This book presents the major themes of the economic literature on natural resources and the environment. It is designed to bring the reader, in part with the aid of a unified model of optimal resource use, to the frontiers of the discipline, using only elementary mathematical models. Features special to exhaustible and renewable resources, including the problems posed by market imperfections, are treated as extensions of the basic model. The theoretical discussion is enriched with examples and applications, including a systematic investigation of the behaviour of resource reserves, costs, prices, and substitution possibilities. Substantial attention to environmental, as well as extractive, resources is a distinctive aspect of this book. The author describes methods of estimating the environmental costs of resource development and other projects, and presents some key empirical findings. Policy instruments to protect the environment, such as taxes, subsidies, marketable permits, and direct controls, are carefully analysed from a welfare-theoretic point of view.