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unixronin: Galen the technomage, from Babylon 5: Crusade (Default)
Unixronin

December 2012

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Thursday, March 9th, 2006 08:30 pm

Pointed out by Peter Murray and [livejournal.com profile] dmmaus, respectively:

Tom Engelhardt of TomDispatch.com published this article which, among other things, covers Mike Davis's discussion of climatic tipping points, which in turn comments on such events as Hurricane Catarina -- the first South Atlantic tropical hurricane in meteorological recorded history -- and the accelerating decline in Arctic sea ice that has already made the long-fabled Northwest Passage all but a reality.  He raises the disturbing possibility that we might be on course for a runaway warming event far worse than postulated under the current mainstream position:

Where other researchers model the late 21st-century climate that our children will live with upon the precedents of the Altithermal (the hottest phase of the current Holocene period, 8000 years ago) or the Eemian (the previous, even warmer interglacial episode, 120,000 years ago), growing numbers of geophysicists toy with the possibilities of runaway warming returning the earth to the torrid chaos of the Paleocene-Eocene Thermal Maximum (PETM: 55 million years ago) when the extreme and rapid heating of the oceans led to massive extinctions.

...

[...] the August 23rd issue of EOS, the newsletter of the American Geophysical Union ... [included] an article entitled "Arctic System on Trajectory to New, Seasonally Ice-Free State," co-authored by 21 scientists from almost as many universities and research institutes ... [who made] a new observation -- that this process is probably irreversible.  "Surprisingly, it is difficult to identify a single feedback mechanism within the Arctic that has the potency or speed to alter the system's present course."

An ice-free Arctic Ocean has not existed for at least one million years and the authors warn that the Earth is inexorably headed toward a "super-interglacial" state "outside the envelope of glacial-interglacial fluctuations that prevailed during recent Earth history."  They emphasize that within a century global warming will probably exceed the Eemian temperature maximum and thus obviate all the models that have made this their essential scenario.  They also suggest that the total or partial collapse of the Greenland Ice Sheet is a real possibility -- an event that would definitely throw a Younger Dryas wrench into the Gulf Stream.

For some altogether colder water, NASA's Cassino mission has discovered strong evidence of liquid water on Saturn's moon Enceladus:

High-resolution Cassini images show icy jets and towering plumes ejecting large quantities of particles at high speed.  Scientists examined several models to explain the process.  They ruled out the idea that the particles are produced by or blown off the moon's surface by vapor created when warm water ice converts to a gas.  Instead, scientists have found evidence for a much more exciting possibility -- the jets might be erupting from near-surface pockets of liquid water above 0 degrees Celsius (32 degrees Fahrenheit), like cold versions of the Old Faithful geyser in Yellowstone.

The new finding offers an explanation for large amounts of free oxygen detected by Cassini in the vicinity of Saturn.

Thursday, March 9th, 2006 06:34 pm (UTC)
Natural processes don't work like that. They buffer themselves. When a stream gets too much crap in it, it marshes in and forms a natural filter. When air gets hot, it expands, which tends to cool it. Every action has an equal and opposite reaction, even Mr. Newton knew that hundreds of years ago.

Now, the natural cycle may be a lot *bigger* than stodgy old city planners are willing to deal with (see also, New Orleans).... but that doesn't mean the planet is going to be a bubbling stewpot in the forseeable future. Maybe temperate like the era of dinosaurs, yes.

The implication here is also that we puny humans could do anything big enough to actually influence that cycle. Do the math. Ice takes 30 cal/g to melt. Integrate over the Greenland ice sheet... and tell me how many gigatons worth of kaboom that represents.

Six bits says the end of the article says "needs more study, gimme more money"....
Thursday, March 9th, 2006 07:05 pm (UTC)
Bad ass. It's too cold anyway.

-Ogre