The report of the Joint Task Force on Climate Action, Carbon Pricing, and Policy Spillovers, with participation by the IMF, OECD, UNCTAD, World Bank, and WTO, makes four main contributions. First, it reflects on a common understanding of carbon pricing metrics which inform on the incentives to decarbonize and on cross-country variation in carbon prices, a key determinant of international spillover effects and competitiveness concerns. Second, the report analyzes the appropriate mixes of climate change mitigation policies, emphasizing the pivotal role of carbon pricing as the only policy implementing the polluter pays principle while generating revenues. Third, it analyzes how international organizations can support the coordination of policies to maximize positive and limit negative cross-border spillovers from climate change mitigation policies. Finally, it discusses how such coordination can help to scale up climate action by closing the transparency gap, the implementation gap, and the ambition gap.