International Investment Law and Environmental Protection offers the first truly comprehensive exploration of how investment treaties, arbitral practice, domestic regulation, and cross-cutting international legal regimes address environmental protection. Bringing together leading experts, the volume examines investor obligations, counterclaims, treaty design, climate-related regulation, and the evolving role of domestic and international law in shaping arbitral outcomes. This book equips practitioners, academics, policymakers, and students with the analytical tools needed to navigate one of the most pressing legal challenges of our time: the balancing of foreign investment against the protection of environmental commons in an era of climate urgency, technological change, and shifting global regulatory landscapes.