The politicians listen to the economists because the economists bring them funding and approval. GDP is the first cold sore we need to destroy. It should be replaced with a “Net” domestic product that takes a carbon budget into account (and also methane, which is 10–20x more powerful as a greenhouse gas).

By changing just this one measure of economic progress, having it take environments costs into account, countries will start caring about measuring their carbon budget just for the sake of economic competition.