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Earth Space Science

No, We're Not Headed For a New Ice Age 473

Posted by Soulskill
from the snowboard-stocks-plummet dept.
purkinje writes "Unusual calm in the solar cycle — called a solar activity minimum — has sparked claims that the Sun will cool the Earth, leading us into a new ice age. While Europe did experience a Little Ice Age during a solar activity minimum three centuries ago, the connection between sunspots and climate is a lot more complicated, and it's unlikely this change in the Sun's activity will cool Earth down — or even affect the climate at all. Plus, any cooling that might come from this would be less than the global warming that's been going on. So don't pull out that parka yet; a new ice age seems more than unlikely."
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No, We're Not Headed For a New Ice Age

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  • It is plausible (Score:1, Interesting)

    by Anonymous Coward on Friday June 17, 2011 @12:06PM (#36476596)

    People will believe facts that bolster their preconceived opinions. They will disregard or twist facts that do not.

    I used to believe that CO2 could cause global warming but didn't think too deeply about it. Then they tried to erase the Medieval Warm Period. That got my attention and 'Global Warming' has become a bit of a hobby for me.

    What I can say is that there is junk science on both sides of the debate. There is also good science on both sides of the debate.

    There is plenty of historical evidence that, when there is a long period with few sunspots, there is global cooling. In fact, IMHO, the evidence is a lot more robust for that than is the evidence that CO2 is causing catastrophic global warming.

    History is clear that when the temperature is as warm as it is now, or warmer, people have thrived. When the temperature was much cooler that it is now, humanity has suffered many calamities. I would far prefer a warmer planet to a colder one.

  • by blueg3 (192743) on Friday June 17, 2011 @12:10PM (#36476650)

    This is because people are bad at quantitative analysis. Look, solar irradiance averages about 1366 W/m^2 and a has a variation of about 1 W/m^2 (using a one-year moving average). That's 0.073%. If the Earth's temperature was entirely determined by solar irradiance, then the temperature variation would be about 0.2 C. That is, you'd see an 11-year temperature cycle corresponding to the solar output cycle with temperatures varying +/- 0.1 C from the average over the course of this cycle.

    There. A tiny bit of research on the Internet and some math and you too can put bounds on how much influence sunspot cycles have on Earth's temperature.

    And yes, climate scientists are familiar with this. The sun has been kind of important to climate science since Arrhenius figured out the greenhouse effect in 1896 and used the Stefan-Boltzmann law to estimate the Earth's temperature dependence on CO2.

  • by sribe (304414) on Friday June 17, 2011 @12:11PM (#36476656)

    ...or even affect the climate at all.

    Not going to cause an ice age? OK, fine, that I believe. A significant drop in the source of nearly all heat for the planet not causing a change at all? Well now.

  • by jd (1658) <{moc.oohay} {ta} {kapimi}> on Friday June 17, 2011 @12:27PM (#36476990) Homepage Journal

    Not entirely true. Climate is chaotic in nature and can be likened to the "owl mask" of the Lorenz atrange attractor system, with glaciation being one orbit and inter-glaciation being the other. But if you displace the system too far, the system will lock onto a very different set of strange attractors and very different orbits, none of which are guaranteed to be glacial in nature. The problem with chaotic systems is that you can't ever know what "too much" means in advance, you can only ever know when the system realigns.

  • Wikipedia ignores it (Score:2, Interesting)

    by gr8_phk (621180) on Friday June 17, 2011 @01:08PM (#36477702)

    Who is ignoring solar forcings?

    From the Wikipedia entry on greenhouse effect:

    About 50% of the Sun's energy is absorbed at the Earth's surface and the rest is reflected or absorbed by the atmosphere. The reflection of light back into space—largely by clouds—does not much affect the basic mechanism; this light, effectively, is lost to the system.

    This seems to be a hand waving rejection that increased cloud cover would reduce global temperatures. Since cloud formation can be initiated by con-trails, this seems to me a nontrival thing, but they reject it. If you look at the article on pan evaporation rates, they also downplay (ignore) the fact that sunlight is the primary driver of the evaporation rate - even though some of the references indicate that - and make it sound like a complex dependence on ground level atmospheric conditions. Hence global dimming isn't a real phenomenon.

    Bottom line is that real data gets thrown out whenever a topic gets infected by politics.

  • by pz (113803) on Friday June 17, 2011 @01:16PM (#36477796) Journal

    You're assuming that the irradiance is absorbed linearly as a black body by the earth, rather than driving potentially non-linear effects (clouds, ice caps, etc.). Yes, the model might work for the Moon, or other bodies with little-to-no atmosphere that have rigid surfaces fundamentally unchanged by variations in illuminance, but probably won't be that accurate for the Earth.

    People are also bad at understanding complex effects, as your post shows. The surface temperature of the Earth is determined by insolation and reflectivity (along with atmospheric composition, oceanic current flow, heat from the core, drag from the moon and sun, etc.); you only considered insolation, and tacitly assumed linearity.

    One of the most interesting ideas regarding climate variation is that the albedo (reflectivity) of the earth has a forcing term based on orbital variations; that there is an orbital effect on climate is known. The interesting part comes from *why* --- a colleague of mine published a paper in Nature suggesting that it is because as the Earth orbits the sun, it sweeps out the dust in its lane, and variations in the orbit translate to variations in how much dust gets accreted. He had some very nice core sample data of cosmogenic dust accretion over geological time periods that was, to my eye, quite convincing. Changes in the dust accretion, it was suggested, change the albedo by seeding clouds: more dust means more rain, more rain means less cloud cover, fewer clouds means reduced albedo.

    Exactly the same ideas (variations in orbital position and sweeping out the orbital lane) are what allow astronomers to predict how strong a given meteor shower will be each year. Meteor showers are just accretion of somewhat larger grains of dust.

  • by exabrial (818005) on Friday June 17, 2011 @01:16PM (#36477798)
    So we don't know what effect sunspots have, but we're absolutely, positively, 100% confident that human caused global warming is happening and would counteract it anyway, because we've completely proven that's true.

    Here's the thing, it's not that I don't believe it, because there is evidence _something_ is happening. It's that one, no matter what, the attitude of warmers is 'it can't be disproved.' The red light in my head for 'apply critical thinking here' is going off, but the minute I open my mouth to ask a question I'm berated.

    In conclusion, I don't feel sorry for your cause and I'm buying a Ford Explorer on the way home. If supporters would change their attitude, maybe they'd win a few more. I'm completely turned off by the polarizing, cliquish, elitist, school-girl attitude.
  • by ElektronSpinRezonans (1397787) on Friday June 17, 2011 @01:32PM (#36478040)
    When I read a paper in a good journal, I trust that it has been peer reviewed and any over-interpretation were addressed prior to publication. I know because that's how my papers were published. It doesn't always happen of course, scientists are usually too eager to create a story, but regardless, I trust the raw data collected in a study. Pretty much the only way to dispute data is to accuse them of forgery. In climate science, where everyone is looking over everyone's shoulder, it'd be pretty stupid to forge data...

    So, I'm afraid I disagree, that's not how science works. More to the point, what scientists consider "Science" and what is propagated to the public as "Science" are different, thus being skeptical are different concepts for both parties. I am skeptical of the "Discussion" section of a paper, and the general public should be skeptical of everything they are presented as Science.
  • by Anonymous Coward on Friday June 17, 2011 @02:21PM (#36478660)

    Or better yet Comrade, prosecute them in the Hague for crimes against humanity for daring to be skeptical about it. Maybe we could outsource it to the PRC, they seem to be pretty good at that kind of thing; hey, the prison thing would be easy for them to manage. $0.40 for the .38 cal bullet...

    Hey, we can even call them Deniers, to build an association between Holocaust Deniers and Climate Change Deniers. That'll make it easier to round them up and send the out for re-education or for the tough cases "Carbon Sequestration;" (now, where did we leave all that Zyklon B?? I just saw it...) for the Father La.. errr, for Mother Earth!!

    Oh, wait, (no) [dailykos.com] (one) [sullivan-county.com] in the (west) [senate.gov] would want such a thing! I'm sure they're just Rethuglicans... uhm, never mind.

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