Even as concerns over climate change and environment have become dominant in political discourse, our understanding of the coupled dynamics of human and natural resource systems remains limited. Using a combination of computational, theoretical and econometric tools, and data from 11 countries, I present new knowledge and insights into how poor communities respond to food aid, the mechanics of environmental policy and the relationship between environmental quality and ecosystem health on human health. By showing the environment and human outcomes as intimately connected, this dissertation provides economic motivation for environmental conservation.