Wednesday 11 July 2007

40 years ago, people were worried about a new ice age. Not because its time had come, which it has for some time already. No, because the evil capitalist industry was filling the atmosphere with dust that would block the sunshine and cause Hell Earth to freeze over. Now, of course, the evil capitalist industry is filling the atmosphere with carbon dioxide which will make the planet too hot. And too wet and too dry and too cold, depending on what would be worst at any given place. Here in Norway, for instance, the idea is that the Gulf Stream may change its course or stop entirely, so we would be covered in glaciers again, or at least having to shovel snow on midsummer's night instead of dancing. In Sahara it will be drier (never mind that Sahara was green last time we had those temperatures, at the transition from Stone Age to early Bronze Age) and wherever there is too wet, there will be flooding. In short, Global Warming is indistinguishable from the Wrath of God. It is out to get us and is somehow targeting us with malice aforethought because we have abandoned the ways of our ancestors.

In light of the hyperbole, it is no wonder that many conservatives write off the whole man-made climate change as just another leftist scam to try to bring down capitalist society and introduce a Stalinist dictatorship in its stead. But reality is not quite that simple. The greenhouse effect is a scientific fact on the same scale as the world being more than 6000 years old. More, in fact, since you should be able to demonstrate the greenhouse effect in a good high school lab. Carbon dioxide and especially methane - both easily available - demonstrably absorb certain wavelength of light and heat better than others, which is why it lets sunshine through in the day but slows down heat radiating from the ground in the night.

The question then is not whether greenhouse gases have an effect, but whether this effect is good or bad. If we are on the verge of an ice age, staving it off with global warming seems like the decent thing to do. If the globe is thawing up anyway, it may be just as well if we save our fossil fuels for a later era where we may need them more. Not to mention that too much warming will cause almost all major cities to be flooded, since we have been in the habit of building cities on the coast since the onset of the Iron Age if not before. (The very oldest known cities were not port cities, actually. But I better not write more about that or I'll close this window and fire up Civilization again. Mmm, Civilization!)

In the current political climate, there is the more or less unspoken agreement that you should not make global warming seem like a possibly good thing: This would support the eevil dictator Bush and his War on Terra. Such an attitude is not entirely due to leftist toad demons possessing the scientists: It is in part because the Bush administration has done a great job in alienating scientists of various stripes, by trying to control both what research is done and how much of it is made public, and by leaning on voters who consider science a dark art and take for granted that God made the world roughly 6000 years ago.

If the political climate had been different, it would have been possible to draw very different conclusions from the same date. Notice how the article mentions that the earlier interglacials (time between ice ages, such as now) were around 50 000 years, then this Termination V was 28000 years, and the later were even much shorter, some of them as little as 10 000 years. It certainly looks like the ice ages are getting longer and the warm periods in between are getting shorter. In fact, there is an article in Scientific American March 2005 that indicates that humans may have caused global warming well before the modern age, through deforestation (carbon dioxide) and rice paddies (methane). When plotting these man-made contributions into the climate models, the author finds that parts of Canada would already have been covered by the next polar glacier without human intervention.

Be that as it may, I think the greenhouse gases we have already pumped into the atmosphere suffice for the next several generations, even if they were needed to stave off a new ice age. This is not about letting your car idle so I don't have to shovel snow up here in Norway. Rather, I have taken up the practice of not taking science at face value. Scientists, like the rest of us, are easily influenced by the Zeitgeist, the spirit of the times. And these days the spirit of the times is such that even many American Republicans don't want to mention Bush out loud. This is bound to influence people's attitude. So I subtract a little in my head whenever one of "his" topics comes up, just as I did when he was popular and I was an idiot for thinking that Saddam Hussein didn't have a stockpile of biological weapons. Or just like I do now that I am an idiot for thinking the American economy is a whitewashed grave just waiting to collapse. But that's not for today.