Environmental policies are often economic protectionism in green clothing. A case in point is California's low-carbon fuel standard, whose constitutionality is being challenged in federal court. It's also a case study of the incredible contortions of green policy-making today.

California's low-carbon fuel mandate requires the state, by 2020, to reduce the "carbon intensity" of its transportation fuels by 10%. Carbon intensity is a fuel's "life-cycle emissions," which include the energy needed to produce...