is element... google WEBCAMS on the north pole and word for your self or look on the link i'm gazing.
2016-11-30 03:13:15
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answer #4
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answered by lesure 4
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Long, but relatively to the "normal" melting rate, it is quite fast. And if it did melt, I am not sure most of us would be here because obviously many places would be flooded.
2006-12-04 03:03:56
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answer #5
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answered by webcop33 4
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Never
2006-12-04 03:34:27
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answer #6
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answered by JOHNNIE B 7
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erm.. i cant help with that, and i seriously dont wanna know
*runs away in denial*
2006-12-04 03:04:16
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answer #7
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answered by Anonymous
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you can help with a flame thrower
2006-12-04 03:07:27
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answer #8
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answered by Dreamweaver 5
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probably a pretty long time...DUH!
Xoxo
Audge*Paudge
2006-12-04 03:07:53
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answer #9
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answered by Audge*Paudge 1
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