There was shrinkage!

Apologies in advance…

From the University of Michigan press center

Shrinking snow and ice cover intensify global warming

ANN ARBOR, Mich.—The decreases in Earth’s snow and ice cover over the past 30 years have exacerbated global warming more than models predict they should have, on average, new research from the University of Michigan shows.

To conduct this study, Mark Flanner, assistant professor in the Department of Atmospheric, Oceanic and Space Sciences, analyzed satellite data showing snow and ice during the past three decades in the Northern Hemisphere, which holds the majority of the planet’s frozen surface area. The research is newly published online in Nature Geoscience.

Snow and ice reflect the sun’s light and heat back to space, causing an atmospheric cooling effect. But as the planet warms, more ice melts and in some cases, less snow falls, exposing additional ground and water that absorb more heat, amplifying the effects of warmer temperatures. This change in reflectance contributes to what’s called “albedo feedback,” one of the main positive feedback mechanisms adding fuel to the planet’s warming trend. The strongest positive feedback is from atmospheric water vapor, and cloud changes may also enhance warming.

“If the Earth were just a static rock, we could calculate precisely what the level of warming would be, given a perturbation to the system. But because of these feedback mechanisms we don’t know exactly how the climate will respond to increases in atmospheric carbon dioxide,” Flanner said.

“Our analysis of snow and sea ice changes over the last 30 years indicates that this cryospheric feedback is almost twice as strong as what models have simulated. The implication is that Earth’s climate may be more sensitive to increases in atmospheric carbon dioxide and other perturbations than models predict.”

The cryosphere is the planet’s layer of snow, sea ice and permanent ice sheets.

In the Northern Hemisphere since 1979, the average temperature rose by about 0.7 degrees Celsius, whereas the global average temperature rose by about 0.45 degrees, Flanner said.

For every 1 degree Celsius rise in the Northern Hemisphere, Flanner and his colleagues calculated an average of 0.6 fewer watts of solar radiation reflected to space per square meter because of reduced snow and sea ice cover. In the 18 models taken into consideration by the International Panel on Climate Change, the average was 0.25 watts per square meter per degree Celsius over the same time period.

Flanner points out that the models typically calculate this feedback over 100 years—significantly longer than this study, which could account for some of the discrepancy. Satellite data only goes back 30 years.

To further put the results in context, each square meter of Earth absorbs an average of 240 watts of solar radiation. These new calculations show that the Northern Hemisphere cryosphere is reflecting .45 watts less per square meter now than it did in 1979, due mostly to reduced spring snow cover and summer sea ice.

“The cryospheric albedo feedback is a relatively small player globally, but it’s been a surprisingly strong feedback mechanism over the past 30 years,” Flanner said. “A feedback of this magnitude would translate into roughly 15 percent more warming, given current understanding of other feedback mechanisms.”

To avoid the worst effects of climate change, the scientific consensus is that the global average temperature should stay within 2 degrees Celsius, or 3.6 degrees Fahrenheit, of pre-industrial levels. Scientists are still trying to quantify the extent to which the planet will warm as greenhouse gases accumulate in the atmosphere.

“People sometimes criticize models for being too sensitive to climate perturbations” Flanner said. “With respect to cryospheric changes, however, observations suggest the models are a bit sluggish.”

###

The paper is called “Radiative forcing and albedo feedback from the Northern Hemisphere cryosphere between 1979 and 2008.” This research is funded by the National Science Foundation.

For more information:

Mark Flanner:

http://aoss.engin.umich.edu/people/flanner

Michigan Engineering: The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At $180 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments, numerous research centers and expansive entrepreneurial programs. The College plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world-class Lurie Nanofabrication Facility. Michigan Engineering’s premier scholarship, international scale and multidisciplinary scope combine to create The Michigan Difference. Find out more at http://www.engin.umich.edu/.

==============================================================

I’m reminded of this:

…but I’m not so sure about the “shrinkage” of snow cover.

Rutgers snow lab shows it to be flat, that’s their trend line, not mine:

And for North America:

Of course then there’s the almost always ignored Antarctic ice and snow contrasting the Arctic:

Graph from NSIDC - no I don't know why they don't have 2010 data - click for source

 

But 30 years in the future, what will we see? Will the cycle reverse? Given NASA’s admission of inability to forecast the solar cycle, it illustrates how little we know about natural cycle forecasting. Also, where does the soot figure into the albedo change? There’s no mention of that.

OK I’m being lazy, but I’m just not motivated by this study to do much work, since it’s just old news rehashed. Suffice to say this entry is mainly for entertainment purposes only.

Now, we’ll watch the squabbling begin.

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Michael Jankowski

If true and albedo effects from “shrinkage” have been underestimated, then it further shows CO2 forcing has been overestimated.
Mr. Trenberth is really going to have a problem explaining the lack of recent warming now.

tokyoboy

I bet the Arctic ice trend is only a short-term facet of the 60- to 80-year cycle.
As (albeit indirectly) evidenced by newspaper articles from 1920-40s, the Arctic ice exhibited a heavy decline then.

Phil's Dad

Michael Jankowski says:
January 18, 2011 at 7:32 pm
“…it further shows CO2 forcing has been overestimated.”
You and I might agree on this but I suspect that the actual temperature measurements will be “corrected” rather than the theoretical outcomes.

Ignoring the obvious BS that annual snow coverage has been dropping, there is a serious problem with albedo feedback.
That problem is plant life. Plants grow in places where snow isn’t. Comparing the albedo of snow to barren ground is what they do and the results of plants are completely different. Plants convert the sunlight into chemical energy, shade the ground. The entire Heat Island Effect is the difference between plants and barren ground.
Aside from the problems of actual snow coverage being stable, barren ground vs. plants, the only other MAJOR flaw is that they only calculated the difference in albedo. There is no measurement or other actual climate data to back up their conclusions. All this really does is say they calculated a larger albedo feedback than the IPCC models already use.
This article is about as impressive as the Patriots performance was on Sunday.

So instead of “climate perturbations” what the warmers have really been doing are “climate masturbations.” They’re such wankers.

Travis S.

It seems every time there’s a post here countering the claim of shrinking NH snow extent, the Rutgers chart for NH winter is used. What about other seasons? After all, winter is going to be cold simply because it’s winter. What of spring? The same Rutgers data seem to show a very significant decline in springtime snow cover in the northern hemisphere. Is there a reason Spring snow extent does not matter?
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=nhland&ui_season=2
The decrease in springtime extent in North America would also seem to overmatch the advertised increase in winter snow extent there, implying that the snow is melting faster and/or earlier, despite the greater winter extent.
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=namgnld&ui_season=2

Bcreekski

How can so much attention be focused on a single causal agent – CO2? It is sure folly to pick one substance and then relate all subsequent actions to that substance. I am reminded of the linkage between toilet paper and cancer.

Anything is possible

Now Anthony Watts enters the weather porn business! (:-
REPLY: Touche’ 😉

hunter

Another piece of trash for the ‘worse than expected bs bin’.
Now containing about 17.8 million pieces of trash.

Dr. Dave

The U of M has quite a reputation. I very nearly attended that school but passed for a lot of very stupid reasons. Instead I ended up at the Creighton University Health Science Center in Omaha (and to think…I could have been in Ann Arbor for the annual hash bash). Turns out I received a better (although more expensive) education. Eventually I was in the position to hire residents. What I discovered about UM grads is that they seemed to have been taught more about how ‘special’ they were for being UM grads than they did about the science they were supposed to know. No doubt, they turn out a number of brilliant grads (all schools do), but quite a sizable proportion of their grads and faculty are mediocre at best. If Mark Flanner didn’t have the “U of M” associated with his name I seriously doubt such drivel would have been published.

R. Shearer

Meanwhile, it’s 22F in Ann Arbor and the ground is covered with snow.

Obviously with this new information GISS will need to recalculate the temperature record for the past 100 years since it clearly has been worse than we thought.

John Kehr:
January 18, 2011 at 7:47 pm
You know, it does snow on plants. Ever heard of Evergreen forests? My lawn is greenest in Winter here in Western Washington. So when the snow melts, there’s a drastic change in albedo.
having said that, I don’t really see albedo having much of an effect. otherwise major snow cover like we’ve had in recent years would cause another ice age. It doesn’t seem to get colder BECAUSE of the snow, the snow comes BECAUSE it gets colder.

Russell

analyzed satellite data showing snow and ice during the past three decades in the Northern Hemisphere, which holds the majority of the planet’s frozen surface area”
This is like analyzing human behaviour based solely on female responses, because females make up a majority of the world’s population… You can’t just leave out an enormous chunk of data because it weakens your argument (or can you these days?)

King of Cool

Well Elaine may discover that George’s private parts shrink when they freeze but every time I leave a bottle of beer in the freezer it blows the top off.
Also, I hope that there are no icebergs like the one in the picture on the present tax funded jolly to the Mertz Glacier for the ABC’s Karen Barlow:
http://blogs.abc.net.au/news/breaking-the-ice/
as it seems that all she has had to look at so far is icebergs and she might be get the wrong idea.
But, can’t wait for some ice shattering news from this expedition although after watching the video at Jan 4 post with Dr Steve Rintoul, I can’t help wondering if most of these expeditions already have their conclusions written and they are just going along to collect the evidence to back them up.

savethesharks

“People sometimes criticize models for being too sensitive to climate perturbations” Flanner said. “With respect to cryospheric changes, however, observations suggest the models are a bit sluggish.”
===========================
Hey Flanner, why don’t you take that up with Richard Lindzen, and report back to us?
Chris
Norfolk, VA, USA

Pete H

So, we have had..possibly….maybe…could be….and now we have….implication! Thank goodness my old science master is long gone! He would have had a screaming fit reading this garbage!

I got involved in the climate by mistaking a word while looking for lurid web sites. The site’s introduction was about the earth’s reflection of the sun. I got interested before I realized this wasn’t just a come-on before the good stuff. I then realized the word that got me started wasn’t libido but albedo. I’ve been hooked on WUWT ever since and don’t have time now for those other pages. God works in mysterious ways. 🙂

pat

And how about those clouds, you morons?

Bob_FJ

I don’t understand why there is thought to be a significant feedback effect when sea-ice melts because according to a branch of NASA, and as demonstrated when watching a sunset over the sea, when the sun is low in the sky, there is greatly increased reflection; about the same or more than old snow:
Definition [albedo]
A ratio of the radiation reflected by a surface to that incident on it.
Clouds are the chief cause of variations in the Earth’s albedo since clouds have highly varying albedo, dependent upon thickness and composition. Old snow is about 55% (0.55), new snow around 80% (0.8). water surfaces vary from very low about 5% (0.05) at high sun elevation to at least 70%(0.70) at low sun angles.
http://disc.sci.gsfc.nasa.gov/data-holdings/PIP/albedo.shtml
Sea ice tends to have old snow atop, (?) and when it melts, there is loss of insulation of the water, and increased evaporative cooling of the water. (and Trenberth reckons that 49% of total average surface heat loss is from evapo-transpiration.
It’s a travesty really.
I mentioned this to our friend eadler on an earlier thread, but he seems to have “not seen it”

Mark Twang

Reposted from previous thread:
Dear me.
Sometimes people reveal things in writing that they probably wish they hadn’t.
A commenter self-named “democracy” over at The Daily Progress, speaking of the Cuccinelli Probe, says, “What the Cooch fails to cite is that it is climate change atheists like himself who are the ones with the ‘criticism’ of Mann’s findings.”
Oh my, “climate change atheists”!
What is an atheist? One who does not believe in a given concept of the divine; a denier of religion.
Rarely does one see so bald an admission that climate change, for the vast majority of its innumerate adherents, is merely a belief.
How dare anyone not believe in Gaia! Or Thor! Or Quetzalcoatl!
I wish to propose to our esteemed friends in the IPCC cheerleading squad that they immediately replace the offensive term “global warming deniers” with “climate change atheists”. It’s so much more civil, and what’s even better, it’s far more accurate.
The ones with open but skeptical minds could even be called “climate instability agnostics”. There might even be hope for some of them. Call it Pachauri’s Wager…

BobN

I’m sorry, but you’re graphic is priceless.

wayne

For once I agree to a cetain point.
It seems to me related to Willis’s posts on GISSE forcings, see:
http://wattsupwiththat.com/2010/12/19/model-charged-with-excessive-use-of-forcing/. In absorbing what Willis was saying I did a small side analysis to see what forcings would have to change to best fit the GISSTemp records from a copy of Willis’s spreadsheet. See:
http://wattsupwiththat.com/2010/12/19/model-charged-with-excessive-use-of-forcing/#comment-554252 . What that seems to imply is that the models are underestimating the snow/ice albedo effect by 400% not merely half.
It also equally implies that greenhouse gas forcing should be at the same time reduced to 25% of what the GISSE model assumes. In other words, if you raise snow/ice effect by 4 times and reduce GHG effect by 1/4 yiou get the very tightest fit and highest r^2.
I thought that was so curious.

upcountrywater

…no I don’t know why they don’t have 2010 data –
Hide the decline.. gang, strikes again.
Maybe all the “rotten ice” , can be color coded to disappear.

grayman

CO2Insanity : I think the warmist have done a Climate Masturbation to that Iceberg. Anthony a good poster on the berg, good thing i had put my drink away from my computer. ROTFLMAO and cannot stop!

wayne

Woops above…
“What that seems to imply is that the models are underestimating the snow/ice albedo effect by 400% not merely half.”
shoudl have read:
“What that seems to imply is that the models are underestimating the snow/ice albedo effect by 1/4 not merely half.” or they should raise the effect by 400%, not 200%.

rbateman

When it is stated “Watts/meter squared”, what time frame does it take to accumulate those watts?
One second, minute, hour, day, week, month, year???

Layne Blanchard

Perhaps flat is the new flaccid?
….. That appears to be what was blocking the sun from shining over Greenland….

Anthony Scalzi

rbateman says:
January 18, 2011 at 9:06 pm
When it is stated “Watts/meter squared”, what time frame does it take to accumulate those watts?
One second, minute, hour, day, week, month, year???
—–
Watts is the rate, in joules per second.

wayne

Of course the last three years have shown the just the exact opposite, lots and lots of snow and ice… I’m sure these intelligent climatologers even know exactly what that means… expansion!
(please Anthony, no graphic necesary, leave it to their imaginations) ☺

dp

Winter snow extent hardly matters given there’s little of no sunlight to reflect and that part of the world when extent may have once existed and which is painted by the sun is done with a very grazing angle – which is to say it was never going to get a lot of solar energy to reflect or absorb. More importantly when you consider albedo, is the percentage of ice/snow cover (not extent, square miles) when sunlight is present (and therefore matters) because ice was not pervasive in extent, but thick where it exists. There are reasons besides solar heating that affect extent. If the area of sunlit ice/snow is in decline over time because it is thin then albedo is also going to change. Forget extent – what is happening in the late fall and early spring regarding ice and snow cover? Is that in decline?
But wait – there’s more. You have to consider shrinking ice over multiple seasons – this leaves bare ground to be exploited by plants, so there should be a lessening impact of ice shrinkage as the barren surface is populated over time.
Then there’s that issue of heat releasing water vapor into the atmosphere. If clouds are formed the feedback is negative. If it just gets stinking humid but clear there will be some heating. But with all that heat in the atmosphere, quite a bit of it is going to disappear into the void between the stars, never to be seen again, when the sun goes down. Hotter things radiate more energy per unit of time than do colder things assuming the temperature of the night sky is not also changing, so the rate of heat loss will go up, too.
And that leads to the changing temperature of the night sky. Earth’s alignment with and exposure to the galactic plane provides for seasonal changes in the average temperature of the night sky.
The precession of the Earth’s axis has created a situation where, for example, the galactic center can be viewed from the south pole but is over the horizon for the north pole. There will come a time when that changes and at that point the average temperature of the night sky ceases to be seasonal. That has to matter. Not in my lifetime, of course, but I do expect any decisions we make to our carbon footprint now will be unnoticed by the climate dynamics of that time in the future and through all the intervening years until then.

I believe in Thor.

villabolo

But 30 years in the future, what will we see? Will the cycle reverse?
30 years from now the Arctic will be ice free in the summer for extended periods of time. 4 weeks by the mid 2030s according to the Navy’s chief Oceanographer Rear Admiral David Titley’s report to congress. Sooooome reversal!
http://democrats.science.house.gov/Media/file/Commdocs/hearings/2010/Energy/17nov/Titley_Testimony.pdf
30 years from now you will see a whole different set of rationalizations by skeptics who will have, in Orwellian manner, forgotten everything that they were saying today and replaced it with the oil company paid for cliche of the day.
REPLY:Ah Trollobolo is back. My goodness, listen to yourself. NASA was just as certain about solar cycle 24 two years ago and today ate some serious crow. You are going to believe that our government science can forecast 30 years ahead? It’s like a streetcorner seerer proclaiming the second coming. It keeps getting pushed into the future. Is was 2013, then 2015, now 30 years out…whatever. If you believe what you write, have the courage to put your name to it, otherwise go back to haunting Romm – Anthony

Keith Battye

Belief is a poor substitute for knowledge every skeptic knows that that’s why they are skeptics.

James Sexton

Travis S. says:
January 18, 2011 at 7:54 pm
It seems every time there’s a post here countering the claim of shrinking NH snow extent, the Rutgers chart for NH winter is used. What about other seasons? blather, blather, blah, blah……..
======================================================
First, winter is used because that is when snow is suppose to be on the ground for most of the NH, snow in the NH in spring tells you what? That there may or may not be snow on the ground in April in some places of the NH? No doubt. But, let’s go to point at hand …….. Look at the graph your presented.
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=nhland&ui_season=2 No, really look at it. Now, let’s go back and see what the assertion was……… He seems to be saying, “The Northern Hemisphere sea ice and snow cover has responded quite sensitively to warming over the last 30 years,….”….in fact, he did say that. You can read that here.
Now, the graph. Correlate it to temperatures. You notice how the graph peaks around the late 70s-early 80s? The ebbs about 1990? Then peaks again late 90s and then decreases towards the present? You notice how well the correlates with this graph? Me either. You can turn this upside down, on its side, flip it around, or whatever. One has nothing to do with the other. Snow isn’t a thing of the past, the lack of snow doesn’t hot things up, the snow extent in the winter isn’t caused by warmcold, its simply a blathering of bs. It turns out, the albedo effect has been over-sensationalized for years. BTW, did you see this graph? http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=namgnld&ui_season=4 Can you reconcile that? Anyone else see an oscillation?

James Sexton

rbateman says:
January 18, 2011 at 9:06 pm
When it is stated “Watts/meter squared”, what time frame does it take to accumulate those watts?
One second, minute, hour, day, week, month, year???
========================================================
Thank you! That expression irks the heck out of me. Watts. Watts what? Do the climatologists not have an electric bill? Watts and watts over time are very different things. Is this a constant energy expression? If not, then time has to be declared, else, there is no way to quantify the energy.

Jim Steele

“To further put the results in context, each square meter of Earth absorbs an average of 240 watts of solar radiation”
My problem with these albedo studies is that largest increase in temperatures that contribute to the calculated global warming happens in the Arctic in the winter, when the average solar radiation is closer to zero. How big an impact can albedo have then?

David Falkner

Albedo from snow and ice? So the important factor isn’t ice volume, but ice area? Geez, that pea bounces from thimble to thimble. I swear, this is like playing with an octopus.

Dave vs Hal

Another photo caption “Global warming affects Arctic libido”

James Sexton

Jim Steele says:
January 18, 2011 at 10:26 pm
“To further put the results in context, each square meter of Earth absorbs an average of 240 watts of solar radiation”
My problem with these albedo studies is that largest increase in temperatures that contribute to the calculated global warming happens in the Arctic in the winter, …..
=======================================================
Or the other way around. They think snow should be on the ground in June in most parts of the NH.

AJB

See the ‘erection’ to the right of the graph on page 9 of the supplemental information (2.5MB PDF).
A true testament to modelling ‘ensemble’ bullshit, never mind the radiative myopia. File in the nearest dumpster.

NovaReason

Since people keep missing it…
http://en.wikipedia.org/wiki/Watt
Watts are joules per second.
It is not a time indeterminate value. It’s defined in the term watt. The reason you talk about kilowatt-hours when you’re determining things like your energy bill is because they don’t bill you on seconds used. They could (conceivably) but it’d be a pretty large number, and a very low value per watt. kW/h translates out as a kW applied for a full hour.

Frank

In the interest of fairness, you could show your readers data from the Rutgers snow lab indicating that spring snow extent has dropped about 10% over the last 30 years. And it would be fair to point out that the diminishing Arctic sea ice, but not stable Antarctic sea ice, contributes to the NORTHERN hemisphere cryosphere. Finally, if you look at Flanner’s Figure 1, which is not behind a paywall, you can see that there is a negligible change in the cryosphere in the winter and that the largest reduction (both snow and sea ice) occurs in the spring. (I had the impression the sea ice has been lower year round and the greatest drop was in the late summer.) Is it possible Flanner and the scientists who reviewed his paper actually know what they are doing?
It’s too bad all of the details are behind a paywall.
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=nhland&ui_season=2
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1062.html

I note that the “Hockey Stick” is alive and well in the minds of the Warmista community. Nature Geoscience published an article which claims that the “historical record” confirms the models…
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1057.html
I can’t make up my mind whether to laugh or cry, or take up arms. Of course the diaries of monks, temperature readings and other data confirm the “models” – that’s what the damned things are constructed on in the first place!

wayne

James Sexton says:
January 18, 2011 at 10:25 pm
rbateman says:
January 18, 2011 at 9:06 pm
When it is stated “Watts/meter squared”, what time frame does it take to accumulate those watts?
One second, minute, hour, day, week, month, year???
========================================================
Thank you! That expression irks the heck out of me. Watts. Watts what? Do the climatologists not have an electric bill? Watts and watts over time are very different things. Is this a constant energy expression? If not, then time has to be declared, else, there is no way to quantify the energy.

James… surely you jest! Watts IS energy per time, you know, power, not just energy, that’s joules or BTUs or calories. Watts aleady have the time you are searching for within, seconds, it’s joules/second.

David L

Another in the long line of “it’s worse than we thought” arguments.
What my scientific eyes see is how poorly they understand what’s going on. The models either overpredict or underpredict. Either way it’s strong evidence they have absolutely no clue what’s going on. Yet they “know” that reducing CO2 emissions will fix everything. How are they so certain of this idea when there’s so much uncertainty with everything else they spout?

ImranCan

Why is it that I just know that an analysis like this is just a piece of flawed BS ??? As Anthony says, I can’t even be bothered to look into it …..

GBees

Was that albedo or libido?
Either way warmth is better than cold ….

Jimbo

“Also, where does the soot figure into the albedo change? There’s no mention of that.”

Here you go.
Nasa says “…aerosols likely account for 45 percent or more of the warming that has occurred in the Arctic during the last three decades.”

Soot:
“We conclude that decreasing concentrations of sulphate aerosols and increasing concentrations of black carbon have substantially contributed to rapid Arctic warming during the past three decades.”
Climate response to regional radiative forcing during the twentieth century
[Full pdf paper]

“Plausible estimates for the effect of soot on snow and ice albedos (1.5% in the Arctic and 3% in Northern Hemisphere land areas) yield a climate forcing of +0.3 W/m2 in the Northern Hemisphere. The “efficacy” of this forcing is ~2, i.e., for a given forcing it is twice as effective as CO2 in altering global surface air temperature.”
Soot climate forcing via snow and ice albedos

Jimbo

I don’t know what the Arctic will do this September but I read from Steven Goddard that:

“US Navy PIPS data shows that the area of ice greater than 2.5 metres thick – has doubled since the same date in 2008.”
http://stevengoddard.wordpress.com/2010/12/31/area-of-thick-arctic-ice-has-doubled-in-the-last-two-years/

More details here:
http://hidethedecline.eu/pages/posts/trends-in-arctic-ice-thickness-and-volume-211.php

Jimbo

pat says:
January 18, 2011 at 8:45 pm
And how about those clouds, you morons?

Here you go!

NASA – Arctic
“So in addition to changing sea ice, we can kind of guess that something must be happening in the atmosphere over the Arctic, too.” Clouds are bright, too, and an increase in clouds could cancel out the impact of melting snow and ice on polar albedo.”http://earthobservatory.nasa.gov/Features/ArcticReflector/arctic_reflector2.php

“Although sea ice and snow cover had noticeably declined in the Arctic from 2000 to 2004, there had been no detectable change in the albedo measured at the top of the atmosphere: the proportion of light the Arctic reflected hadn’t changed. In other words, the ice albedo feedback that most climate models predict will ultimately amplify global warming apparently hadn’t yet kicked in.”
“According to the MODIS observations, cloud fraction had increased at a rate of 0.65 percent per year between 2000 and 2004. If the trend continues, it will amount to a relative increase of about 6.5 percent per decade. At least during this short time period, says Kato, increased cloudiness in the Arctic appears to have offset the expected decline in albedo from melting sea ice and snow.”
http://earthobservatory.nasa.gov/Features/ArcticReflector/arctic_reflector4.php

University of Columbia – Arctic
“The predicted substantial decrease in Arctic summer sea ice concentrations during the twenty-first century may favor cloud formation, which should diminish or even cancel the ice-albedo feedback by shielding the surface.”
“Water droplets are more effective in reflecting and absorbing solar radiation than nonspherical, typically larger ice crystals (Dong et al. 2001).”
http://www.ldeo.columbia.edu/res/div/ocp/pub/gorodetskaya/irina_ipccpaper.pdf