01 October 2009

If Sea Level Rise is Unstoppable . . .

If sea level rise is unstoppable, as argued by Stefan Rahmstorf in news article excerpt below (emphasis added), then what does that imply for justifying mitigation policies based on modulating, even stopping, sea level rise in the next century?
A rise of at least two meters in the world's sea levels is now almost unstoppable, experts told a climate conference at Oxford University on Tuesday.

"The crux of the sea level issue is that it starts very slowly but once it gets going it is practically unstoppable," said Stefan Rahmstorf, a scientist at Germany's Potsdam Institute and a widely recognized sea level expert.

"There is no way I can see to stop this rise, even if we have gone to zero emissions."

Rahmstorf said the best outcome was that after temperatures stabilized, sea levels would only rise at a steady rate "for centuries to come," and not accelerate.

Most scientists expect at least 2 degrees Celsius warming as a result of man-made greenhouse gas emissions, and probably more. The world warmed 0.7-0.8 degrees last century.

Rahmstorf estimated that if the world limited warming to 1.5 degrees then it would still see two meters sea level rise over centuries, which would see some island nations disappear.

His best guess was a one meter rise this century, assuming three degrees warming, and up to five meters over the next 300 years.

"There is nothing we can do to stop this unless we manage to cool the planet. That would require extracting the carbon dioxide from the atmosphere. There is no way of doing this on the sufficient scale known today," he said.

5 comments:

  1. "There is no way I can see to stop this rise, even if we have gone to zero emissions."

    Talk to some good engineers who are capable of thinking outside the box.

    There are several ways to stop or greatly reduce sea level rise from melting ice in Greenland and Antarctica. The following list is partial, and not in any particular order:

    1) Create "sea curtains" that keep warm ocean water from getting underneath the ice shelf in the Antarctic,

    2) Cover melting ice or snow, particularly in the summer.

    3) Generate a layer of fresh snow every winter, by using sea water or meltwater to create snow when the temperature is cold. This would raise the albedo of the ice caps.

    4) Create dams and pump the meltwater back up each winter, so that the meltwater refreezes.

    5) Fill moulins with material (e.g. inflatable bags, like an airbag) such that meltwater can not run to the base of the glacier, lubricating the glacier base so that the glacier moves faster.

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  2. Given how badly Rahmstorf butchered his most famous study, why would anyone listen to him?

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  3. Assuming that ocean level and temperature both rise gradually but more-or-less continuously throughout any given interglacial, it seems to me that, regardless of to what degree man has warmed the climate, this is a problem we would have had to face eventually (and have already faced in the past, if I'm not mistaken).

    It's disturbing to me that Dr. Rahmstorf seems to suggest in the last sentence that the ideal solution to this problem - where the difference between it being labeled a "natural" problem or "man-made" problem seems to me to be just a (possibly short) matter of time - is geoengineering rather than adaptation.

    I wonder if rising sea levels weren't seen by so many as a mostly man-made problem, how proposals of drastic geoengineering to mitigate it would be received.

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  4. "That would require extracting the carbon dioxide from the atmosphere."

    Mmmm... after doing that (if it's possible extract the carbon dioxide from atmosphere), Dr. Rahmstorf maybe want to kill all the plants and vegetation, because the plants produce carbon dioxide during the night. And put every human being in a bubble to stop our individual emmisions of CO2.

    Science... so much bizarre things be done in your name.

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  5. This is your typical kill the parents and plead for mercy as an orphan post? Yes?

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