Energy intersects with the environment at every stage of its life cycle. The energy supply chain can have adverse effects on nature and public health, including GHG emissions, air, land and water pollution as well the generation of harmful waste, among others. In order to reduce our dependence on high-carbon energy, more needs to be done to increase renewable energy generation and improve energy efficiency. As energy is involved in trade and investment projects, it is covered by the trade and investment branches of international economic law and regulated in these fields mainly by the rules of the World Trade Organization (WTO), the Energy Charter Treaty (ECT), regional trade agreements (RTAs) and international investment agreements (IIAs). This book aims to contribute to the existing scholarship by providing a comprehensive analysis of the energy–environment nexus under trade law and investment law, showing, where relevant, their similarities, differences or even (potential) conflicts at the energy–environment interface. It examines the legal foundations of the energy–environment nexus and associated issues regarding trade control, subsidies, technical standards, investment protection and technology policies.