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Earth Science

Little Ice Age: It Was Not the Sun 375

vikingpower writes "The Little Ice Age, lasting from the end of the Middle Age into the 17th century, may very likely have been caused by the combined effects of four major volcanic eruptions and increased sunlight reflection by increasing sea ice, the so-called Albedo effect. ... The University of Boulder has a press release with maps and photographs. Bette Otto-Bliesner, one of the scientists behind the 'volcano + sea ice' thesis, fields an earnest warning against drawing conclusions too quickly from this research: 'I think people might look at the Little Ice Age and think that all we need to save us from rising temperatures are some volcanic eruptions or the geo-engineering equivalent [...] But when you see what happened when global temperatures dropped by just one degree and you look at current predictions of six or seven degree increases for the future, you realize how precarious things are for life as we know it.'"
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Little Ice Age: It Was Not the Sun

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  • by colinrichardday ( 768814 ) <> on Monday February 06, 2012 @10:14PM (#38949183)

    Not the University of Colorado at Boulder?

    • by FatdogHaiku ( 978357 ) on Tuesday February 07, 2012 @01:03AM (#38950053)
      No, the University of Boulder...
      OK, so maybe it is just a guy sitting on a large rock...
      What's your point?
  • Of course. (Score:2, Informative)

    by Anonymous Coward
    After 5 billion years, the sun is basically in steady state. I would not expect to see fluctuations over the type of timescales that human beings exist on. Yes, the sun is slowly getting hotter, but that's a long term trend.
    • by Geoffrey.landis ( 926948 ) on Monday February 06, 2012 @10:50PM (#38949421) Homepage

      After 5 billion years, the sun is basically in steady state. I would not expect to see fluctuations over the type of timescales that human beings exist on....

      the sun is pretty steady, a middle-aged star, but there are still some small variations in solar intensity. The hypothesis was that the Little Ice Age was correlated with the solar "Maunder Minimum," a 75-year period during which the sun had no sunspots (and hence presumably was about 0.07% lower in brightness).

      What this work did was put a good date to the start of the Little Ice Age; using radiocarbon dating to determine when the plants killed by the advancing glaciers died... and the dating shows the Little Ice Age began well before the Maunder minimum. The Maunder minimum didn't cause it, very definitely.

  • by Anonymous Coward on Monday February 06, 2012 @10:15PM (#38949193)

    No doubt this item will produce reasoned, well mannered discourse in droves! Pop some popcorn, enjoy the highbrow debate!

  • I fail to see how a 1 degree average change can make any significant difference (In Phoenix, if one day the temperature ranges from 80-110 degrees F, and the next day it's 81-111 degrees F, you won't notice).

    That said, one thing that's consistently missing is how much the standard deviation of the temperature changes. You might not notice a 1 degree standard deviation shift, but you will notice a 5 or 10 degree standard deviation shift.

    Why is this data never present in global warming arguments? Any climatol

    • by ceoyoyo ( 59147 )

      "I fail to see how a 1 degree average change can make any significant difference"

      If every day is 1 degree warmer or colder (just +1 degree, everywhere, no variation), you might not notice on any particular day, but you might notice that spring comes earlier or later, and you might notice your feet getting wet (or dry) because more ice is melting (or accumulating) at the poles and high altitudes.

      What standard deviation are you looking for? Between locations on the planet? Daily? Monthly? Yearly?

    • by mellon ( 7048 ) on Monday February 06, 2012 @11:25PM (#38949603) Homepage

      They do talk about it. You just (evidently) don't listen.

      Global temperature increase shifts the atmospheric circulation cells, so that they land in different places. It shifts the jet stream, so that weather is carried to different places. It shifts oceanic currents; there's a big concern that global warming may actually result in a major drop in temperatures in northern Europe. There are many factors that decide what the temperature will be outside your house today; global warming is not the largest factor by a long shot. But where the Hadley Cells, Ferrell Cells and Polar Cells land has a big effect on the weather you experience, and that _is_ affected by global temperature increases in the one degree range. These effects aren't necessarily temperature increases; they are just as likely to be more energetic storms, or droughts, or floods.

      However, it's also worth noting that 1 degree is currently considered a fairly unrealistic best-case scenario, because since we started trying to take some weak action to address Global Warming, China seriously ramped up the amount of coal they're burning, so atmospheric CO2 levels are going up faster than predicted.

    • How much difference did the average of 1 degree of temperature drop during the Little Ice Age make? What if the same level of difference occurs with 1 degree of temperature rise?

  • by tom229 ( 1640685 )
    A much bigger problem is that western economies, having their medium exchange controlled privately, rely on perpetual (and infinite) economic growth to avoid deflation.

    The second more important issue is that the west is continually building their economy to rely on an infinite (and cheap) supply of oil when it's quite clearly a finite commodity.

    Fix these two world collapsing issues first.. and then worry about whether the planet's getting a little bit warmer or not.
    • A much bigger problem is that western economies, having their medium exchange controlled privately, rely on perpetual (and infinite) economic growth to avoid deflation.

      That's not right. You can have inflation any time you want it by printing more money. It might have to be a lot, but if you are diligent enough, you can do it.

  • by Anonymous Coward on Monday February 06, 2012 @11:04PM (#38949501)

    ...something catholic church would disapprove of.

  • by Anonymous Coward on Tuesday February 07, 2012 @12:48AM (#38949995)

    The original article is about the Little Ice Age primarily, and the only tie-in is the comment warning against relying on volcanoes to save us from warming / geoengineering man-made "volcanoes" to fix warming.

      But, ok, you want to ask the question "is it actually warming?" I'm a climate scientist-ish, I'll throw in a line. I recommend for it's superb evidentiary support for the theory of anthropogenic global warming (a.k.a. climate change).

      Yes - we have ample data demonstrating that it is warming, not only in the air but in the surface waters of the ocean (water absorbs some of the heat, it turns out - if only it would absorb more of it!). We have really really obvious evidence (seriously, just look at the satellite pictures) of dramatic summer sea ice loss. The troposphere (where we live - where our weather happens) has warmed about 1.3 degrees F over the last 100 years. This might not sound like a lot, but just integrate 1.3 degrees over the whole planet, and you're talking about a significant amount of energy.

      The stratosphere has cooled up to 6 degrees Celsius (yeah, that's right, mixing up the units) in some places, and higher atmospheric layers have cooled even more. Now, you might ask, why the cooling - this is supposed to be global WARMING, right? The mechanism behind stratospheric cooling is a bit complex, but think about it this way: Greenhouse gases (GHG's) trap more heat (absorbed and re-radiated long-wave energy) in the Troposphere (the lowest layer, where weather happens) than we would otherwise have. If that extra heat weren't trapped in the lower atmosphere, it would have to go somewhere else, right? So where would it go? It turns out, it would go back into space or, more importantly, into the upper layers of the atmosphere (stratosphere, mesosphere, ionosphere). Essentially, the GHG's play favorites with the atmosphere - they give the lowest layer more heat while depriving the higher layers of their ordinary allowance.

    Incidentally, this phenomenon allows us to distinguish GHG-driven heating from sun-driven heating. If global warming were caused by the sun alone, the temperature would increase in all layers of the atmosphere - the sun doesn't play favorites.

    But wait, how do we know it's people? Physics tells us CO2 absorbs long-wave radiation (and then re-radiates that energy in all directions). Simple energy balance calculations tell us that without CO2 and other greenhouse gases (but mostly the CO2, as it is slower to enter/leave the atmosphere than H2O) the earth would be too cold to support most life forms. Over and over again in Earth's long history, higher concentrations of CO2 are associated with higher temperatures (the very early Earth was very warm, despite a weaker sun - this is known as the Faint Young Sun paradox - but greenhouse gases were more abundant). We're pumping this gas into the atmosphere with careless abandon, and we can measure and observe that much of it stays there (removing CO2 from the atmosphere permanently by natural processes takes a loooong time). Even if we didn't measure warming and we couldn't measure CO2 (did I mention we can measure warming and CO2? We do it all the time) the laws of physics and the principles of chemistry allow no other possible conclusion than a future of warming (for most of us) and cooling (for anyone unfortunate enough to be stuck in the upper atmosphere).

    Sorry for the long post. Also, don't think for a minute someone does serious climate science without asking the questions "are we sure we know what we know?" or "are the computer models any good, like, at all?" about 3 times before breakfast. Seriously, people, we're pretty smart apes, this isn't "too complicated" or "too difficult" for us humans to figure out.

The closest to perfection a person ever comes is when he fills out a job application form. -- Stanley J. Randall