Perpetual Innovation

Category: Antarctica

  • Study Confirms World’s Coastal Cities Unsavable If We Don’t Slash Carbon Pollution | ThinkProgress

    Study Confirms World’s Coastal Cities Unsavable If We Don’t Slash Carbon Pollution | ThinkProgress:

    This article discusses the melt-off of Antarctica as discussed in a new Nature article. They did a better and more detailed analysis of the volume of water that would move into oceans as the Antarctic melts. They resolved a few of the issues that were not fully addressed by other studies. In addition to the models of ice volume/dynamics, they compared current warming with other times in history, thus offering benchmarks for validating their analysis.

    Even as many areas of Antarctica have been collapsing at an alarming rate, there has also been evidence of the snow building in the center of the (island? of Antarctica). This Nature study seems to resolve these apparent inconsistencies. They build a strong argument that we need to do a LOT now, not later. Many coastal cities will partially or totally under water if we continue for several more decades under the old business-as-usual model of carbon emissions.

    DeConto and Pollard (2016) in their article Contribution of Antarctica to Past and Future Sea-Level Rise look at ice dynamics to better analyze the volume of ice that should be displaced into the ocean waters as temperatures rise. They ran models under business-as-usual and more aggressive action scenarios. Then, they paired their results with key times in history where temperatures where high and sea-levels rose.

    They concluded that a likely scenario if we delay action is 1 meter (3.28 ft.)  of sea-level rise by end of century and 15 meters (~50 ft) by 2500 that would be attributable to antarctic ice melt. Add thermal expansion and other factors and this represents an ugly, ugly prospect.

    Reference

    DeConto, R. M., & Pollard, D. (2016). Contribution of Antarctica to past and future sea-level rise. Nature, 531(7596), 591–597. doi:10.1038/nature17145

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  • WMO Warns Lima Delegates 2014 May Be Hottest Year | Climate Central

    WMO Warns Lima Delegates, 2014 … Hottest Year in History!:-( | Climate Central:

    Ouch, this is really really ugly, the data related to 2014 as the hottest year in modern history.

    Double to the angst is the melt-off of the Antarctic.

    Here’s a discussion about both.

    The period between April and September, according to NASA GISS was the hottest in 120 years. Most (?all?) of the months since April will set all time heat highs, as well.

    Fortunately an El Nino weather pattern did not develop this year or the year-end temperatures would be even higher.

    The consistent march of the oceans to higher temperature is doubly scary. It should take years, if not decades for rising temperatures to make a dent in the ocean temperatures. If the oceans are, on average 2 miles deep, it should take a long time for warming at the surface to permeate down to the depths.

    Thermal expansion is scary. A 1 degree increase in surface temperatures, on average, should eventually result in about 2 feet of rise at the ocean surface due to thermal expansion as water gets warmer. This may take many years, but the increase is “baked in” if surface temperatures stay the same (or continue rising).

    But doubly worrisome are the ice sheets in Antarctica (and Greenland and Iceland) which are ice sheets on top of land. The Arctic in the north is generally ice on top of water, so when the ice melts up there, as it is rapidly doing, it does not affect ocean levels (directly).

    A study accepted for publication in the journal Geophysical Research Letters found that the Amundsen Sea Embayment in West Antarctica is melting quickly and at an increasing rate. They found that the ice loss was equivalent to the volume of Mt Everest every 2 years.


    The accepted draft of the article is here: paper…

    Too bad. After seeing some encouraging studies that suggested that there might be a bit of a hiatus to the march of global warming, some of the more recent measures are not so good.

    Ouch!:-(

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  • Scientists Warn of Rising Oceans From Polar Melt – NYTimes.com: … Implications

    Scientists Warn of Rising Oceans From Polar Melt – NYTimes.com:

    Or: http://nyti.ms/1sEIHC3 

    Studies published in the journals Science (here) and Geophysical Research Letters  (here) magazine find that the antarctic is melting, probably at a very very fast pace. The terms “beyond the point of no return” and “unstoppable” are used to describe the collapse of this glacial area in Antarctica. How long it will take is harder to predict.

    This really scares the bejeebers  out of everyone. Let me summarize a few reasons why this is bothersome:
    * It seems that arctic (north) should be shrinking a little and the antarctic (south) should be expanding if there were no human factors influencing such. So the shrinking/melt-off in the south would/should have to overcome this tilting effect of the earth, and then some. (This “effect” is something for people far smarter than I to explain.)
    * The north pole is now becoming more navigable, longer in the summer as the ice sheets melt off. China, for example is planning to navigate through a north passage for 3 months a year and avoid bringing oil from Russia through the Suez Canal, essentially cutting the trip in half (and maybe making twice 6-months worth of oil runs.
    * The melt off in the north pole is not as worrisome in terms of direct ocean level rise because much of the ice is over water, so the conversion from ice in the north pole to water is not a big deal related to ocean rise (although the resulting warming of the oceans from more heat absorption and less glacial reflection definitely is).
    * The antarctic is mostly over land. The melting of the Antarctic glaciers results directly into a rise in the sea levels.
    * Combine that with apparent acceleration effect, as the glaciers melt, they move faster and faster, accelerating the depletion process.
    * Thermal expansion. As ocean and land become exposed by the melting ice sheets, the ocean, land and air all become warmer. In the case of the oceans, water expands. If the average dept of the oceans are 2 miles, the oceans levels should rise at about 2 feet for every increase in (water) temperature of 1 degree Centigrade.

    At this rate, the best case by the IPCC of 2 degrees C increase in global warming has got to be very unlikely. The worst case scenarios of business as usual (BAU) of 3 to 4 degrees or more seem to be the most likely… The 4 degree increase would result in about 9 feet (or 3 yards) increase in sea levels.

    That means that by the end of the century, water-front cities will have new waterfront. Venus and New York will be new shapes and sizes. The Florida Keys will be less than half their current size.

    Some of us would argue that Business as Usual is not working so well, especially if you care much about your grand kids and great grand kids.

    Keywords: Antarctica, Arctic, business as usual, glaciers, Global Warming, IPCC, North Pole, sea levels, thermal expansion,

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