Book excerpt: This book examines cooperation on shared environmental concerns across national boundaries in the Southern Cone region of South America, specifically Argentina, Brazil, Paraguay and Uruguay. It covers regional environmental cooperation in the Southern Cone since the early 1990s. By using the marginalised issues of ecological and socio-environmental concerns as an analytical lens, the author makes a significant contribution to the study of regional cooperation in Latin America. Her book also presents the first detailed study of how environmental cooperation across national boundaries takes place in a region of the South, and thus fills a lacuna in global environmental governance. This innovative work is geared toward students and scholars of environmental politics, regional cooperation in Latin America, and transboundary environmental governance.