This two-volume set provides an authoritative overview of the major environmental issues of the 21st century, with a special focus on current challenges, trends, and policy choices. This set provides an up-to-date, comprehensive, and focused resource for understanding the nature and scope of environmental challenges facing the United States and the world in the 21st century, as well as options for meeting those challenges. Volume One covers environmental trends and challenges within the United States, while Volume Two illuminates environmental issues and choices around the world. Issues covered in both volumes include vital topics such as climate change, air and water pollution, natural resource and species protection, and agricultural/industrial impacts on the environment and public health. For all topics, the authors—scholars and experts hailing from a wide range of environmental and policy fields—detail a range of political, social, and economic options for the future and explain why the issue in question is important for society and people as well as the natural world.