Most volumes in the environmental economics literature consider the environment to be a public good and hence write out a role for the private sector in a source of supply. Yet there is ample evidence of the private sector being involved, driven both by profit and altruism. This book provides the necessary conceptual base for the inclusion of the private sector in the environmental protection supply equation and deliver an extensive set of examples in a wide range of contexts. In an economic climate where governments are attempting to reduce expenditures, the increased role for the private sector will be readily embraced by policy makers.The aim of the book is to establish the principles of markets in the provision of environmental protection and to provide an extensive experience-based set of contexts in which the private sector has acted to enhance the supply of environmental goods and services. These contexts include both pure-private sector initiatives in terrestrial, aquatic and marine ecosystems and public-private sector ‘joint initiatives’ such as payment for environmental services (PES) schemes.