Protagonists of global environmental governance often view the sovereign State as well as the principle of sovereignty as major stumbling blocks for effective environmental conservation and sustainable development. Some even herald the demise of the idea of the sovereign State. However, reality has it differently. Sovereignty is no longer an unqualified concept. Manifold new duties have been imposed upon the sovereign State as a result of the progressive development of international law. Much of the modern international law movement vests States with the responsibility to adopt regulations, to monitor and secure compliance and exercise justice in order to achieve its implementation, whereas supranational global environmental governance has remained notoriously weak. This article examines this proposition by reference to the environmental and developmental role of states in three landmark multilateral treaties: The United Nations Law of the Sea Convention (1982), the Convention on the Conservation of Biological Diversity (1992) and the Paris Agreement on climate change (2015). They demonstrate that sovereignty serves as a key organisational principle for the realization of global values, such as environmental conservation and sustainable development.