For three decades, the United Nations has been holding an annual summit on the climate known as COP, which stands for Conference of the Parties. Delegates travel to a chosen city from around the world to try to find ways to prevent or mitigate the worst effects of global warming.

Experience has shown that progress can hinge on a variety of factors, including which country is hosting. This year’s COP30 is taking place in Brazil, a nation that embodies the tensions and contradictions the world faces as governments try to decarbonize economies without slowing economic growth.