Posted on 12/12/2006 8:13:39 AM PST by cogitator
The worrying shrinkage of Arctic sea ice could accelerate dramatically in coming decades, leaving the planet's most northerly ocean virtually devoid of ice in summer by 2040, according to a study published on Tuesday.
The paper, which appeared in the US journal Geophysical Research Letters, mainly points the finger at greenhouse-gas emissions.
It warned that if carbon pollution continues to increase at present rates, the Arctic's normal cycle of freezing and thawing faces catastrophic disruption.
A simulation run by scientists at the National Center for Atmospheric Research (NCAR) and Canada's McGill University predicted that the area covered by ice in September -- before new ice begins to form each year -- could shrink from about 5.9 million square kilometres to 1.9 million sq. kms. (2.3 million to 770,000 sq. miles) within a decade.
By 2040, "only a small amount of perennial sea ice" would remain along the north coasts of Greenland and Canada in summer, NCAR said in a press release.
In winter, ice thickness would be reduced from about 3.5 metres (about 12 feet) to less than a metre (three feet).
"We have already witnessed major losses in sea ice, but our research suggests that the decrease over the next few decades could be far more dramatic than anything that has happened so far," said NCAR scientist and lead author of the study, Marika Holland.
Greenhouse gases trap the Sun's heat, gradually forcing up Earth's surface temperature.
But several peripheral factors could also account for such a rapid meltdown.
Open water absorbs more sunlight than ice, accelerating the rate of warming and leading to more ice loss. In addition, global climate change is likely to drive warmer ocean currents into the Arctic region.
"This is a positive feedback loop with dramatic implications for the entire Arctic region," Holland said.
The shrinkage of the Arctic ice cap is viewed with alarm by scientists, as it appears to perturb important ocean currents elsewhere, notably the Gulf Stream, which gives western Europe its balmy climate.
It also threatens animals such as polar bears and seals that depend on ice -- as well as Inuits and other native peoples who hunt these animals and have to travel on thinner ice in this quest.
There are geopolitical implications, too, as Canada, Russia and the United States jockey to claim rights over transpolar passages that open up within their newly ice-free waters.
In September, European scientists unveiled satellite images from late August showing that perennial sea ice -- thick ice that is normally present year-round and is not affected by the Arctic summer -- had disappeared over an area bigger than the British Isles.
The study released Tuesday concludes that reduced rates of greenhouse gas emissions could slow the ice loss. "Our research indicates that society can still minimize the impacts on Artic ice," Holland said.
Sounds like Alaskan land may soon be more valuable.
I'm sorry, but didn't the entire ocean die like 5 years ago from all the aerosol spray we used in the '80s? I could have sworn there were a bunch of leftists and "scientific studies" proving how that was going to happen...
Global warming is NOT a hoax. It's real. What's NOT true is the spin that humans have anything to do with it. This planet has gone through icy cycles for millions of years. We just happen to be coming out of one since humans have been able to write thier observations down.
thier = their
I hope so. He's about one of the only ones out there with any sense.
If I promise to mail a bag of ice to the north poll would you send me $20?
Bookmark your thread and we'll revisit it in 2016.
Does it bother anyone else that every time dire predictions are made that they are always set out in terms of decades where a goodly portion of the people now here to read these forecasts will likely be dead when the real proof comes in?
Lately it seems that every published study is focused on a single element of the overall process and bolstered more by assumed feedback scenarios that have no counter influence in climatology but instead live entirely within the algorithmic realm of the computers used to create the prediction.
no no no, it's cows, cows are causing the increase of 1/2 a degree in the world's temperature.....
The UN says so:http://www.un.org/apps/news/story.asp?NewsID=20772&Cr=global&Cr1=warming
Waiting on the birth of some Alaskan orange groves.
;-)
The problem with these "imminent" disasters is that they commence at a snail's pace, And we probably won't live to see the disaster occur. Hope this helps.
Global warming due to man made green house gases is a hoax perpetrated by enviromentalists who tried to sell mass transit, smart growth, zero population growth, etc., but the people would not buy it so they are selling "you are all going to die"
Global warming is a fact, but whether man is causing it is in dispute and whether or not it is bad is also in dispute.
The earth has been warmer and colder in the past without any help from man.
Further, if it comes to an ice age or a hot period, a hot period is preferable. That is it will be better to be a few degrees warmer than colder.
Oh yeah, I forgot. That's the double whammy: environmentalists and anti-meat-itarians
Easier and cheaper to get Siberian oil to market. Sounds like global warming is a good thing.
My question: if it doesn't, and in fact perennial ice cover stays the same or even increases, will the global warming wonks shut up? They've made a a pretty strong prediction here about what will happen within a decade. So, if it doesn't...
The earth is always either cooling or warming, so whichever position you take you will have a 50/50 chance of being correct. The relevant question is, What is causing climate change? Anyone who thinks it is smoke from cigarettes or flatulence from cows is a certified whack-o.
B b b but Antarctic ice is building! I'm so confused.
There's already been a major reduction in the area covered by perennial sea ice. The prediction is for an acceleration, not just a continuation, of an observed trend. If in five years there is 30% less perennial sea ice cover, then we'll still have to see if there will be the predicted acceleration, but Arctic sea ice will still be melting away.
I was thinking maybe it was the polar bears and moose and elk perhaps up in the artic region causing the damage,
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