The scale, source, and allocation of climate finance have been contentious aspects of the Paris Agreement and its implementation. Central to these are questions of “fair shares”: who might contribute what and whether the group of contributors should be expanded. New analysis presented here concludes that there is a case for nontraditional donors providing 20-30 percent of any total, with this finding robust to a variety of different measures of historical emissions, cut-off dates, and income. China, Russia, South Korea, Saudi Arabia, Taiwan, Poland, the United Arab Emirates, and Mexico consistently feature in the top 20. Developed countries, however, should continue to take primary responsibility, with the United States shouldering at least 40 percent of the burden in virtually all scenarios. The politics of climate finance will continue to be difficult, but it is hard to escape the conclusion that both the United States and China will need to provide more.
The model that allows users to explore the effects of changing different measures and create their own scenarios is also published here.
Note: A CGD note, updating this work, as well as an updated spreadsheet model were published here on 31 May 2024.