The twenty-first century presents an increasing number of environmental problems, including toxic pollution, global warming, destruction of tropical forests, extinction of biological diversity, and depletion of natural resources. These environmental problems are generally due to human behavior, namely over-consumption of resources and overpopulation. Designing effective policies to address these problems requires a deep understanding of human behavior as well as ecology. This in turn requires considerations of human nature, and the evolutionary "design" of the human mind.