Climate change 'tipping points' imminent

[PredFan]

Odd...

What year did you pull that steaming pile from?

You just keep getting even dumber, walleyed. Please try to keep up. The article about Dr. Vines, that is being cited, quoted and very obviously linked to in the stuff you're quoting here, is from the year 2000, at a time when snowfall in Britain had been diminishing sharply for 15 years.

You're obviously too retarded to actually read all of the article that you denier nitwits keep citing as "proof" that all climate scientists must be idiots because one of them once carelessly said, 13 years ago and only referring to Britain, that snowfall will become "a very rare and exciting event", which you nutjobs have been misled into misinterpreting to mean that all climate scientists everywhere somehow believe "there will be no snow anytime anywhere almost immediately". Of course, the other statement he made, you ignore: "Heavy snow will return occasionally, says Dr Viner." The other piece of that article, that you deniers often stupidly mis-attribute to Dr. Viner, is the poorly written and sensationalistic headline that was actually written by the reporter writing the article and which stated: "Snowfalls are now just a thing of the past". Cherry-picking the quotes you use out of that article is just another example of your denier cult's moronic effort to smear science and scientists because you don't want to hear what they are telling the world about the reality and dangers of anthropogenic global warming.

Someone else quotes another part of that article that talks about how it had gotten so warm and snow-free in Britain at that time that the Fen skating had to move to indoor skating rinks and you object by citing contemporary outdoor Fen skating as if that has anything to do with what was happening 13 years ago. You are so out of touch and clueless.

You deniers ignore all the parts of that article that don't support your propaganda memes. Like the opening paragraphs that give the article some rational context.

"Britain's winter ends tomorrow with further indications of a striking environmental change: snow is starting to disappear from our lives. Sledges, snowmen, snowballs and the excitement of waking to find that the stuff has settled outside are all a rapidly diminishing part of Britain's culture, as warmer winters - which scientists are attributing to global climate change - produce not only fewer white Christmases, but fewer white Januaries and Februaries.

The first two months of 2000 were virtually free of significant snowfall in much of lowland Britain, and December brought only moderate snowfall in the South-east. It is the continuation of a trend that has been increasingly visible in the past 15 years: in the south of England, for instance, from 1970 to 1995 snow and sleet fell for an average of 3.7 days, while from 1988 to 1995 the average was 0.7 days. London's last substantial snowfall was in February 1991.
(source)

There are reasons why the winters became harsher with increased snowfall in a number of the years after the year 2000 but it's late so I'll have to get back to that at a later time.

Sure, take some time, figure out how to spin your way out of this, then get back to us.

 

[RollingThunder]

1975: The total freezing over of the planet is imminent!

Denier cult myth. Most scientists even then thought warming was more likely.


The ozone layer was, in fact, being thinned by chlorofluorocarbons and a hole in the ozone appeared over Antarctica and the incidence of melanomas and skin cancers increased, particularly in Australia, but nobody was predicting the "imminent complete destruction of the Ozone Layer". So, just another denier cult myth/exaggeration/propaganda meme to deceive the gullible, ignorant, anti-science rightwingnuts like you, ProdFcked.


True. The polar ice caps are melting now. The Arctic ice cap is melting away far more quickly than Antarctica but both are losing ice mass. However, no scientists were predicting in 1995 that they would melt as much as they actually have this soon.


Denier cult myth and complete nonsense. Jeez, you're gullible, ProdFcked.

2013: The Climate Change tipping point is imminent!

True. Several climate change tipping points are either imminent or have already been passed. Arctic feedback is one and that happens when the icy white reflective ice cover over the ocean melts and the dark, energy absorbing ocean surface starts warming even faster, thus melting more of the ice cover. Arctic methane release is another and that is already starting to happen as the permafrost melts and the sea bottom methane clathrates destabilize and methane gas, which is another greenhouse gas that is over 30 times more powerful than CO2, goes into the air and causes even faster warming. The Arctic is now warming up eight times faster than the rest of the planet.

Actually, the scientists DID say that we would have what amounted to a nuclear winter that would last years maybe even decades. I know that as a fact. I was there, and I believed it then.

No, ProdFcked, no scientist ever said any such nonsense like "we would have what amounted to a nuclear winter" when, in the 70s, they were researching the cooling trend caused by pollution. You're such a delusional retard, you'll believe any fraudulent bullshit your puppet masters feed to you.

And scientists DID say that by 2010 we would have winters without snow. That is a fact.

Just one climate scientist, in 2000, talking exclusively about Britain after there had been rapidly diminishing snow in winter for 15 years, predicted that snowfalls in Britain would become rare, and he gave no date. You're so stupid you don't know the difference between "a fact" and your moronic delusions. You make absurd claims that you can't back up with any actual evidence.

 

[flacaltenn]

Denier cult myth. Most scientists even then thought warming was more likely.


The ozone layer was, in fact, being thinned by chlorofluorocarbons and a hole in the ozone appeared over Antarctica and the incidence of melanomas and skin cancers increased, particularly in Australia, but nobody was predicting the "imminent complete destruction of the Ozone Layer". So, just another denier cult myth/exaggeration/propaganda meme to deceive the gullible, ignorant, anti-science rightwingnuts like you, ProdFcked.


True. The polar ice caps are melting now. The Arctic ice cap is melting away far more quickly than Antarctica but both are losing ice mass. However, no scientists were predicting in 1995 that they would melt as much as they actually have this soon.


Denier cult myth and complete nonsense. Jeez, you're gullible, ProdFcked.


True. Several climate change tipping points are either imminent or have already been passed. Arctic feedback is one and that happens when the icy white reflective ice cover over the ocean melts and the dark, energy absorbing ocean surface starts warming even faster, thus melting more of the ice cover. Arctic methane release is another and that is already starting to happen as the permafrost melts and the sea bottom methane clathrates destabilize and methane gas, which is another greenhouse gas that is over 30 times more powerful than CO2, goes into the air and causes even faster warming. The Arctic is now warming up eight times faster than the rest of the planet.

Actually, the scientists DID say that we would have what amounted to a nuclear winter that would last years maybe even decades. I know that as a fact. I was there, and I believed it then.

No, ProdFcked, no scientist ever said any such nonsense like "we would have what amounted to a nuclear winter" when, in the 70s, they were researching the cooling trend caused by pollution. You're such a delusional retard, you'll believe any fraudulent bullshit your puppet masters feed to you.

And scientists DID say that by 2010 we would have winters without snow. That is a fact.

Just one climate scientist, in 2000, talking exclusively about Britain after there had been rapidly diminishing snow in winter for 15 years, predicted that snowfalls in Britain would become rare, and he gave no date. You're so stupid you don't know the difference between "a fact" and your moronic delusions. You make absurd claims that you can't back up with any actual evidence.

Viner said "in a few years".. What is a few years? I expect most people would say less than 10, certainly less than 14.... BZSZZZZZT..

And as I posted in another thread -- the IPCC was also hawking REDUCED snowfall circa 2000 as well..

 

[RollingThunder]

Actually, the scientists DID say that we would have what amounted to a nuclear winter that would last years maybe even decades. I know that as a fact. I was there, and I believed it then.

No, ProdFcked, no scientist ever said any such nonsense like "we would have what amounted to a nuclear winter" when, in the 70s, they were researching the cooling trend caused by pollution. You're such a delusional retard, you'll believe any fraudulent bullshit your puppet masters feed to you.

And scientists DID say that by 2010 we would have winters without snow. That is a fact.

Just one climate scientist, in 2000, talking exclusively about Britain after there had been rapidly diminishing snow in winter for 15 years, predicted that snowfalls in Britain would become rare, and he gave no date. You're so stupid you don't know the difference between "a fact" and your moronic delusions. You make absurd claims that you can't back up with any actual evidence.

Viner said "in a few years".. What is a few years? I expect most people would say less than 10, certainly less than 14.... BZSZZZZZT..

And as I posted in another thread -- the IPCC was also hawking REDUCED snowfall circa 2000 as well..

LOLOLOLOL.....it is hilarious watching you trying futilely to grasp at imaginary straws as your propaganda memes get debunked, fecalhead.

Meanwhile....

US Navy predicts summer ice free Arctic by 2016
Is conventional modelling out of pace with speed and abruptness of global warming?
The Guardian
Nafeez Ahmed
9 December 2013
(excerpts)
An ongoing US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections. The project, based out of the US Naval Postgraduate School's Department of Oceanography, uses complex modelling techniques that make its projections more accurate than others. A paper by principal investigator Professor Wieslaw Maslowski in the Annual Review of Earth and Planetary Sciences sets out some of the findings so far of the research project: "Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."

The paper is highly critical of global climate models (GCM) and even the majority of regional models, noting that "many Arctic climatic processes that are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs." According to the US Department of Energy describing the project's development of the Regional Arctic System Model (RASM): "Given that the Arctic is warming faster than the rest of the globe, understanding the processes and feedbacks of this polar amplification is a top priority. In addition, Arctic glaciers and the Greenland Ice Sheet are expected to change significantly and contribute to sea level rise in the coming decades." Such Arctic changes "could have significant ramifications for global sea level, the ocean thermohaline circulation and heat budget, ecosystems, native communities, natural resource exploration, and commercial transportation."

 

[westwall]

No, ProdFcked, no scientist ever said any such nonsense like "we would have what amounted to a nuclear winter" when, in the 70s, they were researching the cooling trend caused by pollution. You're such a delusional retard, you'll believe any fraudulent bullshit your puppet masters feed to you.




Just one climate scientist, in 2000, talking exclusively about Britain after there had been rapidly diminishing snow in winter for 15 years, predicted that snowfalls in Britain would become rare, and he gave no date. You're so stupid you don't know the difference between "a fact" and your moronic delusions. You make absurd claims that you can't back up with any actual evidence.

Viner said "in a few years".. What is a few years? I expect most people would say less than 10, certainly less than 14.... BZSZZZZZT..

And as I posted in another thread -- the IPCC was also hawking REDUCED snowfall circa 2000 as well..

LOLOLOLOL.....it is hilarious watching you trying futilely to grasp at imaginary straws as your propaganda memes get debunked, fecalhead.

Meanwhile....

US Navy predicts summer ice free Arctic by 2016
Is conventional modelling out of pace with speed and abruptness of global warming?
The Guardian
Nafeez Ahmed
9 December 2013
(excerpts)
An ongoing US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections. The project, based out of the US Naval Postgraduate School's Department of Oceanography, uses complex modelling techniques that make its projections more accurate than others. A paper by principal investigator Professor Wieslaw Maslowski in the Annual Review of Earth and Planetary Sciences sets out some of the findings so far of the research project: "Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."

The paper is highly critical of global climate models (GCM) and even the majority of regional models, noting that "many Arctic climatic processes that are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs." According to the US Department of Energy describing the project's development of the Regional Arctic System Model (RASM): "Given that the Arctic is warming faster than the rest of the globe, understanding the processes and feedbacks of this polar amplification is a top priority. In addition, Arctic glaciers and the Greenland Ice Sheet are expected to change significantly and contribute to sea level rise in the coming decades." Such Arctic changes "could have significant ramifications for global sea level, the ocean thermohaline circulation and heat budget, ecosystems, native communities, natural resource exploration, and commercial transportation."

Oh goody! The doofus's took the bait! The article explains how all the current crop of GCM's are crap then gives us this new wonderful model to compare with observations. And, what's even better is they predicted a near term result...one that we will be able to see for ourselves!

This is the end of the beginning gents! This guy has set the AGW clowns up for an epic fail that will really crush them!

 

[Old Rocks]

Viner said "in a few years".. What is a few years? I expect most people would say less than 10, certainly less than 14.... BZSZZZZZT..

And as I posted in another thread -- the IPCC was also hawking REDUCED snowfall circa 2000 as well..

LOLOLOLOL.....it is hilarious watching you trying futilely to grasp at imaginary straws as your propaganda memes get debunked, fecalhead.

Meanwhile....

US Navy predicts summer ice free Arctic by 2016
Is conventional modelling out of pace with speed and abruptness of global warming?
The Guardian
Nafeez Ahmed
9 December 2013
(excerpts)
An ongoing US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections. The project, based out of the US Naval Postgraduate School's Department of Oceanography, uses complex modelling techniques that make its projections more accurate than others. A paper by principal investigator Professor Wieslaw Maslowski in the Annual Review of Earth and Planetary Sciences sets out some of the findings so far of the research project: "Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."

The paper is highly critical of global climate models (GCM) and even the majority of regional models, noting that "many Arctic climatic processes that are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs." According to the US Department of Energy describing the project's development of the Regional Arctic System Model (RASM): "Given that the Arctic is warming faster than the rest of the globe, understanding the processes and feedbacks of this polar amplification is a top priority. In addition, Arctic glaciers and the Greenland Ice Sheet are expected to change significantly and contribute to sea level rise in the coming decades." Such Arctic changes "could have significant ramifications for global sea level, the ocean thermohaline circulation and heat budget, ecosystems, native communities, natural resource exploration, and commercial transportation."

Oh goody! The doofus's took the bait! The article explains how all the current crop of GCM's are crap then gives us this new wonderful model to compare with observations. And, what's even better is they predicted a near term result...one that we will be able to see for ourselves!

This is the end of the beginning gents! This guy has set the AGW clowns up for an epic fail that will really crush them!

UAH v5.6 Global Temperature Update for Nov. 2013: +0.19 deg. C « Roy Spencer, PhD

November 2013 has a 0.19 rating from Dr. Spencer. That is roughly mid-point since 1998. And above all but four months prior to 1998. And it looks as if 2013 will come in as seventh warmest on record. Seems if we are going to cool, sometime some of these years should come in at 70th warmest. But that is not going to happen. And when we get the next strong El Nino, another new record will be set.

 

[ScienceRocks]

Old rocks, 4 years ago I thought a moderate enso would = record by now. I am quite amazed at how we're starting to get 7-9th place that we'd otherwise be within the top 5, five years ago.

 

[westwall]

LOLOLOLOL.....it is hilarious watching you trying futilely to grasp at imaginary straws as your propaganda memes get debunked, fecalhead.

Meanwhile....

US Navy predicts summer ice free Arctic by 2016
Is conventional modelling out of pace with speed and abruptness of global warming?
The Guardian
Nafeez Ahmed
9 December 2013
(excerpts)
An ongoing US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections. The project, based out of the US Naval Postgraduate School's Department of Oceanography, uses complex modelling techniques that make its projections more accurate than others. A paper by principal investigator Professor Wieslaw Maslowski in the Annual Review of Earth and Planetary Sciences sets out some of the findings so far of the research project: "Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."

The paper is highly critical of global climate models (GCM) and even the majority of regional models, noting that "many Arctic climatic processes that are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs." According to the US Department of Energy describing the project's development of the Regional Arctic System Model (RASM): "Given that the Arctic is warming faster than the rest of the globe, understanding the processes and feedbacks of this polar amplification is a top priority. In addition, Arctic glaciers and the Greenland Ice Sheet are expected to change significantly and contribute to sea level rise in the coming decades." Such Arctic changes "could have significant ramifications for global sea level, the ocean thermohaline circulation and heat budget, ecosystems, native communities, natural resource exploration, and commercial transportation."

Oh goody! The doofus's took the bait! The article explains how all the current crop of GCM's are crap then gives us this new wonderful model to compare with observations. And, what's even better is they predicted a near term result...one that we will be able to see for ourselves!

This is the end of the beginning gents! This guy has set the AGW clowns up for an epic fail that will really crush them!

UAH v5.6 Global Temperature Update for Nov. 2013: +0.19 deg. C « Roy Spencer, PhD

November 2013 has a 0.19 rating from Dr. Spencer. That is roughly mid-point since 1998. And above all but four months prior to 1998. And it looks as if 2013 will come in as seventh warmest on record. Seems if we are going to cool, sometime some of these years should come in at 70th warmest. But that is not going to happen. And when we get the next strong El Nino, another new record will be set.

Here's your other favorite "canary in the coal mine". Remember them olfraud? The two poles were the areas MOST likely to suffer from the effects of global warming. Here's the reality....

 

[flacaltenn]

WestWall nailed it.. Whatever "new complex sophisticated" modeling techniques these jokers are applying -- THIS quote makes it seem like that tool is a ruler or other straightedge..

"Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."

First off -- I'm not hearing how MORE ACCURATE modeling squares with the remaining High Uncertainty. And secondly +/- 3 yrs seems pretty specific to me. They laid down the ruler and made the odds. THIRD -- it twerks my buttons when I see a "complex IMPROVED model" require a STARTING POINT that is specific to Oct-Nov 2007 !!!!!!!!!!!!!!!!!!!!!!!!!!! (sounds more like a ruler all the time)

GREAT !!! They acknowledge the GCMs and previous models are crap -- toss a few darts and retire early.. GOOD JOB TinkerBelle ---- I love this one... Find us some more like that..

PS... It's already 2014 for petes sakes. They are making their prediction out --- 2 years +/- 3yrs?????

LOLOLOLOLOLOLOLOLOLOLOL Why by george --- IT MIGHT HAVE ALREADY OCCURED !!!!!!!

 

[flacaltenn]

The great minds at the Naval PostGraduate School are probably cringing as they read this crap..
Just like the embarrassment in NASA over THEIR "climate kook" departments.

 

[Abraham3]

Try this one. Open your mind and take the 3rd dimension into account. IOW, get real.

Note the bottom of the vertical scale. ZERO. And that's not an anomaly. That the absolute, total bloody ice volume.

 

[Abraham3]

Here's another one. I bet even you can see when this might first hit ZERO.

 

[RollingThunder]

US Navy predicts summer ice free Arctic by 2016
Is conventional modelling out of pace with speed and abruptness of global warming?
The Guardian
Nafeez Ahmed
9 December 2013
(excerpts)
An ongoing US Department of Energy-backed research project led by a US Navy scientist predicts that the Arctic could lose its summer sea ice cover as early as 2016 - 84 years ahead of conventional model projections. The project, based out of the US Naval Postgraduate School's Department of Oceanography, uses complex modelling techniques that make its projections more accurate than others. A paper by principal investigator Professor Wieslaw Maslowski in the Annual Review of Earth and Planetary Sciences sets out some of the findings so far of the research project: "Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3, one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover."

The paper is highly critical of global climate models (GCM) and even the majority of regional models, noting that "many Arctic climatic processes that are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs." According to the US Department of Energy describing the project's development of the Regional Arctic System Model (RASM): "Given that the Arctic is warming faster than the rest of the globe, understanding the processes and feedbacks of this polar amplification is a top priority. In addition, Arctic glaciers and the Greenland Ice Sheet are expected to change significantly and contribute to sea level rise in the coming decades." Such Arctic changes "could have significant ramifications for global sea level, the ocean thermohaline circulation and heat budget, ecosystems, native communities, natural resource exploration, and commercial transportation."

The article explains how all the current crop of GCM's are crap....

They acknowledge the GCMs and previous models are crap -

Retards like you two always see what you want to see, no matter what is actually there, partly because you're just too stupid to comprehend what is being explained, and partly because you're so damn brainwashed. The newspaper reporter who wrote this article that I cited was the one who said that the paper is "critical of global climate models" (he also titled the article: "Is conventional modelling out of pace with speed and abruptness of global warming?", which should have given you a clue), but the paper itself doesn't even suggest that the global climate models "are crap", as you two denier cult retards need to believe to sustain your crackpot myths. It just indicates that certain aspects of the models need to be improved to better reflect some of the complex interactions and feedbacks in the Arctic. As that article reports, the study specifically states that ""many Arctic climatic processes are omitted from, or poorly represented in, most current-generation GCMs" which "do not account for important feedbacks among various system components." There is therefore "a great need for improved understanding and model representation of physical processes and interactions specific to polar regions that currently might not be fully accounted for or are missing in GCMs."....."Given that the Arctic is warming faster than the rest of the globe, understanding the processes and feedbacks of this polar amplification is a top priority."

If you two had had at least the integrity and intellectual honesty of a cocker spaniel, you'd have followed the link to the article I quoted and read the rest of it and discovered that you're full of shit about it's conclusions. Here's the link to the actual entire original scientific paper, retards, and some relevant excerpts. Try and find anything in it that even suggests that the scientists writing it think that all the GCMs "are crap" or that your demented denier cult myths have any basis in reality.

The Future of Arctic Sea Ice
Annual Review of Earth and Planetary Sciences
Vol. 40: 625-654 (Volume publication date May 2012)
First published online as a Review in Advance on March 8, 2012
DOI: 10.1146/annurev-earth-042711-105345
Wieslaw Maslowski,1 Jaclyn Clement Kinney,1 Matthew Higgins,2 and Andrew Roberts1
1Department of Oceanography, Naval Postgraduate School, Monterey, California 93943; email: [email protected], [email protected], [email protected]
2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309; email: [email protected]
FULL-TEXT| PDF (3681 KB)
(excerpts]

ABSTRACT
Arctic sea ice is a key indicator of the state of global climate because of both its sensitivity to warming and its role in amplifying climate change. Accelerated melting of the perennial sea ice cover has occurred since the late 1990s, which is important to the pan-Arctic region, through effects on atmospheric and oceanic circulations, the Greenland ice sheet, snow cover, permafrost, and vegetation. Such changes could have significant ramifications for global sea level, the ocean thermohaline circulation, native coastal communities, and commercial activities, as well as effects on the global surface energy and moisture budgets, atmospheric and oceanic circulations, and geosphere-biosphere feedbacks. However, a system-level understanding of critical Arctic processes and feedbacks is still lacking. To better understand the past and present states and estimate future trajectories of Arctic sea ice and climate, we argue that it is critical to advance hierarchical regional climate modeling and coordinate it with the design of an integrated Arctic observing system to constrain models.

Over the past decade, various studies have attempted to estimate the future trajectory of Arctic climate and have proposed a wide range of projections of seasonal Arctic sea ice cover. We summarize most of these projections below to emphasize that more work is needed to minimize confusion, identify uncertainty, and advance the prediction of Arctic sea ice change. GCMs used in the Arctic Climate Impact Assessment studies on average predict more than a 50% reduction of summer sea ice cover in the Arctic Ocean by the end of this century (ACIA 2004). GCMs participating in the World Climate Research Programme (WCRP) CMIP2 predict a little over 10% decrease of sea ice concentration in response to doubling of CO2 (Hu et al. 2004). Models participating in the Intergovernmental Panel for Climate Change Fourth Assessment Report (IPCC AR4) and in CMIP3 suggest the reduction of sea ice cover to an almost ice-free Arctic Ocean in summer by the end of this century (Johannessen et al. 2004, Zhang & Walsh 2006), and by 2040 in the most extreme predictions (e.g., Holland et al. 2006). Unfortunately, the majority of GCMs, including those participating in the IPCC AR4, have not been able to adequately reproduce observed multidecadal sea ice variability and trends in the pan-Arctic region (Stroeve et al. 2007). The ensemble multimodel mean trend in September Arctic sea ice extent from 1953 to 2006 is too conservative; it is approximately 30 years behind the observed trend. Using a subset of better-performing IPCC AR4 GCMs to provide improved regional projections of Arctic sea ice, Overland & Wang (2007) projected over 40% loss of sea ice area over the marginal seas of the Arctic Ocean by 2050 in summer. In a following study, using extended observations of the Arctic sea ice minimum through 2008 as an initial point for interpolating results from six IPCC AR4 models, Wang & Overland (2009) projected a nearly sea ice–free Arctic Ocean in September by 2037. Another independent, yet nonanalytical, estimate by Stroeve et al. (2008) brings this projection even closer.

 

[Abraham3]

30 years behind the trend?!?!? Oh those flawe-ed models ! ! !

;-)

 

[Kosh]

The AGW propaganda just keeps on coming!

 

[Abraham3]

Why do you think it's propaganda?

You really seem to be making unsubstantiated assertions a habit.

 

[ScienceRocks]

Why do you think it's propaganda?

You really seem to be making unsubstantiated assertions a habit.

Simply that he only looks at the graph after 2000 and assumes that all the energy is going into the atmosphere.

 

[Abraham3]

Hold up a minute. Let the man answer the question himself.

 

[Kosh]

Why do you think it's propaganda?

You really seem to be making unsubstantiated assertions a habit.

Did you say that looking into a mirror?

It has been proven time and time again that AGW is bunk.

Only the loyal AGW church members and scribes are still trying to make it relevant as it is their religion to do so.

 

[Abraham3]

Why do you think it's propaganda?

You really seem to be making unsubstantiated assertions a habit.

Did you say that looking into a mirror?

It has been proven time and time again that AGW is bunk.

Only the loyal AGW church members and scribes are still trying to make it relevant as it is their religion to do so.

Please explain to us why YOU believe it to be bunk.