This newly and fully revised fifth edition explores the two opposing paradigms of sustainability in an insightful and accessible way. Eric Neumayer contends that central to the debate on sustainable development is the question of whether natural capital can be substituted by other forms of capital. Proponents of weak sustainability maintain this is possible, whilst followers of strong sustainability regard natural capital as non-substitutable. Using global warming and other major environmental issues as examples, he shows how policies and solutions radically differ depending on which paradigm is more plausible. Neumayer examines the availability of natural resources for producing goods and services and the environmental consequences of economic growth. He identifies the critical forms of natural capital in need of preservation given uncertainty about the future and opportunity costs of preservation. This edition incorporates new developments such as safe operating spaces within planetary boundaries to deal with uncertainty and ignorance. The book also provides a critical assessment of sustainability measures. It analyses weak sustainability measures such as the Change in Total Wealth Per Capita and the Index of Sustainable Economic Welfare (also known as the Genuine Progress Indicator) as well as strong sustainability indicators including Ecological Footprints, Material Flows and the Strong Environmental Sustainability Index. This seminal book will prove essential reading for students, scholars and policymakers with an interest in ecological and environmental economics and sustainable development.