At the beginning of the summer, I noted how the climate-change narrative had changed in recent years, thanks to tremendous technological progress that has made green energy more competitive and often less costly than older carbon-based technologies. This is certainly true for new power investments, although for a while it will still be cheaper to produce electricity from older assets with sunk costs than to build new green plants. But in the medium term, I argued, “the new win-win story” implies that “national gains and commercial profit can now drive progress” toward a green transformation.

The climate debate is thus no longer only about the costs of mitigation and how to share them in an equitable and politically feasible way. Instead, as Nicholas Stern has said in his report to the G7, “the transition to a zero-emissions and climate-resilient world provides the greatest economic, business, and commercial opportunity of our time.”