Robert Bryce, who has made a career out of saying things that are popular with the petroleum industry, is a lying liar who lies, most recently in the pages of The New York Times. In a recent op-ed he claimed, basically, that natural gas is greener than renewables because he says so.

Meanwhile, inventor and academic Dan Kammen is the chief technical specialist for renewable energy and energy efficiency at the World Bank, and he says Bryce is bad at math and also sort of making stuff up. Bryce purports to calculate just how challenging it would be for the U.S. to get itself off of energy sources that require us to destroy large swaths of land just to get them out of the ground. But according to Kammen, he’s calculating with numbers that make no sense.

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Skipping over the nit-picky details of this debate, here's the bottom line for the U.S. of A.:

Meeting a 33 percent renewable electricity mandate nationwide would require on the order of 800 square miles (2,072 square kilometers) of total area–much of which could be on the tops of buildings or in the case of wind, integrated into existing farmland (as is already the case in many wind farms). This is less than twice the size of Edwards Air force base, and less than one third of the area of forest estimated by the U.S. Environmental Protection Agency (EPA) to have already been destroyed by mountaintop removal coal mining.

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Bryce, meanwhile, overestimates the materials costs of reaching this goal by 400 percent, according to Kammen. He also manages to compare everything required to build a renewable power economy to just one tiny part of the natural gas infrastructure he favors — namely the turbine itself. It's a bit like comparing the entire manufacturing process of every component of an electric vehicle to the materials required to build just the engine of a conventional car, and then complaining that EVs are too hard to make.