Half a century after the civil rights era, struggles over air--what we breathe, the ways we know it, who governs it, and how to stake claims through it--have become central to science, politics, law, and the economy. This book explores the links among three urgent issues: rapid growth of urban inequality, amplification of political divisions in major democracies, and the increasing impact of pollution and global warming. It examines how communities on the margins of interconnected energy hubs navigate the social, cultural, and health consequences of air pollution, and how long-running battles over industrial toxicity are being reshaped as climate science becomes central to governance.