How green are biofuels? Scientists are at loggerheads

Tyler Lark, a geographer at the University of Wisconsin-Madison, grew up among farms, working on a neighbor’s dairy, vaguely aware of the tension between clearing land to grow food and preserving nature. As an engineering student working on water projects in Haiti, he saw an extreme version of that conflict: forests cleared for firewood or to grow crops, producing soil erosion, environmental denudation and worsening poverty. “I think it was that experience that told me, ‘Hey, land use is important,’” he says.