24 Feb 2009

Tracking the Fallout of the Arctic’s Vanishing Sea Ice

Julienne Stroeve, a research scientist at the National Snow and Ice Data Center at the University of Colorado, has been closely monitoring the rapid loss of sea ice in the Arctic. In an interview with Yale Environment 360, she explains how the repercussions of that disappearance will be felt throughout the far north and, eventually, the entire

The precipitous loss of Arctic sea ice has been well documented — and well publicized. Now, an increasing number of scientists are turning their attention to a vital question: Once the Arctic Ocean’s summer sea ice disappears — which many scientists say could happen in roughly 20 years — what comes next?

Julienne Stroeve and her colleagues at the National Snow and Ice Data Center are just beginning to study the ripple effects of the rapid shrinking and eventual seasonal disappearance of what Stroeve calls “the air conditioner of the Northern Hemisphere.” What they have already discovered has shown that the changes will be profound. In a recent study, published in the journal The Cryosphere, Stroeve and her colleagues showed that in areas where summer sea ice already has disappeared, autumn air temperatures have been more than 5 degrees F warmer than the long-term average, in large part because the exposed ocean absorbs far more heat than sea ice.

When contemplating the effects of global warming, scientists have always
Julienne Stroeve
been concerned about so-called “positive feedbacks”: Rising temperatures cause sea ice to melt, the dark water absorbs much more heat than the white surface of the ice, and that in turn warms up the ocean and the air even more, causing more ice to melt — all of it creating a tightening spiral of increased thawing and warming. Stroeve and others call this “Arctic amplification.” No matter what you call it, scientists concerned about climate instability don’t see much positive in “positive feedbacks” — it is a vicious cycle that is hard to break.

In an interview with Yale Environment 360 senior editor Fen Montaigne, Stroeve discussed what may lie ahead if the Arctic’s summer sea ice melts away, from further warming of Arctic land masses to the unpredictable impact on the climate of the Northern Hemisphere.

Yale Environment 360: You and your colleagues have done some very important work about how the loss of sea ice in the Arctic is beginning to have some significant impacts on regional climate. I wondered if you could give us a little background on the extent of Arctic sea ice loss, and what you have found through your research about how this is beginning to have an amplifying effect on the Arctic?

Julienne Stroeve: Well, what we have been observing, at least over the last 30 years — and probably over the last 50 years if we look at some earlier records that aren’t based on satellite data — is that the Arctic has been losing its sea ice cover basically in all the calendar months. But the ice
Listen to the full interview (21 min.)
losses are largest in summertime, particularly at the end of the melt season when you reach your minimum extent in September. Basically, over the last few years, ever since 2002, we’ve had one pronounced record minimum after another, and it has caused a pretty strong acceleration of the downward trend in the Arctic sea ice cover in September. The trend is almost -12 percent per decade right now.

What we have been noticing is that because we now have these large expanses of open water areas in September, that when the sun starts going down and the air temperatures get cool enough to start causing sea ice to re-form again for the winter, before the ocean can re-freeze it has to release all that heat back into the atmosphere. This is heat that the ocean absorbed because now instead of being covered by ice it is being exposed to the sun during the summertime. That is what we term Arctic amplification, the idea that the warming in the Arctic is going to be greater than anywhere else on the planet, largely because of this feedback effect, because when you melt away the snow and the ice you expose these darker surfaces — like the oceans or the land — which then absorb that heat, and that heat gets re-released.

We did a study where we looked at changes in atmospheric temperature in the autumn season, related to these recent extreme ice losses that we’ve been seeing in September. What we’re finding is that there is a very strong warming signal with temperatures over the Arctic Ocean, about 3 degrees C (5.4 F), on average, warmer than normal, during these last 5 years compared to the longer term record, which started in 1979. This warming is centralized over the Arctic Ocean where you’re losing the ice, but it can also spread toward the land areas by atmospheric circulation, and then cause more warming of land surface temperatures as well.

e360: And that was from 2003 to 2007, when you were detecting these much higher temperatures than the long-term average?

Stroeve: That’s right. And we’ve known that this was going to happen, looking at climate model simulations because they all show this kind of amplified warming in the Arctic. But it’s just happening sooner (than predicted) right now.

e360: I want to jump back and ask one question about the loss. You said it’s about 12 percent per decade. I take it from both the satellite records, which go back 30 years, and previous records, that a rough estimate of the overall extent of summer Arctic sea ice is that it is now roughly at 40 percent to 50 percent of what it was 50 or 60 years ago?

Stroeve: Right. We have about 40 percent to 50 percent less of the Arctic Ocean surface area covered by ice now than what we used to have 40 or 50 years ago. That’s a significant drop.

e360: Do you have any data about how much Arctic Ocean water temperatures seem to be going up in the most recent decade or two?

Stroeve: There’s a combination of a few different effects there. One is more inflow of warm waters into the Arctic, through the Bering Strait, for example, which seems to be then circulating around the Arctic, and
We’re basically about 30 years ahead right now of where the models say we should be, in terms of how quickly the ice is declining.
resulting in some warmer temperatures and perhaps more melting of the ice from below. And then there’s also the effect that you get just from exposing the ocean now to the sun and letting it absorb all that solar energy, because the albedo — or the amount of solar energy that gets reflected back by the water — is very small. It absorbs almost 93 percent of all the incoming solar radiation, whereas the ice, if it is snow covered, will reflect about 80 percent of that incoming solar energy back out to space. The presence of ice definitely helps keeps things much cooler.

e360: Can you say what the earlier projections were for loss of summer sea ice cover in the Arctic, and when you might see a generally ice-free Arctic Ocean?

Stroeve: We did a study a couple of years ago where we looked at a comparison between the observed record that is coming from the satellite data and then the climate models that were used in the latest IPCC

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[Intergovernmental Panel on Climate Change] report. Basically, all of those models are consistent in that the ice cover has been going down over the whole period of observations. But even so, when you run these models out into the future and you do business-as-usual scenarios of greenhouse gas emissions, basically these models will show the ice disappearing entirely in the summertime sometime between 2050 to sometime beyond 2100. We’re basically about 30 years ahead right now of where the models say we should be, in terms of how quickly the ice is declining.

And so, maybe an ice-free Arctic Ocean might be realized as early as 2030. There are some people who think it may happen even sooner, that the ocean is contributing a lot more to the melting of the ice than than we have been realizing, and that the volume of the ice in the Arctic is actually at an all-time record low.

e360: When you talk about the volume, of course, you are talking about both extent and thickness. Could you just briefly explain how open water absorbing more heat has an impact on how hard or thick ice is then going to re-freeze? I would think the ice just keeps getting thinner and thinner.

Stroeve: Well, certainly, by delaying the melt season, if it takes longer for the ocean to re-freeze, then you have a shorter growing period for the ice to thicken. But natural variability has also been playing a big role in helping to reduce the ice thickness in the Arctic — in the mid-1990s there was a very strong Arctic oscillation weather pattern that helped to get rid of some of that older, thicker ice, leaving behind much younger, and therefore much thinner, ice in the Arctic. And so, basically we don’t seem to have these very thick stores of ice like we used to that help stabilize the ice cover.

Say you had a really warm summer and you had conditions very favorable for melting. If you had ice conditions like you had in the 1970s, where you had much thicker ice, and a larger fraction of the Arctic Ocean was covered by thick ice, you may have a lot of melt happening and you may have a large volume loss in the total ice cover, but you wouldn’t really see that reflected in extent changes because the ice is so thick. But you can imagine as you get down to a much thinner ice cover, now we are at this point where the Arctic Ocean is covered by much thinner ice, so then when you have an usually warm summer, all of a sudden you melt out large areas of the ice cover and you have these big open water areas forming.

e360: And, I take it that the ocean can hold an awful lot of heat, obviously, compared to an ice-covered ocean. I would think that the ocean must release a tremendous amount of heat back into the atmosphere in the autumn and the winter.

Stroeve: That’s true. And, there was another study that came out not too long ago that showed that where you have these periods of rapid ice loss, the warming that you get in the autumn can spread out to the adjacent land
Everything is connected, so when you change one component of the planet, the rest of the system is going to have to respond.
cover, and can cause temperatures over land to warm much quicker than they would under periods of moderate or no ice loss. And that’s a concern, of course, because then you are starting to affect permafrost temperatures, and there have been trends, of course, of the permafrost starting to thaw a lot more and getting warmer and if you just give it extra feedback, or now even warmer autumn temperatures, it’s a bit of a concern because the amount of carbon in the permafrost is estimated to be around 950 gigatons. So that’s a huge feedback signal looming there.

e360: And that would be released, that carbon, in the form, primarily, of methane?

Stroeve: In the form of methane.

e360: And when you mention that in the autumn you’re seeing — at least in the recent four or five years — temperature increases of 3 degrees C more, was that over land or over ocean?

Stroeve: We were just looking at it over ocean.

e360: You described the Arctic and its once year-round blanket of sea ice as “the air conditioner of the Northern Hemisphere.” What did you mean by that, and if you lose that ice-covered ocean, that air conditioner, could you see an impact on hemispheric weather patterns?

Stroeve: Basically it’s what keeps our planet cool, by having the presence of both snow and ice in both poles. So if you take that away you just start warming up the planet even more. And, we certainly would expect that to have an effect on atmospheric circulation around the planet, but exactly how that is going to manifest still remains quite unclear. The research on that is still very much in its infancy. But certainly, everything is connected, so when you change one component of the planet, the rest of the system is going to have to respond.

e360: Right, and in fact, at its simplest, isn’t global weather the transfer of heat away from the equator and the tropics towards cold regions at the poles?

Stroeve: Right, and so you change the temperature gradient, basically, between the poles and the equator, which will definitely impact your atmospheric circulation.

e360: You mentioned that this is all happening so fast, and that this research is in its infancy. Is there now a quickened pace of research about this whole issue of loss of Arctic sea ice and its impact on climate?

Stroeve: I think there is. I mean, we have a couple of grants right now that are focused on looking at impacts. One is on the temperatures, and one is on the snow cover. I think we’ve come to realize that the Arctic sea ice is going down, we understand why it’s happening, and we understand that it’s probably going to a state where it’s seasonally ice free in the near future. Now we really need to move into the realm of looking at impact studies.

e360: You think that in two to three decades, if these trends continue, there will be no Arctic sea ice in summer?

Stroeve: I do believe that — in summer. It would still get cold enough to freeze in the wintertime.

e360: What is your reaction to this unexpectedly rapid loss of ice and all these other feedback changes that follow from that?

Stroeve: I think when I first started out studying sea ice, or even just climate in general in the Arctic, I didn’t really think that we were in the midst of this global warming phenomena yet. But then, these last few years when we just continued to see these record ice losses, I started to change my way of thinking and realize that we are having a huge impact on our climate and we’re actually causing the ice cover to pretty much disappear now. And, yeah, it’s been alarming. Because we don’t really fully understand the implications of this, and I think that’s the biggest fear, is that we really don’t know what we are doing. It’s like we are playing with the dials on our climate and we don’t really know the outcome of it yet.

e360: Right, and I know some climate scientists talk about how sometimes the climate isn’t so much a dial as a switch, that things can change rather suddenly?

Stroeve: Yes, if you look at the geological record there is definitely evidence of very abrupt climate changes that have happened in the planet’s history. So, can our actions actually lead to something similar happening? That’s a scary thought.


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So what - climate change is a natural continual process that man did not cause and man cannot 'fix'. But I suppose it is all very interesting to read what MIGHT be happening and MIGHT happen (like a work of fiction based on bits of information that may or may not be actual facts) and it keeps research scientists and all the associated vested interests in paid employment I suppose and of course most importantly the AGW/CC fraud alive.

'we really don’t know what we are doing'

That pretty much says it all for me and when it comes to just about any climate issue its all pretty much gueswork with way too many ifs, maybes, not impossibles, etc for me (and I suggest any sane person) to get too excited or concerned about - but of course the loony AGW/CC zealots will sieze on any tenuous scrap from any 'expert' as proof of their unproven 'Co2 did it/is causing it/will cause it' assertion and therefore the world must waste trillions of dollars on non solutions for a non problem.
Posted by Wake up World on 25 Feb 2009

I don't know what is more depressing -- reading about the kinds of positive feedback loops we're already putting into motion, or reading the comment from "Wake Up World" that leaves me deeply skeptical about our ability as a society to actually address the problems we're creating.
Posted by Aaron Cosbey on 26 Feb 2009

'That leaves me deeply skeptical about our ability as a society to actually address the problems we're creating'

Fear not Aaron the news is good - 'man' has not created any climate problems and 'man' cannot 'fix' any climate problems that may exist now or in the future. What we need to do (like we have always done) is adapt to the natural, unstoppable process of climate change. These scientist should spend their time on addressing real pollution, real resource management (land/water/energy) and adaptation to natural climate change instead of wasting time and money trying to prove that we must reduce (which we can't anyway) atmospheric Co2 to somehow moderate the worlds climate - the idea itself is absolute madness but of course political power and money is driving the whole AGW/CC industry.

Posted by Wake up World on 26 Feb 2009

Congratulations Wake Up-you personify the arrogant, ignorance and viciousness of the anthropogenic climate change denialist perfectly. The Rightwing Authoritarian Personality type in trumps.
Posted by Mulga Mumblebrain on 26 Feb 2009

Thanks Mulga for the free character assessment and what a surprise - not. Whenever you AGW/CC sheep come up against common sense you always revert to personal abuse. Could you please detail exactly where I was arrogant (isn't it arrogant for man to think he can control nature/the worlds climate?), ignorant (isn't the fact that all of the AGW/CC is pure theory ignorant in and of itself?) and vicious (isn't is vicious the way that AGW/CC alarmists use scare tactics to try and sway public opinion, attack any counter view and of course shut down debate).
Posted by Wake up World on 26 Feb 2009

It's time to stop the ridiculousness. Let's face it, Gore got rich and most of the world got fooled. This whole article, focusing on the melting article should mention that the Arctic ice is the largest in area on record. This after only one year of being at the lowest, which of course, was caused by a glitch in the satellite taking the data. When does this nonsense end?
Time to get a real job!
Posted by Chuck Cerenowich on 01 Mar 2009

Thanks for the input Jerome but your proposal rests on an unproven theory that I and a very large number of people reject – namely ‘Individuals CAN prevent Global Warming’

There is absolutely no conclusive scientific proof to support this assertion (other than bogus manipulated ‘models’). However, we have to be very careful about the error of connection – i.e. you have to make a very clear disconnect between all aspects of the fraudulent AGW/CC theory and pollution, resource/water/energy/land management and adaptation to the unstoppable process of climate change (yes of course the climate is changing, it always has and it always will and the activities of man never has and never will have any material effect on the world’s climate). Therefore, every sane responsible person must totally support logical fact driven action to tackle real pollution, real resources management and adapting to climate change AND NOT SUPPORT the bogus and likely fraudulent AGW/CC theory and the efforts of dishonest governments, the UN and individuals with vested financial interests to reduce global Co2 emissions (cannot be done) in a ridiculous attempt to lower the temperature of the globe as if man had access to a giant thermostat (cannot be done).

Posted by Wake up World on 04 Mar 2009

Global warming is a bunch of BS.

What is the correct temp for the earth anyways 2009, 2000, 1970 or 1900's temp? I don’t think any of you people have an answer. So until you know the answer of where you are going don’t you think you should find out, before you start traveling down the road of even trying to change the climate?

Arrogance is thinking we are capable of having a large effect on climate. People like me would be called humble not arrogant.

Posted by Frank Griffin on 05 Mar 2009

The more we learn about global warming, it seems the more our alarmists scientists don't actually know what they are talking about. I have not seen a single scientist that predicted 5 or 10 years ago that we would have ice free passages in the arctic before 2040. Yet we do.

Al Gore's book, 'An Inconvenient Truth,' tried to scare us with predictions of an Ice free passage by the summer of 2050.

Maybe it might be time for a few scientists to admit they can no more predict the future of climate change, than a local weatherman can predict if it will rain this July 4th. It may be getting warmer, but the why, how, and where is a basic understanding that seems to be lacking. Except for the faithful believers.
Posted by f1fan on 06 Mar 2009

When the author said "we don't know what we are doing," she was referring to the whole human race and our blind refusal to take responsibility for our behaviors.

Nowhere did she say that man has no impact on climate -- in fact, she said the opposite.

Again, no one claims that climate has not varied in the past. The difference today is that for the first time in recorded human history, man has become a wild card in climate equations. In a natural system, without man's intervention, natural systems -- the ocean, forests, permafrost, etc. -- acted as climate modifiers by capturing or releasing greenhouse gases as changes occurred.

Today, we continue to pump gases into the atmosphere even as we see the oceans becoming saturated, and as we destroy tropical forests and wetlands that hold large amounts of carbon. Add that to the disappearing sea ice and the implications for methane release from the permafrost, and ANY intelligent person would be scared.

Some of the reactions on this space explain why the US is falling rapidly in terms of science education....

Posted by Jan on 08 Mar 2009

Thanks Jan and I think that here again we have the error of connection between real pollution etc versus the theory of AGW/CC.

You are aware aren't you that there is no conclusive proof whatsoever that global atmospheric levels of Co2 have any material effect on the natural unstoppable process of global climate change, nor is there any proof (in fact there is proof to the contrary) that there is any correlation at all between increased Co2 levels and global warming.

I think you like a lot of people need to remove the emotion from the issue - the emotion that the AGW/CC industry relies upon to perpetrate its fraud.
Posted by Wake up World on 08 Mar 2009

Jan wrote
"The difference today is that for the first time in recorded human history, man has become a wild card in climate equations. In a natural system, without man's intervention, natural systems -- the ocean, forests, permafrost, etc. -- acted as climate modifiers by capturing or releasing greenhouse gases as changes occurred."

1st of all man is part of the natural system. It's not like we came from outerspace and just started screwing up the planet.

2nd Ever notice how every generation thinks they can effect something they can not or don't?

How does Jan know that throwing virgins into volcanoes, or sacrificing people to the sun god did not have more effect on the climate than, letting a 100,000 people die every year because we drive the price of gas and heating oil up, or prevent poor countries from generating enough electricity to keep the sick and infirm healthy.

Greens say we need to make sacrifices but the truth is, sacrifices mean some will die that would not otherwise.

The other truth is that unless we do something really serious in this country like build about 100 nuclear power plants nothing else we do will matter.
Posted by f1fan on 09 Mar 2009

Deep freeze in western Greenland
The ice between Canada and southwestern Greenland has reached its highest level in 15 years.
By Af redaktionen Print
12-02 - 21:01

Minus 30 degrees Celsius. That's how cold it's been in large parts of western Greenland where the population has been bundling up in hats and scarves. At the same time, Denmark's Meteorological Institute states that the ice between Canada and southwest Greenland right now has reached its greatest extent in 15 years.

Overview of conditions (December 2008)

Average Arctic sea ice extent for the month of December was 12.53 million square kilometers (4.84 million square miles). This was 140,000 square kilometers (54,000 square miles) greater than for December 2007

Of course the caveat is that while ice sheets are increasing dramatically they are still smaller than some average of years. The fact remains ice coverage is dramatically increasing as it gets cooler.

Carbon dioxide is continuing to increase. The UN IPCC irreversibly guarantees that carbon dioxide causes global warming and yet it is cooling. Please, someone explain...and please be careful not to use comparisons to selected averages, this tactic does not fool anyone. Explain why every temperature curve from 2001 to the present is flat or slightly down.

According to NASA's GISS headed by James (Bush is censoring me) Hansen the worldwide average global temperature from 2007 to 2008 dropped a full .75 degrees celcius. Somehow when temperatures rise it is global warming, when temperatures fall it is weather. Seven computer programs at the IPCC said we would have warming for 100 years and it is cooling, dramatically.
Posted by Dahun on 10 Mar 2009

To the Erudites;

In between programs warning of Global
Warming, I saw a program on Discovery saying
the reason the Vikings were able to settle on
Greenland 1000 to 1100 or so , was because it
was much warmer* then and they could grow

Is this true? I keep asking the Greenees, but
so far, nobody answers.

Bill Price PKS- NC

*Was it because of of cow belches, an increase
in global beer consumption, or what ?
Posted by Bill Price on 21 Mar 2009



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