The document discusses the economic perspective of environmental protection, emphasizing that environmental issues stem from economic activities and their externalities. It argues that effective solutions must be economically sensible and politically pragmatic, particularly in light of global climate change as a free-rider problem requiring international cooperation. The California cap-and-trade system serves as a case study for effective carbon pricing and policy integration, highlighting lessons on market-based approaches, the necessity of government involvement, and the importance of participation from developing countries.