Transformative and accountable climate governance must address trade and investment law. As part of that agenda, there is a need to ensure that investor-state dispute settlement (ISDS) clauses in trade agreements are not used to delay, disrupt, and block action in respect of the governance of the environment, biodiversity, and the climate. This chapter has several parts. First, it examines the ISDS matter between the Lone Pine Resources Inc. and the Government of Canada over a fracking moratorium in Quebec under the North American Free Trade Agreement (NAFTA) 1994. Second, it focuses on the ISDS conflict between TransCanada and the Government of the United States under NAFTA over the decision of President Barack Obama to halt the Keystone XL Pipeline. Third, it considers public policy options in respect of the reform of the ISDS regime in the context of the re-negotiations over the NAFTA. Finally, it examines the implications of such investment disputes over environmental and climate matters for the Trans-Pacific Partnership 2015 (TPP). ISDS poses significant challenges to the global goals associated with sustainable development and international climate action. Experts call for the reformation of ISDS at the very least – if not its abolition.