Does combating climate change require burning the world’s forests and crops for fuel? It certainly looks that way, judging from the aggressive mandates governments across the globe have set to incorporate bioenergy into their transportation fuels in the hope of limiting the world’s overwhelming dependence on gasoline and diesel to move people and goods. While biofuels account for only about 2.5 percent today, the European Union expects renewable energy — mostly biofuels — to account for 10 percent of its transportation fuel by 2020. In the United States, the biofuel goal is about 12 percent by early in the next decade. The International Energy Agency envisions using biofuels to supply as much of 27 percent of the world’s transportation needs by midcentury. The reasons for such ambitions are clear: It is nearly impossible under current technology to run cars, trucks, ships and jet planes on energy generated […]