Criminal activities that affect the environment and natural resources are on the increase and pose an increasingly serious threat to development. Data and analyses reviewed by the World Bank’s Community of Practice on ENRLE begin to show the magnitude of illegal logging, poaching of wildlife, trade in endangered species, wildland arson, criminal toxic releases, and other environment and natural resource–related crimes. They also show the diversity of the criminal threat, ranging from small-scale, artisanal crime that arises from poverty and inequities to growing problems of organized transnational criminal networks and enterprises using corruption, money laundering, technology, and other sophisticated methods to exploit persistent weaknesses in resource management and law enforcement. All World Bank client countries suffer from these crimes and are underserved by existing international law enforcement institutions and available mechanisms for support, capacity building, and operational cooperation. Vulnerability to environment crimes is often deepened by overarching problems of governance, corruption, and weaknesses in accountability at the national level.