SilverBoat -> RE: Settled Science (1/29/2012 9:49:06 AM)
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Well, I'm not a climate scientist, but I'm an engineer who didn't sleep at a Holiday Inn last night ... http://maps.grida.no/go/graphic/carbon_cycle I don't know if that schematic shows the latest and greatest figures, but it's close enough for discussion purposes. A few relevant points: - The Earth currently radiates more heat than it absorbs (it had a lot of kinetic energy from accumulating, and there's nuclear decay continuing). - In a few billion years, that will change, as the Sun enters its red-giant phase (okay, maybe not so relevant at the moment). - Its core temperature is about 4000-5000 *C, and mantle temperatures range from 500-900 *C. - The crust and atmosphere temperatures range from 400 to -200 *C (or so). - The background temperature of empty space is -270*C. So, basically, we're standing on a 7000-mile glob of molten metal, with its top 1500-miles sort of slushy, and we've got about 20 miles of slag under our feet, and about 20 miles of air and steam over our heads. For the last billion years or so, there's been some seesawing of water between solid, liquid and vapor forms. There's some plausible evidence that various life-forms sequestered enough (maybe 99%?) of the atmospheric carbon during the previous couple of 'hot' billion years to mostly do themselves in by chill or starvation, or at least relegate themselves to deepwater thermal vents, etc. We're at least third-generation life forms, parasites dependent on vegetation that depended on chemosynth or something from billions of years ago. I dunno where the tipping points are on that, but yanno, neither does anybody else. Dumping significant amounts of carbon etc back into the atmosphere doesn't seem circumspect, because it might be the equivalent of roofing over the layers of insulation with tinfoil; things will get hotter underneath. ...
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