The Environmental Sustainability Index (ESI) is a composite index tracking 21 elements of environmental sustainability covering natural resource endowments, past and present pollution levels, environmental management efforts, contributions to protection of the global commons, and a society's capacity to improve its environmental performance over time.
The Pilot, 2001, 2002 and 2005 ESI was compiled by Yale University Center for Environmental Law and Policy in collaboration with Columbia University's Center for International Earth Science Information Network (CIESIN), and the World Economic Forum.

2005 rankings