Environmental scientist and tropical ecologist Gretchen Daily thinks about our environmental challenges, and the people affected by them, on many levels. At one level, there are everyday farmers, ranchers, fishermen, and other producers. “People who work on the land, some who work on the water,” she said. At another level, there are the huge, often impersonal entities—nation states, the European Union, the World Bank—that seek to structure those producers’ lives and, to at least some extent, the natural world in which we all live. “All of us are drawing from the same natural asset base, and we all need to somehow change the system together—it’s way beyond the power of any one producer, or even any one major industrial or financial player in the system,” Daily said. The size and urgency of our environmental problems led her to think in new ways about nature—and to encourage others to think in …