vanBuskirk
Caldari
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Posted - 2007.12.03 15:09:00 -
[1]
The argument he put forward has even more force than he thinks, because his "worst case scenario" is not the worst case scenario. <WARNING CHAOS THEORY JARGON>
Climate modelling on a rather crude scale has been done - a rather better effort is being mounted by the power of the internet (www.climateprediction.com) but what appears to be the case is that with the continents as they now are there are three attractors, two more stable than the other one.
Case one is Snowball Earth. Ice everywhere, the entire ocean frozen over to a depth of hundreds of feet, no land life and only a little life hanging on next to undersea water vents. This is stable on a timescale of millions of years because almost all sunlight is reflected, but not stable on a longer scale than that - because CO2 emitted from volcanoes eventually builds up enough to flip it over to conditions hotter than today. Incidentally, this case is thought to have happened at least twice in Earth's history. And this case could happen as a result of the current warming trend - there is such a thing as overcorrection in control systems.
Case two is conditions more or less like today (at least on this scale) with possible fluctuations from the depths of an ice age to those like the Carboniferous Era - maybe ten degrees hotter than today. Either of these "extremes" is unpleasant, but humanity would most likely survive.
Case three is a hotter and nastier version of Venus. Hot enough at the surface for rocks to glow cherry-red and to melt lead, maybe a hundred atmospheres of surface pressure, clouds of concentrated sulfuric acid. This condition is permanent short of major astro-engineering projects.
If there is even the tiniest chance of case 1, to say nothing of case 3, then just about any cost can be borne in preference. Case 1 means humanity extinct. Case 3 means all life on Earth extinct - permanently. And nobody actually knows whether is possible. Possibly, the only way to find out is to do the experiment. I'd rather not.
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"Violence is the last refuge of the incompetent."
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