Climate change and other global environmental problems require societies around the world to reform their institutions and decarbonize their energy systems. This global transition towards sustainability is often framed as a technical and economic challenge; but, social scientists increasingly draw attention to the political challenges this transition poses, including the distributive conflict sustainability reforms often trigger. This panel presents four papers exploring the political barriers to sustainability transitions. The research focuses on the relationship between policymaking institutions and environmental policy outcomes, emphasizing the ways institutions shape the capacity to undertake necessary policy reforms. In doing so, the papers address the political dimension of sustainability reforms at a variety of scales: from a focus on national and subnational policy processes, to the analysis of corporate actors and non-governmental organizations (NGOs). These papers also draw from a diverse range of methods, from qualitative case studies to careful econometric approaches. The first paper examines the implementation of renewable energy reforms in four US states (Arizona, California, Ohio and Texas). It seeks to explain the conditions under which policy design alters the subsequent politics of energy transitions, leading to expanded or contracted policies, and uses both qualitative and quantitative techniques. The second paper highlights the lack of adequate metrics to measure and track sustainability outcomes at an organizational level. This research identifies a framework for developing appropriate sustainability metrics to evaluate sustainability reporting both in the United States and internationally. The third paper examines the politics of domestic carbon pricing in four countries (the United States, Australia, Germany and Norway), examining how different patterns of business-state relations in social corporatist policymaking systems shapes variation in climate policy outcomes. The fourth paper evaluates the distributional implications of the Regional Greenhouse Gas Initiative (RGGI) on electrical utilities, providing a careful econometric analysis of how the policy has restructured electricity markets and their politics.