Future directions in human-environment research.

Human-environment research in the 21st century will need to change in major ways. It will need to integrate the natural and the social sciences; it will need to engage stakeholders and citizens in the design of research and in the delivery of science for the benefit of society; it will need to address ethical and democratic goals; and it will need to address a myriad of important theoretical and methodological challenges that continue to impede progress in the advance of sustainability science.