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.
Bad recollection. It was 10 F maximum (6 Centigrade), and even the scientists who generated that estimate took pains to point out that it was the true bound and a couple of basic assumptions had to be modified to get there. According to a story I read recently, the next IPCC report won't change the range of estimates for 2100, but they will indicate there is now greater confidence that a temperature increase in that range will occur. One article (just found, cuz I lahks to check my sahces -- attempting a textual Al Gore accent) indicates near-virtual certainty of a 1.5 C rise by 2100.
There's a prediction for you. Who's going to tell my grandchildren if it was right or not?
You probably have a very good database of predictions.
Not really. I've tried to keep track of the global temperature projections, primarily.
Yes, I happen to know that. What I was indicating is that it isn't following in lockstep with what the other 95% of the Earth is doing, climate-wise.
You shouldn't be dishonest when you characterize Inhofes views. He acknowledges that the Earth has been warming since the Little Ice Age which is a good thing both substantively and politically.
Inhofe states clearly that he thinks anthropogenic global warming is a hoax. He's wrong.
I could just as easily assume all those changes were due from methane gas from cows and match the curve. Or you could put in World Series victories by the Yankees and fit the curve. You could put in thousands of factors that have increased over the years and make the curve match. Computer models don't prove anything.
LOL, right. Those scientists knew the highend number was completely bogus, but yet news story after news story reported the highend numbers as did IPCC reports. They took no pains in clarifying what that number meant. It was a bogus number that assumed that the few negative feedback mechanisms they did consider, were removed.
Show us a quote in context. The quotes I have seen from Inhofes which talks about a hoax, is referring to catastrophic global warming.
Sigh. Never tell me there is no support for something that I know something about.
What does the lag of CO2 behind temperature in ice cores tell us about global warming?
Water Vapour, CO2 and Insolation over the Last Glacial-Interglacial Cycles
Feedback Loops in Global Climate Change Point to a Very Hot 21st Century
What Caused Glacial-Interglacial CO2 change? (This is a Powerpoint presentation, so good that I saved it after Google found it for me).
Ice-driven CO2 feedback on ice volume
CO2 Lags, Not Leads (countering a common skeptical argument)
I'll bet you a FR recantation of your statement above that they will not make such a clear prediction with regard to cloud feedback effects. If they do, I will publically state on FR that your statement was accurate and that I was wrong.
Unlike predictions of the global temperature for 2100, in this case we only have to wait until February. Game?
Most analyses attribute some of the cooling to sulfur aerosols from the war and post-war industrialization (into the 70s, when the Clean Air Act started to kick in). Remember that the 1930s was a hot decade (Dust Bowl!) and the slight mid-century cooling commenced at the end of the 1930s.
I can't quantify an anser to that question. Based on reading a lot of what the various scientists say, I would characterize their position as: many of them don't want to predict catastrophe, but a lot of them are quite concerned about the possibility of it. And there is a general agreement that no action at all increases the likelihood of dangerous climate change.
Got to go. But will look at that stuff later.
"As chairman of the Committee on Environment and Public Works, I have a profound responsibility, because the decisions of the committee have wide-reaching impacts, influencing the health and security of every American." (in context enough?)
"For these reasons I would like to discuss an important body of scientific research that refutes the anthropogenic theory of catastrophic global warming. I believe this research offers compelling proof that human activities have little impact on climate."
and
"I would submit, furthermore, that not only is there a debate, but the debate is shifting away from those who subscribe to global warming alarmism. After studying the issue over the last several years, I believe that the balance of the evidence offers strong proof that natural variability is the overwhelming factor influencing climate."
Now, it is true that he frequently precedes "global warming" with "catastrophic". But for him to say that there is "compelling proof that human activities have little impact on climate" is a basic denial of the scientific conclusion that human activities have a substantial effect on climate. Correct?
I would also submit that prefacing "global warming" with "catastrophic" gives him a clever politician's way out, for if it ever becomes clear even to him that human activities are having a substantial effect on climate, then he can retreat and say "look, I wasn't talking about global warming, I was only talking about catastrophic global warming". His statements above make it clear that his view is that human activities are a very minor player in the climate game.
Source?
This source claims, on balance, an apparent net loss for Greenland ice:
It is true that both Greenland and Antarctica have gained mass, but only at the high elevations in their interior. This is because of increased snowfall, which even though it may seem counterintuitive, is actually expected under warmer conditions. However, both have been losing ice at the coast at increasing rates in recent years. In Greenland, it is becoming apparent that there is a net loss of ice. In Antarctica, the data are inconclusive, although the most recent results point to a loss. Under continued warming conditions, a net loss of ice is assured and rising sea levels would follow.
http://nsidc.org/news/press/20060706_goremoviefaq.html
According to the NSIDC (National Snow and Ice Data Center), it looks like Greenland probably has a net loss of ice.
and monkeys could fly out of Madonna's, but Garth, that's not polite!
Sorry if the truth hurts Wayne.
"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."
Agreed with all except that as the polar caps melt the sea level rises, making trillions of dollars of oceanfront property unlivable. Mankind will still go on of course...
Maybe not, but it is bull methane in a Hurricane.
It's like an Astronaut rocking forward in his seat to make the Shuttle go faster.
It is worse than a hoax, because at least a hoax is intentionally believable.
Anyone that feels that humanity should be concerned with Global Warming might just as well be concerned with the Sun going nova.
Isn't that Tipper calling you, Al?
If it floods Santa Monica, this could be a good thing.
"This [cooling] trend will reduce agricultural productivity for the rest of the century"
- Peter Gwynne, Newsweek 1976
"This cooling has already killed hundereds of thousands of people. If it continues and no strong action is taken, it will cause world famine, world chaos and world war, and this could all come about before the year 2000."
- Lowell Ponte "The Cooling", 1976
If you ask me, it'd be a little short of disastrous for us to discover a source of clean, cheap, abundant energy because of what we would do with it. We ought to be looking for energy sources that are adequate for our needs, but that won't give us the excesses of concentrated energy with which we could do mischief to the earth or to each other.
- Amory Lovins in The Mother Earth - Plowboy Interview, Nov/Dec 1977, p. 22
Ice happens. Then it melts.
Are there no asteroids lurking out there that might strike earth a deathblow, or has that threat been calculated out of existence for the next 76,000 years?
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