ON OCTOBER 19TH the International Energy Agency reported that doubling world GDP by 2040 would require only a small rise in energy demand if everyone adopted strict standards, like Japan’s for vehicle-fuel efficiency. That, the forecaster says, would be great news for consumers and the climate alike. Higher efficiency means less fossil fuel must be burned—and less planet-cooking gas belched—to power the global economy. But some economists are not so sure.
As nations grow wealthier, they have used more energy. Whether some of the extra joules consumed can be attributed to a more efficient use of energy has been debated since 1865, when William Stanley Jevons, a British economist, postulated that better steam engines would raise Britain’s overall demand for coal, rather than lower it. A new paper by Sebastian Rausch and Hagen Schwerin, of the Swiss Federal Institute of Technology, argues that something similar has…
