Thinking in Herds

William Happer is a professor of physics at Princeton University and one of a tribe that's come to be known as global warming skeptics. He gives us an explanation for his skepticism in an essay at First Things which I commend to everyone interested in the issue, whichever side of it one is on.

Happer examines the mix of scandals, politics, money and science that attach to the issue of global warming, and what he says, to the extent that it's accurate, is very helpful in understanding what's really going on amid all the confusing claims and counterclaims.

Here are a few paragraphs to serve as an appetizer:

Other things being equal, more CO2 will cause more warming. The question is how much warming, and whether the increased CO2 and the warming it causes will be good or bad for the planet.

The argument starts something like this. CO2 levels have increased from about 280 ppm to 390 ppm over the past 150 years or so, and the earth has warmed by about 0.8 degree Celsius during that time. Therefore the warming is due to CO2. But correlation is not causation. Roosters crow every morning at sunrise, but that does not mean the rooster caused the sun to rise. The sun will still rise on Monday if you decide to have the rooster for Sunday dinner.

Let me summarize how the key issues appear to me, a working scientist with a better background than most in the physics of climate. CO2 really is a greenhouse gas and other things being equal, adding the gas to the atmosphere by burning coal, oil, and natural gas will modestly increase the surface temperature of the earth. Other things being equal, doubling the CO2 concentration, from our current 390 ppm to 780 ppm will directly cause about 1 degree Celsius in warming. At the current rate of CO2 increase in the atmosphere—about 2 ppm per year—it would take about 195 years to achieve this doubling. The combination of a slightly warmer earth and more CO2 will greatly increase the production of food, wood, fiber, and other products by green plants, so the increase will be good for the planet, and will easily outweigh any negative effects. Supposed calamities like the accelerated rise of sea level, ocean acidification, more extreme climate, tropical diseases near the poles, and so on are greatly exaggerated.

It is worth recalling now a quotation from the preface of the second edition of Mackay’s Extraordinary Popular Delusions and the Madness of Crowds: “Men, it has been well said, think in herds; it will be seen that they go mad in herds, while they only recover their senses slowly, one by one.”

Between these graphs is a lot of very helpful information on how some of the climate change folks have suppressed dissenting views and manipulated data to get the results they want. It's not pretty, but it's important. It would be an historic blunder if fear of a calamity that's not really pending were to cause us to needlessly and severely diminish our standard of living by disdaining the use of fossil fuels.