Humanity's impact on the planet is undeniable. Fairly and effectively addressing environmental problems begins with understanding their causes and impacts. Is overpopulation the main driver of environmental degradation? Poverty? Capitalism? Poor governance? Imperialism? Patriarchy? Clearly these are not technical questions, but political ones. Updated to cover new debates, data, and policy, and expanded to include chapters on colonialism, race and gender, and the impacts of energy and resource extraction, this book introduces students to diverse perspectives and helps them develop an informed understanding of why environmental problems occur. How the international community should act is deeply contested. Guiding students through the potential responses, including multilateral diplomacy, transnational voluntary action, innovative financial mechanisms, problem displacement, consumer-focused campaigns, and resistance, this book explains the different forms of political action, their limitations and injustices. Online resources include lecture slides, a test bank for instructors and updated weblinks to videos and suggested readings for students.