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/.
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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:
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.
pardon if someone else has mentioned this (I didn’t have time to read all the posts)
I read a study about a year ago that calculated that Arctic sea ice loss is a net negative feedback. To paraphrase:
For most of the year the sun is so low to the horizon that little energy even reaches the ground to be reflected. Yet, open ocean is a superb emitter of long wave radiation during the long and cold Arctic nights. Final tally is a net loss of heat.
I find this Michigan “study” incomplete, at best. It seems to have ignored the increase in outbound energy from open waters.
OMG Anthony, that was great
villabolo says: “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.”
Oil company paying for cliche of the day? I haven’t gotten my oil company check for the 19th of January. Who do I call to complain about this?
Northern hemisphere albedo is important in spring and summer, when the sun is high in the sky. I didn’t find a plot for summer snow cover at Rutgers. The spring plot is
here. The 44-year trend is clearly downward. A 12-month running mean of the snowcover anomaly is here. The 45-year trend is clearly downward.
jajajajajajajajajajaja
almost like my ….
I miss R.Gates… LOL
John Kehr says: January 18, 2011 at 7:47 pm
John, the land in cities is not barren. Many cities have plenty of trees and plants, especially in their residential areas. The urban heat island is caused by the amount of asphalt, brick, cement and other heat absorbing/slow releasing mass and concentrated heat sources inside the urban area combined with the lack of plant mass as compared to rural areas.
I live in the country. It is often 10F degrees warmer in town than at my house, especially in Winter. However, it doesn’t take long for the effect to disappear as you get just a short distance out of town.
@Karl Horrex Hren says:
January 19, 2011 at 6:13 am
You don’t get out much do you? You still living with your parents? Nowhere to escape??? For goodness sake, get a life, and get a sense of humour.
Btw, no listing for “pornogrification” in the Oxford Dictionary.
Linear thinking to go with all these linear effects. If new uncovered land is exposed, plants spring up and suck up both incident solar energy and CO2. Darn this foxy contrary planet. It clearly resists change vigorously no matter which way climate is headed at a given time. I see this feature as becoming a nobel prize winning central law of climate sometime later in this revealing century. The obvious cycles of ice ages, temp, rainfall, snowfall, sealevel,… Have a pendulum (complex) formula about a mean. We will discover this mean during this century – probably found to be calculable by disinterested physics – a discipiine that seems to be so impotent and ideological these days.
It has intrigued me how those concerned with CAGW will point out the reduced Arctic albedo via water vs. ice at via low angles; yet, they do not mention the reduced albedo of roads, pavement and rooftops. If I believe #s on the internet, the total of these areas of manmade alteration is about equal to the decrease in ice coverage in the Arctic. Plus roads, pavements and roofs have more direct sunlight than the Arctic. Add on to that, the practices of farmers to plow up land, exposing black dirt. If albedo matters, anthropogenic influences on climate come from more than CO2!
Looking at the whole year and not just winter, a different picture emerges.
http://nsidc.org/sotc/snow_extent.html
from the NSIDC
“The 28 year trend in snow extent derived from visible and passive microwave satellite data indicates an annual decrease of approximately 1 to 3 percent per decade with greater deceases of approximately 3 to 5 percent during spring and summer. Precipitation in regions of seasonal snow cover appears to be constant or increasing slightly in some locations over the same time period, which suggests that diminishing snow cover is the result of increasing temperatures. ”
And Ann Arbor can be found under a streetlight near the bus depot most evenings.
“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.”
That means that in the Southern Hemisphere since 1979, the average temperature rose by only about 0.2 degrees Celsius. Obviously the Northern Hemispere is heating much more rapidly than the Southern Hemisphere. What do the models tell us about such disparity in the warming of a single planet?
Looks to me like the baby ice has reached maturity.
More information on the author of the paper (Flanner), that is not in his CV, here:
http://farm6.static.flickr.com/5007/5371140506_4444bb8ce8_z.jpg
JeffT says:
January 19, 2011 at 7:51 am
Northern hemisphere albedo is important in spring and summer, when the sun is high in the sky. I didn’t find a plot for summer snow cover at Rutgers. The spring plot is
here. The 44-year trend is clearly downward. A 12-month running mean of the snowcover anomaly is here. The 45-year trend is clearly downward.
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So what Jeff? In NASA article below NASA shows it doesn’t matter, nada. Take you complaints on decreased albedo up with them. Learn. Read:
http://earthobservatory.nasa.gov/Features/ArcticReflector/arctic_reflector4.php
Anthony Watts, maybe you should put at the top of this blog a definition of what a Watt is. You could call it “Watts Up With That with what a watt is.”
Bovine flatulence.
Wayne Reur January 19, 2011 at 1:34 pm & JeffT
The author, Kato of NASA does not mention the relative albedo of sea ice versus water at high latitudes. According to another 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 as or more than old snow, (atop sea ice):
NASA 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
Thus it would seem that the assumed feedback alleged in the models is exaggerated and may even should be of opposite sign.
Further my post above, just to make the Kato arguments more incomplete, if it is cloudy, the sunlight would be more diffuse, so that there would be less reflection from the water.
James Sexton says:
January 18, 2011 at 10:17 pm
QUOTE: “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?”
There’s snow in the winter. I get that. There’s sea ice in the winter, too. It’s winter, it gets cold in the winter, and that’s not going to change for a while, with or without your derisive “warmcold.” But you miss a point. There’s supposed to be snow on the ground in Spring, too–maybe not as much as during the winter, but if you look at the Rutgers graph, we’re still talking about 75% of the winter’s snow extent. That means that spring snow means something, despite your dismissal.
What does snow in NH spring tell me? Well, given that the snow extent is decreasing at a more significant rate than the changes in winter or fall, I’d say that it means that snow is melting earlier than it has in decades past.
Quote: “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.”
Yes, but you seem to assume that he means the snow and ice extent in winter. Nowhere in the article you linked does it specify that they’re looking ONLY at winter extents. The significance of the drop-off in spring extent is reinforced by the fact that it is happening in North America AND Eurasia. The slight increase in North America’s fall extent is offset and slightly outdone by a drop in Eurasian fall snow extent. The resulting NH trend is insignificantly negative. That suggests to me that the slight upward linear trend in North American fall extent has much more to do with shifting weather patterns than global cooling. Take a look again.
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=eurasia&ui_season=4
Quote: “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.”
Shall I suppose, then, that you have done that? Can I further suppose that you have copied the data into Excel along with the NH temperature data during the same period and run a regression analysis? If you’re going to use a statistical word, show me the calculations that go along with it.
Quote: “Anyone else see an oscillation?”
Perhaps I lack your imagination, but no, I don’t see an oscillation in the North American fall chart. I defy you to find a coherent physical model beyond simple ENSO effects (which are year-to-year anyway, and presumably not what you were talking about) that sufficiently explain that irregular variation. If you can, I will happily eat crow.
Many of our most venerated religious paintings, frescoes, sculptures, and sacred text consider unadorned body parts to be wonderful things. So do I. Let’s not be disingenuous in our moral purity. Human parts, made in the image of the Creator, and as depicted in the ice, are no more pornographic than Michelangelo’s David.
To me, a woman covered from head to toe in a burka and being sold to another man to pay for some debt, is so much more pornographic than this.
villabolo says:
January 18, 2011 at 10:04 pm
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!
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Sooooome quote!
You use as a reference ANOTHER TAXPAYER-FUNDED ALARMIST who puts James Hansen to shame at times.
And yes the TAXPAYER-FUNDED was in CAPS for a reason.
Chris
Norfolk, VA, USA
Dear mods a post I just sent might have gone to spam. Thanks for checking.
Chris
[Rescued & posted. ~dbs]
BTW I guess we can come to one unanimous agreement here:
There is such a thing as a circumcised iceberg. LOL
~Chris
By the way, it is now politically correct, important, and will become law to caution all the cracked nuts and fruitcakes out there to NOT take this stuff literally. So do NOT stick your “member” in the freezer. It is metaphor. There. Just thought I should help Anthony out by posting the now required warning label.
Here’s yer sign (thank you Jeff Foxworthy and friends).