Why Americans have tuned out global-warming hype, and why they are right to do so.

Polls show that global warming has fallen to the bottom of the list of Americans’ worries. Meanwhile, 170 Michigan professors signed a letter (PDF) calling for tough climate legislation. I read the professors’ letter, and I have to say I’m with the people on this one.

The professors’ letter would be more convincing if they weren’t so dismissive of the costs involved. They cite unnamed “recent studies” that claim emission cuts could create 150,000 jobs in Michigan. I put more stock in the analysis (PDF) by the Energy Information Administration (EIA) of the 2007 Lieberman-Warner bill (which is similar to the Waxman-Markey bill that has passed the House of Representatives).

The EIA pointed out that cutting carbon dioxide emissions requires driving up energy prices, and this will shrink the economy. U.S. manufacturing would decline by 3% to 7%, depending on how successful the U.S. is at developing alternative energy sources, and manufacturing employment will fall between 3% and 10%. Of course, the professors won’t lose their jobs, but they should still be concerned about these things.

It is true that if you could convince taxpayers in the other 49 states to subsidize new, money-losing green energy projects in Michigan, then you might gain some jobs in Michigan. But when every other state is hoping to pull the same trick on you, it’s a zero-sum game. Actually, it’s worse: Subsidies for green jobs end up reducing national employment, not increasing it.

Unconvincing Scientific Argument

I also found the letter’s scientific content unconvincing. Regional climate forecasting is very conjectural, and models often contradict each other. I suppose it is possible that all four trout species could disappear as a result of a few degrees of warming over 100 years, but if trout were that delicate, the annual arrival of summer would have wiped them out long ago.

As for the litany of potential damages from recent warming trends, I browsed some of the longest histories for Michigan weather stations, such as Grand Rapids and Cheboygan. There are some trends, but after 1920 they are pretty small, especially considering the known warming bias in long-term climate data from regions undergoing urbanization.

The professors claim that these small trends could, among other things, destroy Michigan agriculture. Let’s give farmers a bit more credit. If farmers could not adapt to weather variability, agriculture in Michigan would have disappeared by the 1930s.

Even if the long list of problems could be blamed on CO2 emissions, the professors failed to mention that the small cuts envisioned under the proposed regulations would not change anything. The differences would be minuscule at the global scale, which is where they matter.

Ross McKitrick is a professor of economics at the University of Guelph, in Ontario, Canada, where he focuses on environmental economics. He was one of the debunkers of the “hockey-stick” analysis of global warming that argued that warming was increasing exponentially. His analysis, and that of others, has been validated and the “hockey-stick” analysis abandoned by the United Nations’ Intergovernmental Panel on Climate Change and other international analyses.