GREENR (Global Reference on the Environment, Energy, and Natural Resources) This link opens in a new windowThe Global Reference on the Environment, Energy, and Natural Resources focuses on the physical, social, and economic aspects of environmental issues. Topic, organization, and country portals form research centers around issues covering energy systems, health care, agriculture, climate change, population, and economic development. Portals include authoritative analysis, academic journals, news, case studies, legislation, conference proceedings, primary source documents, statistics, and multimedia.