Friday, April 25
Of Cheetahs And Men
A little background is needed for this one.
I was recently arguing in the comments at LGF with someone who claimed that the Theory of Evolution provided the basis for the Holocaust, much as Ben Stein does in Expelled.
He (the commenter, not Stein) provided a blatantly racist quote from T. H. Huxley in support of this claim. I countered that Huxley was morally and scientifically wrong; that such racism was endemic in the mid-19th century, even among abolitionists; and that the quote was taken from an essay Huxley wrote arguing for the abolition of slavery. And I provided a similarly racist quote from a abolition speech by Abraham Lincoln.
So said commenter asked me - rather condescendingly - what grand change had taken place in Evolutionary Theory since Huxley's day to make him scientifically wrong in this. And I pointed out that while race is a valid evolutionary concept, it doesn't apply to humans, because we lack sufficient genetic diversity. We're all one race.
The response asked, don't I think that this is miraculous? Clearly implying the hand of you-know-who.
And I said no; it just means we went through a genetic bottleneck in recent times, evolutionarily speaking. Much like cheetahs, which almost went extinct. But, I speculated, humans are more diverse than cheetahs, so we likely weren't as close to extinction as they.
But still too damn close for comfort. Just 70,000 years ago, our species may have been reduced to as few as 2000 individuals.
(via Slashdot)
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A little background is needed for this one.
I was recently arguing in the comments at LGF with someone who claimed that the Theory of Evolution provided the basis for the Holocaust, much as Ben Stein does in Expelled.
He (the commenter, not Stein) provided a blatantly racist quote from T. H. Huxley in support of this claim. I countered that Huxley was morally and scientifically wrong; that such racism was endemic in the mid-19th century, even among abolitionists; and that the quote was taken from an essay Huxley wrote arguing for the abolition of slavery. And I provided a similarly racist quote from a abolition speech by Abraham Lincoln.
So said commenter asked me - rather condescendingly - what grand change had taken place in Evolutionary Theory since Huxley's day to make him scientifically wrong in this. And I pointed out that while race is a valid evolutionary concept, it doesn't apply to humans, because we lack sufficient genetic diversity. We're all one race.
The response asked, don't I think that this is miraculous? Clearly implying the hand of you-know-who.
And I said no; it just means we went through a genetic bottleneck in recent times, evolutionarily speaking. Much like cheetahs, which almost went extinct. But, I speculated, humans are more diverse than cheetahs, so we likely weren't as close to extinction as they.
But still too damn close for comfort. Just 70,000 years ago, our species may have been reduced to as few as 2000 individuals.
(via Slashdot)
Posted by: Pixy Misa at
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1
In reading this brief description of a revolutionary way to track human lineage via population DNA mapping, I was struck by the theorized reduction of human numbers to the thousands. What is stated is the prolonged drought conditions in East Africa for several tens of thousands of years. I note that such conditions strongly imply a period of global warming. So, here's the right hand turn into bizarro contemporary political correctness and politics: how could this disaster be Bush's fault? And how could global warming occur in the absence of human-caused green-house gases? Kind of makes you look at pedants like Al Gore and think "Gosh, maybe planetary weather trends have extremes irrespective of human activity. Maybe the assumptions that current climate trends are caused by human activities, are just that, assumptions". Of course, that would be an inconvenient truth.
Posted by: Raging Duck at Friday, April 25 2008 06:03 PM (wyKPM)
2
Global warming and cooling periods have affected the Earth even in historical times. The Vikings settled Greenland, for example, during the Medieval Warm Period. Who today would voluntarily settle that place, much less name it "Greenland".
And then, during the Little Ice Age that followed, the Greenland colonies were wiped out.
The theory of Anthropogenic Global Warming is based on two factors: Global trends towards higher temperatures, and trends towards increased greenhouse gases in the atmosphere (primarily CO2, but also methane and others).
It's quite certain that if we pump enough CO2 into the atmosphere, temperatures will soar. It's the subject of mathematical modelling whether the amount of added CO2 at present is the cause of the temperature increases we've seen. The models are pretty convincing, but it's not an open-and-shut case.
It's still a good idea not to ignore the potential problem. Human industrial activity is large enough in scale to eliminate our biosphere by accident if we don't manage it properly. CFC's and the ozone layer were a pretty direct example of cause and effect, and in that case we acted promptly and the ozone layer recovered as predicted.
I'm no shrieking greenie, but I'm solidly in favour of constructing more nuclear reactors to replace coal-fired plants; the nuclear reactors are cleaner, produce negligible greenhouse gases, and release less radioactivity than coal.
And then, during the Little Ice Age that followed, the Greenland colonies were wiped out.
The theory of Anthropogenic Global Warming is based on two factors: Global trends towards higher temperatures, and trends towards increased greenhouse gases in the atmosphere (primarily CO2, but also methane and others).
It's quite certain that if we pump enough CO2 into the atmosphere, temperatures will soar. It's the subject of mathematical modelling whether the amount of added CO2 at present is the cause of the temperature increases we've seen. The models are pretty convincing, but it's not an open-and-shut case.
It's still a good idea not to ignore the potential problem. Human industrial activity is large enough in scale to eliminate our biosphere by accident if we don't manage it properly. CFC's and the ozone layer were a pretty direct example of cause and effect, and in that case we acted promptly and the ozone layer recovered as predicted.
I'm no shrieking greenie, but I'm solidly in favour of constructing more nuclear reactors to replace coal-fired plants; the nuclear reactors are cleaner, produce negligible greenhouse gases, and release less radioactivity than coal.
Posted by: Pixy Misa at Friday, April 25 2008 07:56 PM (PiXy!)
3
"Gosh, maybe planetary weather trends have extremes irrespective of
human activity. Maybe the assumptions that current climate trends are
caused by human activities, are just that, assumptions"
Giant meteors falling out of the sky and wiping out 90% of life on Earth are also purely natural phenomena, irrespective of human activity. And you know what? I don't want that to happen either.
If building a fleet of nuclear armed-spacecraft is what it takes to stop the next perfectly natural meteor, then I'm fine with paying for that. If reducing carbon emissions is what it takes to stop or mitigate the next perfectly natural global warming, then I'm fine with paying for that. Heck, I'm even fine with removing carbon from the atmosphere in an attempt to control the planet's natural cycles for our benefit.
What, exactly, do conservatives find disagreeable about this? When did the conservative movement buy into the liberal "naturalist" fallacy? Why is "it's natural" considered an answer to "the climate is changing" by the very same people who would be outraged if "it's natural" were the answer to the question "I'm bleeding and I'm going to die if you don't do something?"
Giant meteors falling out of the sky and wiping out 90% of life on Earth are also purely natural phenomena, irrespective of human activity. And you know what? I don't want that to happen either.
If building a fleet of nuclear armed-spacecraft is what it takes to stop the next perfectly natural meteor, then I'm fine with paying for that. If reducing carbon emissions is what it takes to stop or mitigate the next perfectly natural global warming, then I'm fine with paying for that. Heck, I'm even fine with removing carbon from the atmosphere in an attempt to control the planet's natural cycles for our benefit.
What, exactly, do conservatives find disagreeable about this? When did the conservative movement buy into the liberal "naturalist" fallacy? Why is "it's natural" considered an answer to "the climate is changing" by the very same people who would be outraged if "it's natural" were the answer to the question "I'm bleeding and I'm going to die if you don't do something?"
Posted by: Yahzi at Monday, April 28 2008 04:03 AM (yn9dj)
4
If reducing carbon emissions is what it takes to stop or mitigate the next perfectly natural global warming, then I'm fine with paying for that.What, exactly, do conservatives find disagreeable about this?
There's no evidence yet that reducing carbon emissions would have any effect at all on global warming. I'm against useless gestures which would be profoundly harmful in other ways.
Posted by: Steven Den Beste at Monday, April 28 2008 07:09 AM (+rSRq)
5
While it is true that CO2 is a greenhouse gas, the most important greenhouse gas on Earth is H2O. As vapor, water tends to trap heat. As clouds, water tends to reject heat. Both effects are stronger than the influence of the tiny amount of CO2 in the atmosphere. Also, CO2 is a trailing indicator of temperature change. As the temperature of the oceans rises, the solubility of dissolved gases including CO2 drops. The CO2 comes out of solution and goes into the air.
It is estimated that, if humans were to cease producing CO2 altogether (don't breathe!), the effect on climate temperatures would be too small to measure.
Finally, there are advantages to both warming and increased CO2. More CO2 makes plants grow better and need less irrigation.
Posted by: Dave at Wednesday, April 30 2008 02:58 PM (CkIMy)
6
As you say, CO2 is normally a trailing indicator, and in current events may well also be partially a trailing indicator. But we are dumping unusual (not unprecedented, but unusual) amounts of CO2 into the atmosphere, and it is a greenhouse gas, so caution is indicated.
You're right also that warming and CO2 both have benefits as well as costs. (Actually, I'm not sure there are any direct costs of increased CO2, at least at moderate levels.) But if climates change, say, it grows warmer, and the corn belt moves north (south in the southern hemisphere), the area with climatic conditions ideal for growing corn may coincide less with areas with soil suitable for growing corn, because the soils there were conditioned by millennia of a colder climate. And even if it works out even or better, transplanting agriculture from Kansas and Oklahoma to Manitoba and Saskatchewan is going to have its costs too.
So while I don't agree with the doomsayers, I do agree with those who advise caution. And nuclear reactors are shiny. Shiny is good.
You're right also that warming and CO2 both have benefits as well as costs. (Actually, I'm not sure there are any direct costs of increased CO2, at least at moderate levels.) But if climates change, say, it grows warmer, and the corn belt moves north (south in the southern hemisphere), the area with climatic conditions ideal for growing corn may coincide less with areas with soil suitable for growing corn, because the soils there were conditioned by millennia of a colder climate. And even if it works out even or better, transplanting agriculture from Kansas and Oklahoma to Manitoba and Saskatchewan is going to have its costs too.
So while I don't agree with the doomsayers, I do agree with those who advise caution. And nuclear reactors are shiny. Shiny is good.
Posted by: Pixy Misa at Wednesday, April 30 2008 05:18 PM (PiXy!)
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