Reflecting a global trend, scores of countries have affirmed that their citizens are entitled to healthy air, water and land, and that their constitution should guarantee certain environmental rights. This book examines the increasing recognition that the environment is a proper subject for protection in constitutional texts and for vindication by constitutional courts. This phenomenon, which the authors call environmental constitutionalism, represents the confluence of constitutional law, international law, human rights and environmental law. National apex and constitutional courts are exhibiting a growing interest in environmental rights, and as courts become more aware of what their peers are doing, this momentum is likely to increase. This book explains why such provisions came into being, how they are expressed, and the extent to which they have been, and might be, enforced judicially. It is a singular resource for evaluating the content of and hope for constitutional environmental rights.