Thursday, March 20, 2008
The Arctic ice, past and present
While the total area of Arctic sea ice has apparently rebounded dramatically from last summer's lows (which induced no end of claims that we were on the verge of a climate change tipping point), scientists are now arguing that even during this cold winter there is substantially less of the very thick "perennial" sea ice than in recent decades.
"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.
The Arctic lost an unprecedented amount of ice during last summer's unusual warmth, and Meier said conditions are right for a similarly large melt if the temperatures are at all above normal this year. The area of thick Arctic ice lost over the past two decades equals 1 1/2 times the size of Alaska.
While normal weather variation plays a role in yearly ice fluctuations, officials said the dramatic decline in perennial ice -- which can range from 6 feet thick to more than 15 feet thick -- appears to be consistent with the effects of global warming.
Officials said the loss of long-lasting ice was less the result of warming of the atmosphere than of a long-term rise in ocean temperatures and the effects of the "Arctic oscillation," a variable wind pattern that can either keep icebergs in the Arctic (when the wind pattern is "negative") or push them south (when it is "positive"). Climate experts believe that both the rising water temperature and increasingly frequent "positive" oscillations are a function of global warming.
So that's bad news, for those of us who believe that nature should indemnify us against change. But here's some good news: 3,000 robots dispatched to report the extent to which the oceans are warming have actually reported that they are cooling, which is very confusing not least of all to the people at NPR. (CWCID: Glenn Reynolds.)
The problem, of course, is that we are all so used to random press coverage of expert opinion that it is very difficult for the average person to make sense of it all. Under three minutes of searching the archives of the New York Times, for example, reveals this story, in which an expert confidently predicts that the Arctic Ocean "will soon be open sea" and finds lots of other people to agree with him (there are dissenters, too). The date on that article: February 20, 1969. (Read the whole thing here, and note especially the reference to "the century of climate warming before 1940 or 1950".)
Now, obviously ancient predictions by long-retired people without access to the technology that we have today do not impeach today's experts, but they do put the average informed citizen with access to the internets in a difficult spot. How are we to know that the science -- and I use the term seriously, not mockingly -- will not change again? Basically, we have to go on faith.
11 Comments:
By 
, at
Thu Mar 20, 09:11:00 AM:
In all of your reading on this subject have you come across any articles discussing the earth's forest cover, and specifically whether or not it has lessened appreciably in recent years? I ask because if CO2 build-up in the atmosphere, even a minor build-up, can possibly cause changes in climate then we should all be interested in learning about significant reductions in forest cover, if those have occurred.
By , at
Thu Mar 20, 09:20:00 AM:
Glen Reynolds said it best:
I will believe it is a crisis when those who say it is a crisis start acting like it is a crisis.
I started saving the environment in the 1960's. We didn't call it "reducing the carbon footprint" or anything fancy like that. I took the bus to college, rode my bike to work and poured the first cold water from the hot tap into a pitcher to flush the water saving toilet. I saved aluminum cans for decades to save 90% of the electricity needed to make the cans from bauxite, and the true believers in Al Gore burned thousands of tons of jet fuel flying to Bali for a conference.
I will continue to reduce, reuse and recycle for the rest of my life, and the Democrats and Republicans will flood the country with millions of additional illegal immigrants, who will use up everything I have saved over my entire lifetime in a few seconds. If is was a crisis 40 years ago why were millions of illegal immigrants allowed to move into the country? If it stopped being a crisis at some point, why wasn't I informed? I believe in global warming, I have no faith in Barbara Boxer (D), Diane Feinstein (D) or Loretta Sanchez (D).
By , at
Thu Mar 20, 10:32:00 AM:
And then there is the distinct possibility that the mathematical model used for predictions is a tad off, e.g., assuming an infinitely thick atmosphere in formulating the PDEs. When someone takes a second look and revises the mathematics to more conform with reality, things change: http://www.dailytech.com/Researcher+Basic+Greenhouse+Equations+Totally+Wrong/article10973.htm
By 
Ray, at
Thu Mar 20, 01:44:00 PM:
The test of science is experiment. Since it's hard to create a microearth in which to check on microclimate changes, the next best thing we have is predictability.
Does there exist a climate model, such that, when I insert the data from 1989, and crank one year forward, I get the data from 1990? Is this true for every data point on the historical record? Great! Now let's plug in 2008. And check on it in 2009. If it still checks, *then* you might be able to use it. For predicting one year into the future :)
Everything short of that, is speculation. It may be better or worse informed speculation, but it is not science.
By , at
Thu Mar 20, 04:07:00 PM:
>The problem, of course, is that we are all so used to random press coverage of expert opinion that it is very difficult for the average person to make sense of it all.
>
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Given the truth of this, one must wonder why some intelligent and otherwise reasonable non-experts resist so stridently the considered opinions of groups like the National Academy, Royal Society, American Meteorological Society, World Meteorological Association, American Geophysical Union, NOAA....
- mattt
By TigerHawk, at
Thu Mar 20, 05:16:00 PM:
Well, mattt, I believe that greenhouse gases will cause the warming of the climate at the margin. I'm not so sure that once we move beyond that proposition to (i) the extent of consequences and (ii) the best policy to deal with those consequences I do agree.
By , at
Fri Mar 21, 12:53:00 AM:
this is good ice, that is bad ice, try and keep it straight. i remember once some clown on the radio saying how recent rain was going to make a local drought worse.
By , at
Fri Mar 21, 12:58:00 AM:
If this proves anything it proves that AL GORE and the greens have been lying all this time and its time for them to face the music and that gose for DAVID SUZUKI
By , at
Fri Mar 21, 01:41:00 PM:
@ TH-
I'm not sure either. But if we're going to formulate any long-term plans that would be affected by global climate change it seems they should be based on the considered opinions of people who are best informed, trained and experienced in analysis of the data, and not on the payroll of those who have an interest in maintaining the status quo.
- mattt
By , at
Fri Mar 21, 01:55:00 PM:
Another thought...
Why are the people who scoff at basing future plans on "speculation" about global climate change, often the same people who claim that we should cut taxes in order to increase revenue over the long term? I mean, if speculation on imperfect data is foolish, we'd better raise taxes quick to balance that budget!
The charitable explanation for the inconsistency is that people who understand economics and finance better than climatology, are more comfortable calling projections of gov't revenue "predictions" while climate forecasts are "speculation." Like I said, that's the charitable take. ;)
FWIW, meteorologists have a much better record for accuracy in predictions than economists over the past 50 years.
[And btw this is not specifically @ TH as I haven't read your blog consistently enough to know your take on these issues in detail.]
- Mattt
By , at
Thu Jun 05, 01:12:00 AM:
I always like it when the uber right use the "chickenhawk" argument on the greens. Wasn't that supposed to be a no-no ?
