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Robot Sub Finds Surprisingly Thick Antarctic Sea Ice

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  • #76
    Originally posted by Catholicity View Post
    in the late 90's early 2000's it was global warming now its climate change......
    I think you are trying to imply that scientists are moving the goalposts here. This is not the case, as far as I can tell. Global warming has certain predicted effects, and the actual heating of the planet is perhaps the least visible, since we're only talking about a degree or two worldwide over a century. But even very slight overall warming causes side-effects of a wide variety - changes in ocean and air currents, for example, which bring unusually cold weather to nearly as many places as they bring unusually warm weather. Such things as floods and droughts aren't obviously connected to global temperature changes of fractions of a degree.

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    • #77
      Originally posted by Catholicity View Post
      CFC's were taken out in the 80's for fear of Global cooling,the now rebuilt hole in the ozone then in the late 90's early 2000's it was global warming now its climate change......
      Also, please see the graph i posted on the previous page.
      "Any sufficiently advanced stupidity is indistinguishable from trolling."

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      • #78
        Originally posted by shunyadragon View Post
        Actually the coming 'Ice Age' is likely inevitable, but were talking maybe ~20,000 to 40.000 or more in the future.
        Keep in mind that the sun is actually increasing it's energy output. 20 to 40 k years may be enough to offset this inevitable ice age. Not a claim just a question.
        Micah 6:8 He has told you, O man, what is good; and what does the LORD require of you but to do justice, and to love kindness, and to walk humbly with your God?

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        • #79
          Originally posted by TheLurch View Post
          Also, please see the graph i posted on the previous page.
          science.jpg
          The first to state his case seems right until another comes and cross-examines him.

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          • #80
            Originally posted by Jedidiah View Post
            Keep in mind that the sun is actually increasing it's energy output. 20 to 40 k years may be enough to offset this inevitable ice age. Not a claim just a question.
            By then most humans might live off earth in space colonies. Earth might become largely a nature preserve. If, that is, we have not nuked or polluted ourselves into extinction by then.
            The greater number of laws . . . , the more thieves . . . there will be. ---- Lao-Tzu

            [T]he truth Iím after and the truth never harmed anyone. What harms us is to persist in self-deceit and ignorance -ó Marcus Aurelius, Meditations

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            • #81
              I might need to read a bit more as the memory of a young child can cross a bit..... I was my daughters age and younger (sheesh time flies)
              A happy family is but an earlier heaven.
              George Bernard Shaw

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              • #82
                Originally posted by shunyadragon View Post
                Actually the coming 'Ice Age' is likely inevitable, but were talking maybe ~20,000 to 40.000 or more in the future.
                Probably not inevitable at this point. Absent the human effect, yes; that's the likely order of time to the next ice age. (There's been a interesting set of papers with different proposals for the time scale, but it's probably academic.)

                The human impact is a spanner in the works; the long range impact of an enhanced greenhouse effect is very likely to have prevented the next ice age from occurring at all, even if we manage to put strong limits on future emissions and limit the consequent extent of warming over the next century. If we overheat the planet in a big way by continuing to burn as much fossil carbon as we can, then the whole ice age cycle thing is likely to stop for quite a long time; maybe several hundred thousand years.

                In brief: long range estimation of a perturbed climate indicate that the usual triggers for the next ice age won't be enough; we've ALREADY prevented the next ice age. This long range isn't a long range climate projection as such; it's a long range CO2 projection (which is on much more solid quantified grounds.) Since raised CO2 levels persist for a long time, they become a factor to compare with the orbital forcings thought to precipitate ice ages. If CO2 levels are significant raised, a glacial epoch can't get started.

                Typically, discussions of global warming and human driven climate change focus on the next 100 years. The impact of a changed atmosphere lasts much much longer than this.

                A good book on this is Deep Future, by Curt Stager (2011). Subtitled: "The next 100,000 years of life on Earth". Online resources include This review at Science magazine, and Stager, C. (2012) What Happens AFTER Global Warming? in Nature Education Knowledge 3(10):7

                Originally posted by Jedidiah View Post
                Keep in mind that the sun is actually increasing it's energy output. 20 to 40 k years may be enough to offset this inevitable ice age. Not a claim just a question.
                The answer to this is the effect of increasing solar output is way way too small to offset the next ice age. The Earth has for the last 2.8 million years or so been in what it called the Quaternary period, which is marked by cycles of advance and retreat of glaciers, on cycles of about 40K or 100K years. (A roughly 40K year cycle in the early part of the Quaternary, and roughly 100K cycle in the last million years.) There have many many many such cycles, and each cycle involves an "ice age" and a short interglacial warm phase (like our current Holocene period). Absent something drastic, these cycles of glaciation and recovery can be expected to continue for a long time yet.

                However, as noted, the "something drastic" has already happened, and glacial cycles have most likely had a hiccup for the next hundred thousand years, at least.

                You do touch on a very interesting point, however!

                Solar changes have their impact on a scale of more like 100 million years; and it has been a mystery as to why Earth's climate has been so comparatively stable on such scales with the Sun getting brighter all the time. This is called the "faint young sun paradox". Google it; it's a well known puzzle in science.

                The answer turns out to be carbon dioxide again; carbon dioxide levels in the atmosphere have fallen as the Sun has got brighter, and so the two factors (roughly) cancel out. There's a fairly well supported hypothesis about this phenomenon. Specifically, that this is no accident, but is rather the consequence of a very long range "slow" negative feedback. Hotter temperatures tend to result in increased weathering, and a draw down of carbon from the atmosphere to carbonates into geological reserves. The specifics mean that there is a characteristic temperature at which the draw down matches the comparatively steady output of carbon dioxide again from geological carbonate reserves through volcanic activity; and the feedback tends to drive temperature towards that sweet point, for a whole range of very different solar inputs. The effect is really really slow however. It's enough to keep up with the slow rate of increased solar output, but not enough to be a big factor driving swings in climate as occur from time to time for many reasons.

                Cheers -- sylas
                Last edited by sylas; 12-09-2014, 05:14 AM. Reason: spelling

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