Developing countries are calling on the rich world to defy the US president, Donald Trump, and bridge the global chasm over climate action, before the goal of limiting global temperatures to safe levels is irretrievably lost. Diplomats from the developing world are rallying to support Brazil, which will host a crucial climate summit in November, after last year’s talks in Azerbaijan ended in disappointment and acrimony. Ali Mohamed, the chair of the African group of negotiators and Kenya’s special envoy for climate change, pointed to record temperatures last year and continuing extreme weather. “Africa, responsible for less than 4% of...