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Earth Science

Arctic Sea Ice Rallies a Bit 152

Posted by timothy
from the mysterious-ways dept.
radioweather writes "Like the recent stock market rebound, Arctic sea ice is making a big rally over the record low set last year. According to the Alaskan IARC-JAXA website, satellite data which shows sea ice extent as of 10/14/08 was 7,064,219 square kilometers, when compared to a year ago 10/14/08 it was 5,487,656 square kilometers. The one-day gain between 10/13/08 and 10/14/08 of 3.8% is also quite impressive. On May 5th, The National Snow and Ice Data Center suggested the possibility of an ice-free north pole in 2008, but so far, this year has been a banner year for sea ice recovery."
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Arctic Sea Ice Rallies a Bit

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  • by Drakin020 (980931) on Wednesday October 15, 2008 @05:22PM (#25390053)
    FTH:

    Like the recent stock market rebound...

    Uhh....what? http://moneycentral.msn.com/detail/stock_quote?Symbol=$INDU [msn.com]

  • News reports have indicated that the earth's weather climate has been constantly shifting over millions of years.

    Seriously, I wish people would stop getting so shocked about this. I remember reading in school about things like Ice ages and constaly changing climates, and I'm not that old. I beleive man's impact on the enviroment, while measurable, is severly overblown.
    • Re: (Score:3, Insightful)

      Lets ask this question:

      Do you want to walk on ice that froze an hour ago? or ice that's been solidly frozen for decades?

      The ice 'recovery' is a misnomer, even if it covers the entire arctic at peak winter, it won't be very thick compared with persistent perennial ice cover that has existed and built up thickness for hundreds/thousands of years.

      Replacing 'steel' with 'balsa wood' doesn't mean the structure can hold up the same weight. i.e. polar bears.
      • Except polar bears don't go that far north.

        Neither do people.

        Only Grise Fiord gets anyway near, and that has a dark story to it. Not only that but I think it's 3+ hours away from Pond Inlet, itself 6 hours from Iqaluit, itself 6 hours away from Ottawa. By plane. Yeah.

        There's Alert, but I really doubt those GI Joes are out huntin' for caribou nose and polar bears.

      • Uh dude, the age of the ice doesn't matter at all. Thickness is all that matters. Every year the lakes between Yellowknife and Diavik thaw completely, and every year when they ice over again people drive FULLY LOADED EIGHTEEN WHEEL TRUCKS OVER THEM.
        • The age of the ice does matter, because younger Arctic sea ice tends to be thinner, and is therefore lest likely to persist from year to year. Warming slowly wears away the thick multiyear ice. When that's gone, we could have no sea ice in the Arctic during the summer. Some young thin ice could form during the winter and then melt away again the next summer.

    • by Aranykai (1053846)

      An interesting article, that in my honest opinion, makes far more sense explaining the current global temperature changes.

      http://www.space.com/scienceastronomy/sun_output_030320.html [space.com]

      • by Rei (128717) on Wednesday October 15, 2008 @05:47PM (#25390523) Homepage

        I think it's cute how people like you think that the IPCC is either unaware of or deliberately ignoring papers like this ;)

        Seriously -- read the report some time. It'll be educational for you. There's something like 50 papers referenced for just sunspots alone. If it A) has to do with global warming, even tangentially, and B) was published in a peer-reviewed journal in the past 10-20 years, odds are it's in there.

        Science does not work in a manner of "this one paper says one thing about one aspect, so it must be God's honest truth!". The amount of research out there is pretty staggering. It is... let's just say "unfortunate" that the popular press has a habit of picking up one work or another and sensationalizing them.

    • by Ambitwistor (1041236) on Wednesday October 15, 2008 @06:44PM (#25391567)

      Seriously, I wish people would stop getting so shocked about this.

      Climatologists are not unaware that the climate has changed in the past. The issue is that climate is currently changing faster than it would have without human input, and that larger and faster changes are likely if we continue to increase our input to the climate system.

      • Re: (Score:3, Insightful)

        by LWATCDR (28044)

        You do know that we have a less then 200 years of good data on climate don't you?
        Heck I am even all for cutting carbon just to be safe.
        But what your so sure of you shouldn't be.

        • Re: (Score:3, Insightful)

          by Ambitwistor (1041236)

          You do know that we have a less then 200 years of good data on climate don't you?

          Yes, which is what tells us that the late 20th century warming is faster than natural, because we also have data on the usual natural sources of warming and cooling such as solar activity and volcanoes.

          But what your so sure of you shouldn't be.

          The Earth is 4 billion years old, but we don't need 4 billion years of data to understand something about what's happening to the Earth now. Sure there is uncertainty, and more than a couple hundred years of accurate data helps. But the instrumental data we do have is enough to tell us that something anomal

          • Re: (Score:3, Insightful)

            by JimboFBX (1097277)
            You do realize that all historical data that predates accurate measurements are just very rough estimates that are open to interpretation and completely unopen to experimental proof and disproof, right? I can't grab a rock, do something to for a million years, and prove that I was right that it looks the way it does because of it. As a programmer, I can argue that I'm initially wrong about the cause of bugs in programs I wrote 80%+ of the time. However, unlike a program, where i can prove or disprove myself
            • You do realize that all historical data that predates accurate measurements are just very rough estimates that are open to interpretation and completely unopen to experimental proof and disproof, right?

              I take your point, but you missed my main point, which is that we don't need paleoclimate data to support the manmade influence on the climate; modern observations are sufficient, although paleo data helps. You're right that there are substantial uncertainties, which is why the projections for 2100 vary by several degrees. But we do know enough to say that less than 1-2 degrees warming is unlikely, which is enough to be worth taking out some insurance against the possibility of greater warming.

              Climatology is more or less a pseudo-science, at best a scientific research project. It, by definition, is not humanly possible to prove right or wrong. There is no isolation of variables, perceived close similarities.

              I hate to b

              • by delt0r (999393)

                I take your point, but you missed my main point, which is that we don't need paleoclimate data to support the manmade influence on the climate; modern observations are sufficient..

                You keep saying this and its plainly wrong. If we have 200 years of data (which we only kinda have) we can't know anything about how often this type of shift happened in the past. Perhaps its all just one 400 year cycle? Without historic trends you cannot say a dam thing about current trends. Really this is science 101.

                • If we have 200 years of data (which we only kinda have) we can't know anything about how often this type of shift happened in the past. Perhaps its all just one 400 year cycle? Without historic trends you cannot say a dam thing about current trends.

                  That's wrong, because we don't have to rely on just looking at temperature trend data. With modern instrumental capabilities, we can actually look at CAUSES of climate change. Skeptics love to suggest that it's all just a "natural cycle", but natural cycles, like anything else, have causes. Past climate cycles have been due to things like variations in solar output, volcanic activity, changes in global ocean circulation, etc. Today we can measure solar output, volcanic activity, ocean circulation patter

          • Yes, which is what tells us that the late 20th century warming is faster than natural, because we also have data on the usual natural sources of warming and cooling such as solar activity and volcanoes.

            I'm not sure that's how it works. For instance, How did the global climate change between 1075 and 1100AD? Between 850BC and 870BC? etc We might have a fairly good idea for how climate in some areas changed over a period that INCLUDES that time period, but we have no data that is at all similar to what we have for the last maybe 100 years.

            But the instrumental data we do have is enough to tell us that something anomalous is going on, when compared to the various measured factors in the climate system which are normally responsible for climate change.

            This I don't understand either. It's like how downloaders can say "Download speed is currently 150kb/s, download will be done in 5 minutes." In reality that 150KB/s was a

            • We might have a fairly good idea for how climate in some areas changed over a period that INCLUDES that time period, but we have no data that is at all similar to what we have for the last maybe 100 years.

              I know. My point was that we can tell tell that there's something odd about the modern warming, based ONLY on the modern data. Specifically, we can measure the various sources of warming and cooling (solar irradiance, volcanism, industrial sulfate aerosols and particulates, natural and manmade greenhouse gases, etc.), and if we leave out the manmade greenhouse gases, we can't account for the atmosphere and ocean warming which we observe.

              This I don't understand either. It's like how downloaders can say "Download speed is currently 150kb/s, download will be done in 5 minutes." In reality that 150KB/s was an instantaneous spike--the average is more like 80kb/s.

              The difference is that we're not just measuring a transient response

              • by LWATCDR (28044)

                And I am saying that the level a belief in this put ways the dataset!
                I am not even saying that it isn't happening, I am not saying we shouldn't cut our emissions.
                I am saying that it is far from proven. I am just willing to modify my behavior based on the possible risk.

                • And I am saying that the level a belief in this put ways the dataset!

                  I have no idea what that sentence means, but it doesn't change the fact that CO2 levels can account for the warming we've observed, and the usual natural sources do not. The uncertainty is not whether CO2 is causing significant warming, it's about how much further warming from CO2 will be realized in the future.

                  • by delt0r (999393)
                    Sorry but your comment is at odds with all the current literature on Global Warming. In fact there are almost no climatologist that claim all the warming is man made. Its quite widely accepted that at least some is very natural warming. The is also a general view that future warming will also be part natural and part man made. CO2 levels account for *some* things via models with *estimated* parameters. This is not hard pure science (you can't repeat the experiment to verify the models), and so there is a bi
                    • In fact there are almost no climatologist that claim all the warming is man made. Its quite widely accepted that at least some is very natural warming.

                      I didn't claim otherwise. I'm pointing out that you can't explain the data if you think CO2 is a relatively small contributor.

                      The is also a general view that future warming will also be part natural and part man made.

                      We don't know whether future natural forcings will cause warming or cooling. We do believe that as CO2 levels continue to go up, the man made influence will continue to become relatively stronger than natural sources in either direction, barring something really extreme.

                      Read more than news papers please.

                      Why don't you? Try Tomassini et al.'s paper last year in J. Climate for a modern estimate of the relative natura

            • by Lars T. (470328)

              But the instrumental data we do have is enough to tell us that something anomalous is going on, when compared to the various measured factors in the climate system which are normally responsible for climate change.

              This I don't understand either. It's like how downloaders can say "Download speed is currently 150kb/s, download will be done in 5 minutes." In reality that 150KB/s was an instantaneous spike--the average is more like 80kb/s. With the amount of data we have, it seems like we're measuring the slope but we really don't know where we are on the curve? Given at most 100 years of solid data, do we REALLY know all that?

              Remember kids: this is said in an discussion about an article that insinuates an upward trend from the fact that there is a slight slump in a long downward trend.

          • by delt0r (999393)

            Yes, which is what tells us that the late 20th century warming is faster than natural.

            It does not. Perhaps you should look at the data. Its warming. But the rate is faster than natural... we think, we suspect, we guess. But we don't really know.

            We may not need 4 billion years of data, but more than 40 (aka satellites and ocean buoys etc) years of good data would be a start. Also ice cores have evidence of faster changes than we are experiencing. There is *nothing* unprecedented with current weather trends. The problem is how much is our influence. Read the scientific papers rather than th

            • by TheLink (130905)
              Given our present tech level it's probably easier to cope with X degrees too cold than X degrees too warm.
              • by delt0r (999393)
                If we look at history, the opposite would seem to be true. The little ice age was a disaster and cooling prevents crops from growing, while warming increases crop production.
                • by TheLink (130905)
                  Apparently it is easier to make the world warmer with our present tech level, than it is to make it cooler.

                  Therefore we can cope with cooler better than warmer :).
            • It does not. Perhaps you should look at the data. Its warming. But the rate is faster than natural... we think, we suspect, we guess. But we don't really know.

              The problem is that if you look at natural sources of warming alone, our measurements of the forcings along with our modeling of responses, indicates that it should have cooled instead of warmed. A difference in sign is a pretty significant anomaly.

              We may not need 4 billion years of data, but more than 40 (aka satellites and ocean buoys etc) years of good data would be a start.

              I certainly agree that more data helps, although the surface temperature record is usefully reliable for longer than 40 years.

              Also ice cores have evidence of faster changes than we are experiencing.

              The only faster changes we have clear cut evidence for in the ice cores are associated with collapses and restarts of the meridional ove

        • "But what your so sure of you shouldn't be."

          Good advise, but your own risk assesment that you are 'so sure about' doesn't have any probability caveates at all?

          The GP did have one such caveate (ie: 'likely'), the best science available says 'very likely'. But maybe I have misunderstood, maybe you are talking about the GP's implicit assumption that humans are causing the climate to change, if that's the case then the science says 'certain'.
        • by g-san (93038)

          you should google "ice core" sometime. you can even see the ppm of various gases over history on various websites. it's all there. look for yourself if you don't trust media/news/science research of unknown funding.

  • Statistics? (Score:4, Informative)

    by rwade (131726) on Wednesday October 15, 2008 @05:25PM (#25390115)

    According to the study's website [uaf.edu], the extent of the ice coverage is an estimate "calculated by certain algorithm."

    It would be premature to suggest this as a panacea without knowing the statistics behind this estimate. Without this, we don't know if 3.8% is even statistically significant? They don't even offer a margin of error.

    Even the "Data Download" [uaf.edu] offers only the bottom line estimate at a given point in time. What is the formula that feeds into that?

    • My quick Google search couldn't find the paper with the exact algorithm, but this paper [uni-bremen.de] describes a related algorithm. Skimming it, I can't tell what the error bars on 1-day deltas are. I do see from that paper that the biases between different data products can be larger than 4% (although they seem to be most likely more like 2%). I would imagine that time deltas are more accurate than absolute estimates. Anyway, bottom line is I don't know if it is significant, but you could probably dig up the algori

    • by delt0r (999393)
      When ever i even say something like that about the "facts" or data methods of AGW i will often get flamed into the stone age. After all what is the algorithm used to calculate the average temperature of the earth?

      Do you show the same level of skepticism when its something you already agree with?
      • by rwade (131726)

        Do you show the same level of skepticism when its something you already agree with?

        I don't agree or disagree that seawater is more or less freezing in Alaska than it was in the past. Since I'm not like...in Alaska, I can't know whether this estimate is wrong.

        It is simply not clear whether the shifts that this data shows are statistically significant.

  • by dtjohnson (102237)

    2008 [slashdot.org]
    is the coldest year of the 21st century and output from the sun is declining [slashdot.org].
    Maybe Al Gore and his carbon cult followers were...wrong.

    • by moosesocks (264553) on Wednesday October 15, 2008 @05:43PM (#25390461) Homepage

      Solar output and atmospheric heat retention are two completely independent variables.

      The fact that one is rising, while the other is falling is merely a fortunately coincidence.

      My own personal view is that there's a heck of a lot that we don't know about the mechanics of the atmosphere. Until we figure everything else out, though, it's probably a good idea to err on the side of caution.

      • Re: (Score:2, Interesting)

        by dtjohnson (102237)

        Solar output and atmospheric heat retention are two completely independent variables.

        At least you admit that solar output is a variable which puts you way ahead of most of global warming people. As far as the 'atmospheric heat retention' I presume you mean the effect of the atmosperic carbon dioxide concentration which is allegedly increasing heat retention. The evidence that a change in atmospheric carbon dioxide concentration from 280 ppm at the end of the last ice age to 385 ppm today has any effect a

      • by NotmyNick (1089709) on Wednesday October 15, 2008 @06:20PM (#25391149)
        Ironic isn't it that some people who so easily dismiss decades of research by thousands of scientists will so willingly glom onto one report that might ever so slightly support their lifestyle choice?
      • by AJWM (19027) on Wednesday October 15, 2008 @08:11PM (#25392639) Homepage

        My own personal view is that there's a heck of a lot that we don't know about the mechanics of the atmosphere. Until we figure everything else out, though, it's probably a good idea to err on the side of caution.

        And which side is caution on, exactly? Spending money (that could be used for other things) to reduce CO2 emissions "just in case", or not spending money tinkering with CO2 because if global warming turns out not to be anthropogenic, we could bring on the next (little?) ice age?

        (I happen to think the effects of a minor global temperature increase are a lot less serious than the effects of another ice age, but that my just be my Canadian upbringing talking.)

        • Spending money (that could be used for other things) to reduce CO2 emissions "just in case", or not spending money tinkering with CO2 because if global warming turns out not to be anthropogenic, we could bring on the next (little?) ice age?

          I'm sorry, but "Global warming is not anthropogenic" is no longer a credible scientific position. The serious scientific questions are along the lines of "Is climate sensitivity to CO2 closer to 2 degrees, or 4 degrees?"

          Incidentally, if you're concerned that reducing CO2 will bring on a "little ice age", then you've already conceded that CO2 levels lead to warming. And it's not hard to add more CO2 if we decide we want/need to. It's adding less that's hard.

          • by AJWM (19027)

            I'm sorry, but "Global warming is not anthropogenic" is no longer a credible scientific position.

            Among political scientists perhaps, physical scientists and particularly climatologists would argue otherwise.

            The fact is that CO2 is a relatively minor greenhouse gas (the effects of water vapor are several times as great), and anthropogenic contributions are a small percentage of global CO2 production (be eg geochemical processes). It may not even be the case that increased CO2 (of whatever cause) raises globa

            • Among political scientists perhaps, physical scientists and particularly climatologists would argue otherwise.

              You're obviously unfamiliar with the climatological literature. I follow the major journals every month. I invite you to peruse the latest issues of Nature, Nature Geoscience, Science, Journal of Geophysical Research, Geophysical Research Letters, etc., and look at how many papers dispute this point.

              The fact is that CO2 is a relatively minor greenhouse gas (the effects of water vapor are several times as great),

              The natural greenhouse effect is on the order of 30 degrees C, which is why the planet is not a frozen iceball. CO2 is a smaller effect, but a few additional degrees of warming is still significant.

              and anthropogenic contributions are a small percentage of global CO2 production

              What is re

              • I'm not surprised that climatological literature is a chorus of global warming anthropogenesis. Climatologists who offer alternative theories get fired (such as Mark Albright [heartland.org]) , retitled (such as Patrick Michaels [grist.org] and George Taylor [kgw.com]), or threatened with one or both.

                This whole issue has become so politicized that any dissenter is viciously attacked, personally and professionally.

                You might do well to watch "Doomsday Called Off" [google.com] to see other scientists' research in beleaguered opposition.
                • Ah yes. When all else false, resort to global conspiracy.

                  When you want to discuss some scientific evidence, let me know. (No, I'm not going to watch a video, but you can summarize it if you like.)

        • The point of my last paragraph in my other response, in case it wasn't clear, was that the costs of making an error aren't symmetric. Even if you ignore the large amount of science which supports the enhanced greenhouse effect, if we cool too much it's easy to make it warmer. But if we warm too much, it's hard to make it cooler. This means we should be concerned more about potential warming than cooling.

          And a potential 3-4 degrees C of warming (and larger in boreal regions like Canada) in 100 years, whic

        • Most european industries know from experience that money spent to reduce CO2 emmission (meaning almost exactly reduce fuel usage) is not lost, but invested in far better conditions than the financial market can promise.
          You may also note that fuel usage usually not only produce CO2 but also various midly toxic chemicals that can cause a local overoccurence of some diseases. Burning fuel as if there was no consequences has so many proven bad consequences that arguing over a not totally proven one is just ...a

    • by Rei (128717) on Wednesday October 15, 2008 @06:07PM (#25390923) Homepage

      Once again, this is why people who don't know anything about a topic shouldn't comment on it.

      Earth's oceans, especially the Pacific, are truly massive heat reservoirs, and changing how they interact with the atmosphere can strongly affect the atmosphere's temperature in the *short term*. In the long term, the planet is still dominated by its radiation balance, of course.

      The linked article was describing, quite accurately, how the early part of this year was in La Nina conditions. El Nino is caused by the weakening or reversal of the Walker circulation (an atmospheric flow around the Equator). The Walker circulation helps encourage the upwelling of cold waters in the eastern Pacific, so El Nino conditions prevent more of this cool water from reaching the surface. As a net change, the equatorial Pacific ends up much warmer on the surface, raising atmospheric temperatures. In La Nina conditions, the situation is reversed; a stronger Walker circulation encourages more upwelling, and thus colder surface (and hence atmospheric) temperatures.

      This has *absolutely nothing* to do with the planet's long-term temperature, which even a six year old looking at a graph could recognize through the year-to-year noise.

      Now, if you *really* want a breakdown of how it ranked (records since 1880), here you go (remember that the first half of this year was in strong La Nina conditions!):

      January [noaa.gov]: 31st warmest
      February [noaa.gov]: 15th warmest
      March [noaa.gov]: Warmest for land on record, 13th warmest for ocean
      April [noaa.gov]: 13th warmest
      May [noaa.gov]: 8th warmest
      June [noaa.gov]: 8th warmest
      July [noaa.gov]: Tied for 5th warmest
      August [noaa.gov]: 10th warmest
      September [noaa.gov]: Tied for 9th warmest

      Spring [noaa.gov]: 7th warmest
      Summer [noaa.gov]: 9th warmest
      January to July [noaa.gov]: 9th warmest

      • by dtjohnson (102237)

        Well, sure, it's not THAT cold...yet. The general idea of global warming, though, is that the carbon dioxide in the atmosphere is trapping heat that would otherwise be radiated into space, and the effect is increasing. Most importantly, the amount of the increased heat being retained should generally be increasing as the carbon dioxide concentration increa and it should be impossible for there to be less heat retained, if the theory is correct. If global temperatures in the sea and air decrease, however,

        • There is, of course, variation and 'noise' in the air and water surface measurements as well as the effects of mixing and circulation but the general idea should one of steadily increasing temperatures. Your list should have 2nd warmest, warmest, 2nd warmest, warmest, etc. rather than 9th warmest, 10 warmest, 8 warmest, etc.

          No. There is quite a lot of interannual weather variation, which you can see in any of the instrumental temperature data sets. The greenhouse effect doesn't predict that every year will break or nearly break the previous year's record in a monotonic increase, and you don't see that in the climate model predictions either. You do see an overall upward trend, but on timescales of a decade or so, there can be considerable short term fluctuation above and below the main trend.

          • by dtjohnson (102237)

            The greenhouse effect doesn't predict that every year will break or nearly break the previous year's record in a monotonic increase, and you don't see that in the climate model predictions either. You do see an overall upward trend, but on timescales of a decade or so,

            From a global energy balance point of view, the amount of heat retained by Earth must increase every year if the theory about atmospheric carbon dioxide significantly reducing heat radiation into space is correct and that retained heat must m

            • Some places colder, some warmer but overall temperatures must increase...every year...all other things being equal.

              All else is not equal. For one, there is substantial variability from year to year in cloud cover, which prevents heat from reaching the Earth's surface (reflected into space). Over the long run, the greenhouse effect wins out, but only over the long run. In addition, there is a lot of variation in how much heat ends up in the ocean vs. stays near the surface; in some years, the ocean takes more and the surface gets less, and vice versa. Finally, heat can move from the deep ocean to the surface and vice

              • by dtjohnson (102237)

                All else is not equal. For one, there is substantial variability from year to year in cloud cover, which prevents heat from reaching the Earth's surface (reflected into space).

                You are conceding, then, that the reflectivity of the cloud cover can vary from year to year. That puts you ahead of many global warming advocates. Isn't it also possible that warmer surface temperatures (which you must admit would be expected with global warming) would lead to increased evaporation, increased atmospheric moisture,

                • by Ambitwistor (1041236) on Wednesday October 15, 2008 @09:02PM (#25393093)

                  You are conceding, then, that the reflectivity of the cloud cover can vary from year to year. That puts you ahead of many global warming advocates.

                  No, it's a well known fact.

                  Isn't it also possible that warmer surface temperatures (which you must admit would be expected with global warming) would lead to increased evaporation, increased atmospheric moisture, and increased cloud cover, thereby increasing reflectivity and providing a global temperature feedback control mechanism?

                  Yes. There are two major cloud feedbacks, one for cloud albedo cooling as you describe, and one for cloud greenhouse warming.

                  Yet, current models either don't account for that or simply assume that reflectivity is constant.

                  That's wrong; dynamic cloud feedbacks are in all modern GCMs.

                  Nevertheless, the CO2 theory of global warming must result in more heat present in the oceans every year.

                  No, it doesn't, for reasons I just stated.

                  Of course, that's not what is observed, which completely undermines the entire simplistic theory of co2-based global warming,

                  As I just said, (1) cloud modulation alters your claim of "monotonic heat increase", and (2) ocean heat observations are not very accurate.

                  but its adherents wave that away as a minor point,

                  That's because there isn't anything yet statistically inconsistent with model predictions.

                  just as they ignore variations in heat originating in the planetary core

                  They're ignored because they've been measured and are utterly negligible, on the order of a hundredth of a degree.

                  and variations in solar output.

                  Those aren't ignored either; there is a large literature of it, and is in fact one of the pieces of evidence supporting CO2-induced warming. Solar output trends are inconsistent with the warming which has been observed.

                  • by dtjohnson (102237)
                    You might say that variations in reflectance are a "well known fact" but the fact is that studies of the effect of reflectance on global warming are relatively recent [universetoday.com] and are not properly accounted for in current models. Certainly, the CO2-causes-global-warming fans ignore it. You claim that the CO2 theory of global warming does not result in more heat present in the oceans every year. Would you concede that the alleged 'greenhouse' effect of CO2 warming occurs every year or do you you claim that the CO2
                    • Re: (Score:3, Insightful)

                      by Ambitwistor (1041236)

                      You might say that variations in reflectance are a "well known fact" but the fact is that studies of the effect of reflectance on global warming are relatively recent

                      Study of stochastic fluctuations in forcing on global warming go back until at least the 1970s; in fact, it was an early competing hypothesis to the greenhouse effect. Hasselmann's 1976 paper is seminal here, although I'm not sure which paper was the first to look at clouds specifically.

                      and are not properly accounted for in current models.

                      It's true that clouds are the least properly modeled aspect of the climate. For prediction that's important; for historical attribution, it's less important, because we've measured it. It's not true that you can replace t

                    • by dtjohnson (102237)

                      Study of stochastic fluctuations in forcing on global warming go back until at least the 1970s; in fact, it was an early competing hypothesis to the greenhouse effect. Hasselmann's 1976 paper is seminal here, although I'm not sure which paper was the first to look at clouds specifically.

                      Did you read the link I provided? "Precision earthshine observations to determine global reflectivity have been under way at BBSO since 1994, with regular observations commencing in late 1997...The low albedo during 1997-2

                    • by dtjohnson (102237)

                      Minor correction: Lord Kelvin actually calculated that the age of the earth was 25 million years old rather than 4,000.

                    • Did you read the link I provided?

                      Yes. As I said, stochastic fluctuations in clouds as related to climate have been studied since the 1970s. Radiometric studies of Earth albedo go back to the 1960s, The Earthshine data is more recent.

                      If you read the paper associated with your link, you find that they don't use the cloud albedo changes to explain long term trends in global warming. Rather, they speculate whether the warming has caused, and will cause, future cloud albedo changes. You might want to read Evan et al.'s followup GRL piece.

                      The historical record shows that global temperatures have swung to great extremes over just the last few thousand years.

                      No

      • Once again, this is why people who don't know anything about a topic shouldn't comment on it.

        Wow, welcome to slashdot, get used to it!

    • Do you truly believe his mission was more than to do some damage to foreign economies? Flying his personal jet to encourage other people not to fly. Encouraging governments worldwide to pay more to reduce CO2 levels, he, ex-vice-president of USA who has done nothing to reduce those levels in his own country while he was in power (Kyoto protocol, anyone?). You call environmentalist, i call hypocrisy.

      Last "Little Ice Age" has ended merely 200 Years ago. It wasn't human-related. Sun-related, most likely. What

      • Last "Little Ice Age" has ended merely 200 Years ago. It wasn't human-related. Sun-related, most likely.

        Sun and volcano related.

        What if the temperature pendulum went that high because of this?

        For one, because solar output has increased very little over the last 50 years, when we saw the most warming. See, for instance, the review in Science by Foukal et al. in 2006.

        We have seen increased sun activity during last decades, now that the sun is calm we see a decrease in global temperatures.

        If you think that the climate responds that quickly and largely to a relatively small change in trend, you're going to have an even harder time explaining the previous 40 years of warming than I mentioned above.

        Sounds pretty logical for me as I still don't think that human influence would be that significant on the global scale.

        Have you calculated the magnitude of the effect? I didn't think so.

    • Re: (Score:2, Informative)

      by kesuki (321456)

      "2008 is the coldest year of the 21st century and output from the sun is declining.
      Maybe Al Gore and his carbon cult followers were...wrong. "

      erm, do you understand that the sun's output isn't declining, but rather is in part of a 11 year cycle? oh yeah, 11 years is an estimate, they vary from 9 year to 14 year variation. no, you don't understand that the number of sun spots is a cycle that can change like the weather, and sun spotless (nearly) years are a common (roughly every 11 years since recorded meas

      • IIRC, some cycles were skipped during Little Ice Age. We might see similar behavior where the increase is insignificant followed by another period of calm sun.

  • by peter303 (12292) on Wednesday October 15, 2008 @05:34PM (#25390303)
    The Mauder Sunspot Minimum [wikipedia.org] in the 17th century has been arguably tied to the Little Ice Age, a cool period. The new 11-year sunspot cycle #24 has been very slow to start as predicted in late 2007. There have been as few as five sunspots in all of 2008. During the active part of the cycle there are up to 150 at a time. The sun is about 0.1% weaker during the cycle minimum. Perhaps this correlates with cooler weather. There are better tools now for tying solar weather with earth climate and maybe someone will find a causal tie.
  • by David Gerard (12369) <slashdot@NOSpam.davidgerard.co.uk> on Wednesday October 15, 2008 @05:57PM (#25390749) Homepage

    I'm sure President Palin will fight back the ice fantastically efficiently, for the good of the economy. You betcha! [today.com]

  • by MarkusQ (450076) on Wednesday October 15, 2008 @06:37PM (#25391421) Journal

    It's important to keep in mind that this isn't a measure of how much ice there is in the arctic.

    The figures they are reporting are sea ice coverage estimates, and typically work as follows: the arctic is broken up into a grid, and for each area of the grid which does not fall on land they ask the question "is >15% of the surface covered with ice?"

    If the answer is yes, it's counted as "ice;" if not, not.

    There are several ways this can give results you wouldn't expect:

    • If one cell of the grid is 85% ice covered and the eight adjacent cells are ice free, this counts as 1/9 of that area being ice. If some of the ice melts and the rest disburses so that the original cell and four neighbors are now all 16% ice covered, it counts as five times as much ice coverage (5/9) even though the total amount of ice went down
    • Ice thickness is totally ignored
    • Land ice is totally ignored
    • Submerged ice is only counted by inference

    --MarkusQ

    • That's true, but it should also be noted that sea ice extent is still a climatically interesting quantity. Non-submerged ice area is closely related to surface albedo, i.e. how much shortwave solar radiation is reflected from the Earth, which obviously relates to how much the Arctic warms (polar amplification). Both sea and land ice contribute, but sea ice is of particular interest because it is more vulnerable to melting than are land ice sheets in the Arctic. This is due to it being situated on relativ

      • Correct, but bear in mind that this isn't a measure of sea ice coverage either; it's a doubly aggregated value that must be taken with a dram of salt water. While it is true that the percentage of sea surface covered with ice is strongly correlated with local albedo, the percentage of sea surface parcels which are covered with more than a certain threshold percentage of ice is much less strongly correlated, especially when that percentage is far from the median. IIRC correctly, using the median value as t

        • Yes, I agree. I hadn't heard of the median/mode weighting that you mention as giving the best fit. Do you know a reference? Thanks.

          • Yes, I agree. I hadn't heard of the median/mode weighting that you mention as giving the best fit. Do you know a reference? Thanks.

            No, it was a heuristic I picked up from a statistician I worked with years ago, and I'm not even certain I've stated it correctly.

            The basic idea is a generalization of the rounding rule. If you have a bunch of values evenly distributed between 0.0 and 1.0 you can approximate their sum by counting how many are >= 5.0 and multiplying by 10. So I see already that I got it w

  • So the volcanos on the Lomonosov and Gakkel ridges shut down. Less steam heating of the bottom of the Arctic Ocean, less ice melts at the top of the ocean.

    And this boggles peoples minds because....?

    • The volcanoes are mostly not under the sea ice, their heating doesn't measurably reach above depths of 1500 meters, and the total heat is nothing compared to what it takes to melt siginificant quantities of sea ice. It's rather ridiculous to claim that they have anything to do with sea ice melting.

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