AGU Fall Meeting 2013

Our understanding of future Arctic change is informed by the history of past changes, which often have been both large and abrupt. The well-known ice-age events such as the Younger Dryas show how sea-ice changes can amplify forcing to produce very large responses, with wintertime sea ice especially important. These changes are increasingly seen to have played a central role in the ice-age cycling through their global impact on CO2 storage in the deep ocean.

The Heinrich events reveal processes of ice-sheet/ocean interaction, some of which are being played out in Greenland and Antarctica now, and which may have large future effects on sea-level rise. The paleoclimatic record plus physical understanding greatly reduce the worst worries about instabilities from methane stored in cold places, but tend to support a role in amplifying future warming.

Overall, the very large impacts of past Arctic changes, and the likelihood that future changes under business-as-usual fossil-fuel emissions will be unprecedented in combined size and speed, raise important questions.
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  • Scott Rankine 1 year ago

    There are clearly some remarkably misinformed people commenting on this
    talk. Man made climate change (global warming) is indisputable hard
    science. Its also getting progressively worse year after year. Just accept
    it and move on

  • tom hood 1 year ago

    Keep dening fools

  • David Rager 1 year ago

    This is the cycle that mankind should be increasingly worried about:
    Rise in CO2 and resulting rise in temperatures.
    Melting of ice and 200+ foot rise in sea levels.
    Reduction in the temp difference between the poles and the equator and
    resulting slowing of the ocean currents.
    Reduction in the level of oxygen in the oceans resulting in anoxic oceans.
    Growth of H2S producing bacteria and resulting poisoning of the atmosphere.
    Increased temperatures releasing more methane into the atmosphere (25 worse
    as a greenhouse gas than CO2) and more poison into the air.

  • jimbo16720 1 year ago

    There have been numerous ice ages and heating before we started burning
    fossil fuels. Seems pretty dumb to spend money on something we can’t
    control like mother nature. To spend trillions of dollars on something you
    can’t control and has been happening over again for millions of years is
    DUMB. Just like all the stupid studies the government spends our tax money

  • Dave Juszczyk 1 year ago

    Can we please stop giving these people more credit than they deserve.
    Scientists are skeptics, continually questioning and hypothesizing and
    testing. These people are deniers, there is no scientific basis for their
    skepticism. This cartoon sums it up pretty well:

  • Rick Carter 1 year ago

    There are HUGE dragons out there, but for the most part the geologic record
    doesn’t reveal this, because the rate of climate change today is virtually
    unprecedented, and that can and WILL make ALL the difference in the end. So
    I would STERNLY warn the world against over reliance upon the geologic
    record when it comes to deciding what to do or not to do, and included in
    that is when. Having said that, I am just going to quietly turn and walk
    away now, because virtually no one has ever really wanted to hear what I
    personally have to say. Have fun, everyone! – Rick Carter

  • John Callahan 1 year ago

    Does it really matter if it’s the sun, us or geothermal? The Earth “is”
    warming and the process is accelerating. The accelerating is accelerating
    and will have a significant affect on humans. Food, water and energy are
    the 3 main factors that everyone needs to focus on. Time to turn off
    Reality TV and prepare. Don’t rely on Monsanto to feed you. If we stop all
    Co2 now, the Earth will still keep warming until the balance can be
    repaired. No one knows how long that will be and how many of us will be

  • jay762360 1 year ago

    Carbon, as in ‘carbon pollution’, is co2, which we all breath out and the
    earth’s plantlife depend upon. There is a ‘greenhouse gas’ that is much
    more effective for causing climate change. That gas is water vapor. SO WE
    MUST ABOLISH CLOUDS OR WE WILL ALL DIE! Mankind has done 1/100000000
    towards co2 emmisions. The climate change thing is a monstrous scam by the
    world controlling banking elites who control entire nations with their
    monetary policies. Get informed please.

  • grindupBaker 1 year ago

    At 2:58 his 40,000 lbs CO2 per bod per year is incorrect, it’s 10,000 lbs
    CO2 per bod per year in 2013. His other science looks good though, just I’m
    better at sums, and his head-nodding etiquette for American politicians
    (with finger feature) is notable in the video “Nutty brainiac scientist
    meets Mr. Potato Head”. I suppose he might be a (gag gag) American in which
    case he’ll never have been told that there’s “persons” in the jungles
    across the sea, hence the 40k# each.

  • plank ton 1 year ago

    I need more supporting discussion re methane clathrate “safety valves”
    which Dr. Alley believes will probably prevent sudden [within 1-10 years]
    releases or “methane belches”….see at 10-14 minutes.

  • 4TIMESAYEAR 1 year ago

    Question: what does he mean by “climate change”?
    He makes it sound like we’re responsible for 100% of the CO2. We’re not. We
    are responsible for only 4% of the total amount of CO2. Only 4% – got
    that? He also makes it sound like it keeps building up – but it doesn’t –
    there is a CO2 cycle just like there is a water cycle. Lies, lies, lies.
    “Possible dragons” = theoretical nonsense. The planet isn’t going to do
    anything that it hasn’t done before. By the way, maybe he could do
    something about Etna and Sinabung before trying to do something about the

  • Edu hoeven, van der 1 year ago
  • citizenschallengeYT 1 year ago

    The facts are that atmospheric CO2 is increasing because of human’s refusal
    to slow it down – We Have Become A Huge Geophysical Force !
    that means we are warming our planet…
    that means our climate system is energizing…
    that means weather patterns are transitioning to a regime that will be very
    detrimental to our complex society and the human’s that depend on it.

    If you are looking for more facts:

  • thesiscokid1 1 year ago

    By far, one of the best slideshows I’ve seen.

  • James Skarnikat 1 year ago

    Cut the childish analogies and get to the facts, please.

  • Edward Greisch 1 year ago


  • ClimateState 1 year ago