The idea that cars could run on maize and peanut oil is hardly revolutionary. Henry Ford and Rudolf Diesel both designed engines powered by biofuels a century ago. Cheap supplies of crude oil rendered them uneconomic. On Tuesday the European Union will seek to turn back the clock. To combat climate change, it will set out steps to boost the use of biofuels. It is embarking on a flawed strategy.

Biofuels are touted as a cleaner transport fuel than oil. While burning ethanol and biodiesel emits carbon dioxide, the gas is absorbed by crops – including maize, sugarcane and rapeseed – that are grown to produce the fuels. The EU Commission, convinced of the benefits, wants biofuels to account for 10 per cent of road fuel consumption by 2020.