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Gerbil wormingGerbil wormingPosted Jul 27, 2006 19:28 UTC (Thu) by ncm (subscriber, #165)In reply to: Ubuntu Linux 6.06 review (Jem Report) by drag Parent article: Ubuntu Linux 6.06 review (Jem Report)
Planetary temperature fluctuations aren't a crippling problem if they take thousands of years to manifest, but what we see happening now is way, way too fast for most species, including our own, to adapt to. Biologists estimate a loss of 30% of species by 2050. Mass extinctions have happened many times in the past. They also are not a crippling problem, except to the species that go extinct, or to the species that depend on them. Of course we do depend on a great many species, e.g. to eat, to pollinate crops, and to build houses from. Even in the worst case, humanity probably won't go extinct, but a 90% (or 99%) population reduction would be hard, particularly on those most dependent on the rest; e.g. you and me.
It's nice to pretend the Earth is too big for people to affect, but the facts are that (1) the CO2 level is much higher than a century ago, and (2) we are clearly the source, and (3) big changes obviously affect the climate.
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Global warming Posted Jul 27, 2006 21:35 UTC (Thu) by AJWM (guest, #15888) [Link] (1) the CO2 level is much higher than a century agoI'll give you that one, for very limited values of "much". (2) we are clearly the source But not that one. "Clearly"? I don't think so. Natural sources of atmospheric CO2 still outweigh anthropogenic sources. It could even be that global warming causes an increase in atmospheric CO2 -- warm water dissolves less gas than cold water, etc. (3) big changes obviously affect the climate Nor that one. Big changes in what, CO2? For what values of "big"? 10%, 100%, 1000%? How "obviously"? The greenhouse gas with the most effect on Earth's climate -- and there is an effect or else the polar caps would extend to about latitude 45 or so (recall how cold the Apollo 13 crew got when they had to power down and rely on the equilibrium between sunlight and thermal radiation) -- is H2O. Other gases like CO2 and CH4, etc. have relatively small contributions to the greenhouse effect. There is a lot of H2O in the atmosphere -- and 70% or so of the Earth's surface is open water. And are you sure it's not the climate (as influenced by, say, variations in the solar "constant") that has an effect on CO2 levels? Even assuming that global warming is actually happening -- it may well be, but the evidence isn't yet solid enough to rule out local warming -- there's no evidence that changing our CO2 production will have any effect on it. We may well be better off just painting our roofs and roads white, increasing (slightly) the planetary albedo and reflecting back more sunlight. Might be cheaper, too.
Global warming Posted Jul 28, 2006 8:43 UTC (Fri) by Wol (guest, #4433) [Link] I'll give you that one, for very limited values of "much". How's about a value of "much" of 100%? When I was at school, the percentage of CO2 in the atmosphere was accepted as 0.03%. Today's figure is 0.04%. Pre Industrial revolution it was 0.02%. So, in the period occupied by the industrial revolution (okay, that's two centuries, not one) the CO2 levels have doubled. That's amazing! The El Nino/La Nina cycle has driven or been driven by the South American Upwelling (not sure about cause and effect) for - according to geological evidence - maybe 150 million years. Global warming halted the upwelling in 1976. For the past 40 years, most of "the ten hottest summers to date" have all been in the preceding decade. In other words, pretty much EVERY summer for forty years has either been a record breaker, or not far off it. In other words, SOMETHING is up. Believe in global warming or not, as you wish. The evidence to me is frightening. And the consequences could be horrendous. How would you like to see sea-levels rise by metres over a period of days? That's quite plausible. What's going to happen when the Siberian Tundra melts? (They think that's gone past the point of no return already ...) Etc etc - we're in for an interesting century or two - I just hope it's not squashed into a decade or two instead ... Cheers,
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