Fair contributions versus fastest possible reductions. Equity considerations in the context of the Paris Agreement and the climate emergency

A major question of international climate policy is which countries have to reduce their greenhouse gas emissions by how much. As ambitious global climate policy has been delayed for long, emissions now have to be reduced in all countries as fast as possible. Considerations whether the national emission pathway itself is in line with the responsibility and capability of that country moves more and more into the background. It is now more a question of who pays for the transition, not where it is happening. In this paper with Fraunhofer ISI, we argue that only the combination of assessments on "what is a fair contribution" and of "how much could emissions technically be reduced" can give sufficient guidance for national greenhouse gas emissions targets that are in line with the Paris Agreement. If the national potential is not large enough to represent a fair contribution (likely for most developed countries), these countries should support other countries to make the transition. If the highest possible ambition leads to faster reductions than the fair contribution (likely for many developing countries), these countries would receive financial support.