The alliance of rich, emerging and poor economies that sealed the Paris climate deal is falling apart. In 2015, the world’s top two emitters, the US and China, joined with Brazil, some small island countries and the European Union, led by Germany, France and the UK, to land the agreement. But climate change politics have shifted significantly since then, with two more big tilts this week. Brazil elected a staunch and radical anti-environmentalist president, while Germany’s Angela Merkel confirmed her exit plans