An Even Brighter Side of Global Warming?
| Richard Langlois |
I remain agnostic about whether global warming is taking place and, if so, whether it is being caused by human behavior. In part, my skepticism comes from some familiarity with large mathematical models in my graduate student days — and my recollection of how sensitive they are to the assumptions fed in. I certainly agree with Peter about what the issues are.
But I recently saw a review by Bob Whaples on EH.net (the economic history website and list-serve) of a book called Plows, Plagues and Petroleum: How Humans Took Control of Climate by William F. Ruddiman. According to the review, the earth for the last 900,000 years or so has experienced cycles in which massive glaciation lasting on the order of 100,000 years has alternated with comparatively brief (10,000 year) “interglacials.” Basically, the earth is now permanently colder than it was in the time of the dinosaurs, probably because there is now less volcanic CO2 and because the push of the Indian subcontinent into the Himalayas is somehow scrubbing CO2 from the atmosphere. Ruddiman apparently argues that the interglacial in which we now live is lasting longer than it should because humans have had an effect of warming the climate since the beginning of settled agriculture, which reduced forest cover in favor of crops. (Apparently the author also tries to link recent “little ice ages” to the plague and other events that took land out of cultivation, though, like Whaples, I find this less compelling.) Bottom line, as you might guess, is that we are long overdue for the next ice age, and what is saving us is — man-made global warming. Ruddiman apparently believes that global warming will be less than predicted and that before long the Ice Age will win. If the two trends ended up canceling each other out, it would probably be fitting, since global warming alarmism arguably had its roots in Ice Age alarmism. In any case, I have long hoped to see, as a throw-away bit in some science-fiction story, a depiction of giant furnaces in the Amazon valiantly trying to churn out CO2 to stave off a coming glaciation.