As a result, many environmentalists are dismissive of biofuels as a long-term solution, particularly because a growing world population will need more food. To limit global warming to a 1.5C increase in temperature would require so much biofuel that it would take up to 7m square kilometres of arable land — roughly the size of Australia — to produce that much feedstock, according to a recent report from the UN Intergovernmental Panel on Climate Change.
“If you were to replace all today’s aviation fuel with biofuel, with first-generation biofuel, it would be at the expense of 2,100 calories per person per day for everyone on the planet,” says Prof Berners-Lee. “It would take almost all of humankind’s calorific requirements . . . So that is absolutely not a solution.”