Building a Climate Coalition: Aligning Carbon Pricing, Trade, and Development

Global Climate Policy Project Working Group on Climate Coalitions

September 2025

This report from the Global Climate Policy Project at Harvard and MIT (GCPP) finds that a voluntary coalition of countries coordinating carbon prices could slash global emissions and raise billions for mitigation and adaptation, while avoiding a patchwork of unilateral border carbon measures.

The report, written in partnership with global experts, outlines a pathway to decarbonize heavy industry independent of UNFCCC timelines and centered on developing-economy priorities.

COP30-host Brazil has placed the proposal on its agenda for the Belém summit in November and is convening allied countries for technical sessions ahead of and during the global climate conference.

Many countries have begun introducing carbon pricing for heavy industry, laying the foundation to harmonize approaches and ratchet up ambition. Building on this momentum, this GCPP report includes modeling to quantify emissions, revenue, and trade effects under multiple coalition designs (different carbon prices, border measures). It also spells out an incentive package for low- and middle-income countries that would not undermine domestic production or spark trade conflicts.

Suggested Citation:

Global Climate Policy Project Working Group on Climate Coalitions. Building a Climate Coalition: Aligning Carbon Pricing, Trade, and Development. Cambridge, MA: Global Climate Policy Project at Harvard and MIT, 2025. https://ceepr.mit.edu/wp-content/uploads/2025/09/Full-Report-Building-a-Climate-Coalition.pdf