This chapter examines constitutional mechanisms for environmental governance in response to the intensifying climate emergency and environmental crises. It explores structural, procedural, and substantive constitutional reforms designed to improve accountability, democratic participation, and environmental decision-making. The discussion categorizes these mechanisms into structural design and procedural commitments—such as deliberative democratic institutions and rights-based approaches—and substantive commitments, including constitutional environmental rights and fixed legal obligations. While these mechanisms vary in form and effectiveness, they reflect an ongoing global effort to integrate environmental priorities into constitutional frameworks, shaping governance beyond traditional legislative politics.