This chapter explores the relationship between international trade and sustainable development, with a particular focus on climate change. It traces the evolution of the multilateral trading system from its origins in the General Agreement on Tariffs and Trade to the present day, highlighting the shift from a focus on trade liberalisation to a broader commitment to sustainable development. The chapter examines how the World Trade Organization has grappled with integrating environmental concerns into its framework, including the development of ‘greening’ jurisprudence, institutions, and rules. It proposes a reform agenda to further align the trading system with global sustainability goals, emphasising the need for alignment with climate change commitments, harmonised sustainability standards, reformed subsidy approaches, governance and institutional reforms, and a focus on equity and justice.