Yes, I know you've all heard that we've had "record" refreezing of Arctic ice. Big shock there. We had record melting followed by a temporary cooling La Niña event. What those denier/delayer-1000 talking points don't tell you is that the refrozen ice is very thin and still at record low levels following the staggering ice loss this summer.
To set the record straight, on Wednesday, the National Snow and Ice Data Center and NASA had a teleconference to show the surprising and alarming new data from NASA's ICESat satellite, which revealed over the past year "the steepest yearly decline in perennial [i.e., old, thick] ice on record" (click to enlarge):
The key point is that ice volume is ice area times ice thickness. The seasonal ice (1 year old or newer) is thinner and will quickly melt away and disperse in the wind. This is global warming, folks:
On March 18 the scientists said they believe that the increased area of sea ice this winter is due to recent weather conditions, while the decline in perennial ice reflects the longer-term warming climate trend and is a result of increased melting during summer and greater movement of the older ice out of the Arctic.
The Washington Post had a must-read story on this yesterday:
"Because we had a cold winter, the public might think things have gotten better," said Walter Meier of the National Snow and Ice Data Center at the University of Colorado at Boulder. "In fact, the loss of the perennial ice makes clear that they're not getting better at all."
The surprising drop in perennial ice makes the fast-changing region more unstable, because the thinner seasonal ice melts readily in summer ...
Flying over the Arctic, one might perceive the sea ice cover as broad, Meier said, but that apparent breadth hides the fact that the ice is so thin. "It's a façade, like a Hollywood set," he said. "There's no building behind it."
What a perfect metaphor for the delayers. Their arguments seem solid and impressive, but it's all a façade.
All of this thinning data comes comes on the heels of the February data reported from NOAA's National Climactic Data Center, which pointed out that the area of Arctic ice is still historically small:
... the February 2008 Northern Hemisphere sea ice extent, which is measured from passive microwave instruments onboard NOAA satellites, was below the 1979-2000 mean, but greater than the previous four years. This was the fifth least February sea ice extent on record. Including 2008, the past five years had the least February sea ice extent since records began in 1979. Sea ice extent for February has decreased at a rate of 2.8 percent/decade (since satellite records began in 1979) as temperatures in the high latitude Northern Hemisphere have risen at a rate of approximately 0.37 degrees C/decade over the same period.
The planet is warming, and the surface is being transformed.
All of you delayers out there who are so sure that we are in a cooling and ice-refreezing trend, I await your acceptance of my bet: the Arctic Sea will be at least 90 percent ice free by 2020. Absent any takers this year, I can only assume you all don't actually believe the nonsense you are spouting.
This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.
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Comments
View as Flat
Pangolin Posted 1:27 am
21 Mar 2008
Since it's reasonable to assume that there was some global warming prior to 1978 then I would say that this winters refreeze isn't anything to crow about. Rather than being years old the ice present is months old and in some cases days old. It doesn't represent the thermal buffer it did in 1950.
Anybody who thinks this is a refutation of AGW should be asked if their willing to be ejected from a boat at the North Pole come September 15th. Within 10 years I believe the chances of treading water on that date will exceed 75%. In 20 years the North Pole should be ice free by midsummer if present trends continue.
We have no idea what this will do for our weather but we can safely assume that open water at the North Pole will be a bad influence.
Put the Carbon Back
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Delay And Deny Posted 2:40 am
21 Mar 2008
From that article:
While the Arctic sea ice is changing fast, the same is not true in Antarctica. Comiso said the amount of ice surrounding the continent is little changed over recent decades, although some ice loss has been occurring around the continent's peninsula and on some glaciers. Antarctica is significantly less tied to the world's weather patterns and is considered to be less subject to the effects of global warming so far.
And what about those oceans?
http://www.npr.org/templates/story/story.php?storyId=8852 ...
Some 3,000 scientific robots that are plying the ocean have sent home a puzzling message. These diving instruments suggest that the oceans have not warmed up at all over the past four or five years. That could mean global warming has taken a breather. Or it could mean scientists aren't quite understanding what their robots are telling them.
And any way, the "record" for these things goes back what? A hundred years or so? How can we possibly know what it was like in Henry Hudson's day...he was searching for a "Northwest Passage" -- well, maybe it existed at a time like the Medieval Warming. We're still well within the range of what's good and natural for life on Earth.
"In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual." -- Galileo
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Pangolin Posted 3:54 am
21 Mar 2008
The physics of a water column dictate that the bottom of the column is always the coldest part (absent forced mixing) so that as long as there is any ice at the top of the column the temperature at the bottom will remain stable and therefore, cold.
That doesn't prevent water at the top of the column from heating up. So could you please stick to arguments that have some tiny chance of being valid?
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katakanadian Posted 4:12 pm
21 Mar 2008
>_<
I'm not supporting Jabailo but I have to point out Pangolin's error. Water is densest at about 4 degrees. In an unstirred frozen lake the bottom is actually the warmest part as colder water begins to organize itself into crystals which become part of the floating ice. Some natural stirring occurs in spring as the surface warms up toward the denser 4 degree point and sinks down through colder less dense 1-3 degree water. Once the column is all ~4 degrees then further warming will create a temperature gradient with the coldest water at the bottom.
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