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Changes In Earth's Orbit Were Key To Antarctic Warming That Ended Last Ice Age 180

Posted by Soulskill
from the i-blame-kepler dept.
vinces99 writes "For more than a century scientists have known that Earth's ice ages are caused by the wobbling of the planet's orbit, which changes its orientation to the sun and affects the amount of sunlight reaching higher latitudes, particularly the polar regions. The Northern Hemisphere's last ice age ended about 20,000 years ago, and most evidence has indicated that the ice age in the Southern Hemisphere ended about 2,000 years later, suggesting that the south was responding to warming in the north. But new research published online Aug. 14 in Nature (abstract) shows that Antarctic warming began at least 2,000, and perhaps 4,000, years earlier than previously thought."
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Changes In Earth's Orbit Were Key To Antarctic Warming That Ended Last Ice Age

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  • by Anonymous Coward on Wednesday August 14, 2013 @04:15PM (#44567979)

    It's Cavemanthropogenic Global Warming, if you want to get technical.

    • Re: (Score:2, Informative)

      by i kan reed (749298)

      Well, there's not unreasonable evidence that early human slash-and-burn farming caused a reduction in important negative feedbacks (vis-a-vis forests) and the carbon cycle. But that has basically negligible effect compared to the rates of change (and rates of change of rates of change) seen since 1800.

  • by Anonymous Coward

    Allow me to break the ice with the first post

  • Oh god... (Score:1, Insightful)

    by Anonymous Coward

    Cue unrelated arguments about modern global warming... time to flee Slashdot for a few hours....

  • by Anonymous Coward on Wednesday August 14, 2013 @04:28PM (#44568063)

    But warming is caused by man.

    Got it.

    • So, you dismiss some current science but want to make cute quips about how other current science backs you up?

      If you have an actual point to make about how hundreds of climate scientists are wrong, please cite your data. Otherwise you are just insinuating that hundreds of educated people are missing something that you see... as opposed to hundreds of educated scientists knowing something about how and why these occurrences are different and can have different causes.
      • The fundamental hypocrisy here is one that is necessary to the scientific method. You must simultaneously be willing to accept that some components of a branch of study are flawed enough to warrant whatever hypothesis, experiment, or observation you are doing, while still believing in the fundamental soundness of the scientific method, and the general accuracy of most results, which form the basis of your own study.

        This is a case where they're just being intentionally obtuse, and have nothing interesting t

    • by dywolf (2673597)

      warming is caused by many things.
      no one has ever said that only man causes it.

      however all of those things cause warming over a very very long time scale. except man.
      which is why the very very fast warming we've seen is attributed to man.

      • Re: (Score:2, Troll)

        by rgbatduke (1231380)

        You might want to look at two things. One is the actual thermal record over geological time, which shows intervals of extremely rapid natural warming and cooling. Second, you might want to consider the fact that much of that record is essentially smeared out by imprecision in the proxies used so that one is comparing two different kinds of averages -- one averaged over a very short time interval, and another where the average might well be over a period longer than the entire time we have had thermometers

        • by cusco (717999)
          Previous "intervals of extremely rapid warming and cooling" were centuries and millenia long. We're seeing changes over the period of decades, and ice cores from Antarctica show no similar pattern for at least the last 850,000 years. If you look at the timing of the 'Little Ice Age' you may notice that it starts almost immediately after the Black Death killed off 1/3 of everyone from India to Iceland and forests re-covered eastern Europe, sequestering huge amounts of CO2. I would be surprised if your "un
          • I've never run across your suggestion that the after effects of the Black Death might have caused the Little Ice Age before; it's an interesting idea. I do have two questions however. First, is this just speculation on your part or are you offering it as an explanation of what happened. Second, if you do think this is a serious theory, do you have any evidence other than the timing? I'm not trying to shoot you down, here, but if you have any more information, I'd like to see it.
            • From:
              http://en.wikipedia.org/wiki/Little_Ice_Age [wikipedia.org]

              Decreased human populations

              Some researchers have proposed that human influences on climate began earlier than is normally supposed and that major population declines in Eurasia and the Americas reduced this impact, leading to a cooling trend. William Ruddiman has proposed that somewhat reduced populations of Europe, East Asia, and the Middle East during and after the Black Death caused a decrease in agricultural activity. He suggests reforestation took place,

              • Thank you; that was very interesting. From what the article says, lower human population caused by the Black Death and resulting reforestation is one of several possible causes, but there's currently no way to tell just which cause or causes are responsible. Still, it's something to think about.
                • by cusco (717999)
                  I first saw this in an article in Scientific American about a decade ago (won't bother searching for it, as it's behind the paywall) titled something like, "Did Agriculture Stop The Ice Age?" This was when Sci Am articles were still long and full of graphs and charts, one of which showed the extremely regular inter-glacial cycles of the last half million years, the exception being the current one. CO2 and temperatures started dropping on schedule (well, as "on schedule" as a cycle 10,000 years long can be
          • So you're saying that the Bern model for CO_2 sequestration is wrong, then? I don't think we know enough to say that it is right OR wrong yet, and won't for some time yet, but sure, it might be wrong.

            However, you need to actually do the numbers before you conclude that killing off 1/3 of everybody from India to Iceland might have sequestered "huge amounts of CO_2" and you might point out some evidence that this occurred in the various CO_2 proxies before basically making something up to explain something t

            • by cusco (717999)
              some evidence that this occurred

              The economy of that whole section of the world collapsed, farmland away from population centers was abandoned and reverted to forest. Travelers reported that a squirrel could travel from Vienna to Warsaw and never have to leave the trees, a region that was heavily farmed both before and after the population collapse.
              • Heavily farmed? You might take a glance at the population of the world then and now. I'll help:

                http://en.wikipedia.org/wiki/World_population_estimates [wikipedia.org]

                As you can see, even though the black plague may have killed 1/3 of the world's population, it didn't kill them all at the same time, and it isn't even clear that the world's population ever actually receded during the events, at least according to this table (which also exposes a fundamental limitation -- look at the spread in estimates for t

        • Any reputable climatologist will tell you the resolution on ancient climate reconstructions is nowhere near fine enough to pin things down to decades. The ancient climate is reconstructed by interpolating samples taken centuries apart. This article is a good example, past studies indicated the south lagged the north by 2kyr. That didn't make sense from a physical POV but that's what the sum of the evidence was telling the researchers. To say more than what the evidence is telling you is speculation, not sci
          • Seriously? There is a 0.4 C spike from 1910 to 1940, compared to 0.6 C from 1970 to 2000, and you think that the extra 0.2 C is sufficient evidence of runaway anthropogenic global warming, given a non-anthropogenic spike 2/3 as large in the only two samples of spikes we have in the moderately reliable instrumental record e.g. here: http://commons.wikimedia.org/wiki/File:Instrumental_Temperature_Record.png [wikimedia.org]?

            Note well that I am not claiming that the latter spike is or isn't natural. I'm asserting that the i

    • But Hiroshima was caused by men.

      Got it.

  • by NotQuiteReal (608241) on Wednesday August 14, 2013 @04:31PM (#44568075) Journal
    All that ice on the poles made the Earth all wobbley, which led to Bad Things. We should de-ice the planet, as a precaution so it doesn't happen again!

    I mean, you don't let ice build up on your roof, in your freezer, or on airplanes... ice is always bad unless it is in my drink!
    • by Darinbob (1142669)

      More margaritas for everyone, to save the planet!

    • by roc97007 (608802)

      All that ice on the poles made the Earth all wobbley, which led to Bad Things. We should de-ice the planet, as a precaution so it doesn't happen again!

      I mean, you don't let ice build up on your roof, in your freezer, or on airplanes... ice is always bad unless it is in my drink!

      Hmm. So these orbital wobbles... are they nature's defrost cycle?

    • by msauve (701917)
      Maybe we just need ice at the equator. Ice-9 [wikipedia.org], baby!
  • by sl4shd0rk (755837) on Wednesday August 14, 2013 @04:44PM (#44568171)

    FTFA: "Changes in Earth's orbit today are not an important factor in the rapid warming that has been observed recently...Earth's orbit changes on the scale of thousands of years, but carbon dioxide today is changing on the scale of decades so climate change is happening much faster today."

    • by iggymanz (596061)

      you commit the fallacy of asserting the consequent

      • by Anonymous Coward

        Parent post commits a fallacy of equivocation, if I read its interpretation right. If not, then there is no fallacy at all. Either way there is a distinct lack of either logic or reading skill present. The post also lacks punctuation and a failure to discern the difference between 'affirming' and 'asserting'.

        2/10

        Would not read again.

    • by tlambert (566799)

      FTFA: "Changes in Earth's orbit today are not an important factor in the rapid warming that has been observed recently...Earth's orbit changes on the scale of thousands of years, but carbon dioxide today is changing on the scale of decades so climate change is happening much faster today."

      Yeah, I read that part too, and it's the only part of the article that bothered me. It was something of an unnecessary sensationalist jab in an otherwise informative article. Had they left that last sentence off, it would not have been any less informative, without dragging in T. J. Fudge's poke in the eye of the anthropogenic global warming controversy. Anything to bait the clicks, I suppose...

      • by Gavrielkay (1819320) on Wednesday August 14, 2013 @05:10PM (#44568401)
        Or, it was a (partially) successful attempt to deflect the rash of comments about how their research on the previous ice age must invalidate lots of other research on current climate change.
      • by Anonymous Coward

        It was something of an unnecessary sensationalist jab in an otherwise informative article. Had they left that last sentence off, it would not have been any less informative, without dragging in T. J. Fudge's poke in the eye of the anthropogenic global warming controversy.

        Right, because no one would say, this [slashdot.org] or this [slashdot.org] which were both modded up. The news article is pretty bad, because Vince Stricherz confuses ice age with glacial. The Nature article is about the end of the last glacial [wikipedia.org] period, not the end of the last ice age. We're still in the last ice age, so the subject line is obviously stupid.

      • The funny part is we're in a cooling trend, and the "Carbon Dioxide" explanation was "Global Warming" because of "The Greenhouse Effect". Now that it's not getting hot, it's "Climate Change" but we keep the same explanation and everyone treats it like the same guy with a new haircut and we all know all about the dude. Makes for hilarious stupidity.
        • Re: (Score:2, Informative)

          by Anonymous Coward

          Please, before you post anything on this topic, go to this site [skepticalscience.com] and check if it hasn't been debunked. By endlessly repeating long [skepticalscience.com]-discredited [skepticalscience.com] views, you're only adding noise to the discussion.

        • by riverat1 (1048260) on Wednesday August 14, 2013 @09:20PM (#44570283)

          What's really funny is all the people who say we're in a cooling trend lately when the warmest year on record was 2010. All I can say is enjoy it while it lasts, I doubt you'll still be able to say that in 2020. The greenhouse effect is still in effect.

          • There was a Russian scientist who took that bet in 2000 and won. Are we there again? Can I bet you $1000 and win?

            The charts are showing me a 0.8C movement since 1900, which doesn't seem to be correlated to anything interesting. CO2 levels are strange--I'd like to see a chart of industrial CO2 output and the INTEGRAL of CO2 output (i.e. total CO2 output since baseline), because warming would tend to make CO2 less soluble and thus CO2 would emit from the oceans (or dissolve less). That means that CO2 out

            • Uh, not to quibble, but Fahrenheit is no more "arbitrary shite" than Celsius. The Fahrenheit zero is the freezing point of salt water vs the freezing point of fresh water for Celsius. The 100 point for Fahrenheit was supposed to be human body temperature. As it turns out, his thermometers weren't very good, so he got that end slightly wrong. 98.6 was supposed to be 100. Admittedly, "normal" human body temperature varies quite a bit more than Fahrenheit knew, so as a choice of where to peg his scale, it

              • Salt water, wonderful! How much salt in the water?!

                It's more complicated than that, and it's based on a scale that's rather arbitrary with water boiling at 60 degrees. Farenheit multiplied all the numbers by 4 and recalibrated.

                • As I recall, sea water, specifically. The people who cared the most about the low end of the temperature scale at the time were mariners. When the ocean would start to freeze was important to them.

                  Also not a very good choice for pegging a scale, but what do you want. It was a long time ago.

    • by Arker (91948)

      Ah yes, the requisite recitation of faith.

      And the rest of this is horribly confused. They talk about 'orbit' when they mean 'rotation' (as in around the poles, not around the sun) and they keep talking about an ice age when they are referring to an individual glaciation.

  • I'm not surprised that they happen over time. Has anyone detected a solidly provable shift in modern times?

    • "Solidly provable" isn't a definable term. If you want hard evidence, set hard criteria. Should you do so, I think people might be able to comply.

      • The thing is, I don't actually care that much. I'll leave the specifics up to the people in that field.

  • by VinylRecords (1292374) on Wednesday August 14, 2013 @04:48PM (#44568207)

    Maybe the earth's orbit changes right now are because there are too many people living in one area and they are weighing down the earth like a seesaw? Like if too man people live on one side of an island the island tips over?

    http://www.youtube.com/watch?v=cesSRfXqS1Q [youtube.com]

  • by Anonymous Coward

    Do they mean orbit (around the Sun) or revolution (around the Earth's axis)? I know the Earth's revolution has changed quite a bit in the past, but I thought the orbit was pretty stable. The use of the term "wobble" also leads me to believe they are talking about the revolution of the Earth, and not it's orbit.

    • They also talk about the wobble changing the amount of solar radiation incident on higher latitudes which also implies that they were really talking about the inclination of the axis of rotation, not changes in the orbit. Never heard of orbit wobble but it's well known that the Earth "wobbles" somewhat in a way that changes the inclination of the axis of rotation.

      Cheers,
      Dave

    • by riverat1 (1048260)

      Both the revolution of the Earth and its orbit around the Sun change over time. The changes in the orbit are driven by interactions with the gravitational fields of other objects in the solar system, primarily Jupiter and Saturn.

    • by hutsell (1228828)

      Do they mean orbit (around the Sun) or revolution (around the Earth's axis)? I know the Earth's revolution has changed quite a bit in the past, but I thought the orbit was pretty stable. The use of the term "wobble" also leads me to believe they are talking about the revolution of the Earth, and not it's orbit.

      Trying to decipher what was happening in both the summary and the article was difficult for myself. The lack of clarity seems to be due to the article's informal explanation; their not being concerned about the accepted definitions of the terms they were using. I don't know if it was laziness or confusion on their part or my understanding about present day astronomy.

      The original article in Nature probably does a better job.

      Although I haven't seen the Nature article (due to the payed wall), I suspect it

  • It's too damned hot. Let's all start jumping up and down, start the Earth a rockin' and induce an ice age.
  • by sandbagger (654585) on Wednesday August 14, 2013 @05:45PM (#44568635)

    Relax, Jor-El.

  • I thought the last ice age was in the northern hemisphere,(Europe, North America) not Antarctica.

  • This whole global warming because of mans activities just took a hard nose dive into concrete.
    • by riverat1 (1048260)

      Dream on.

  • by dtjohnson (102237) on Wednesday August 14, 2013 @06:58PM (#44569281)
    "For more than a century scientists have known that Earth’s ice ages are caused by the wobbling of the planet’s orbit.

    There are so many blatant errors in just this one sentence that it's publication is astounding. First, the Earth is currently in the middle of its 5th "ice age," the "Pliocene-Quaternary glaciation," (which began 2.5 million years ago) and what the article calls 'ice ages' are termed by real scientists to be "glacial periods" within the current ice age. The Earth is presently in what is called an "interglacial period" and the next "glacial period" is likely to begin within the next 1,000 to 2,000 years. Next, there is certainly no consensus that either the Earth's "Ice Ages" or "Glacial Periods" are caused by wobbling of the planet's orbit. General consensus by scientists is that both ice ages and glacial periods within those are caused by a variety of factors including atmospheric changes, solar changes, changes in the position of tectonic plates which affect ocean circulation, variations in the Earth's orbit (which are currently considered more likely to affect glacial and interglacial cycles rather than to initiate or end ice ages), and volcanism. In short, TFA is utter bullshit.
    • Oh please.

      First off, there is a general sense and a scientific sense definitions. The world has less methane and CO2 then when the dinosaurs were around and the atmosphere was thicker so of course the world is much colder.

      We wont ever leave the scientific definition of an ice age until the sun expands as a result.

      In a general sense we are out of an ice age. In the real world only scientist use such definitions as glaciation only happens in a few spots in the world today. Ice only happens in the winter typic

  • I believe Hapgood's crust-displacement theory explains the climate change at the turn of the ice age better than orbital wobble.

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