Bloomberg: The U.S. rejected a Chinese proposal that developed countries should contribute a percentage of their gross domestic product to mitigate the effects of climate change. China, the world’s second-biggest emitter of carbon dioxide, called for developed nations to provide financial support of 0.5 percent of their GDP a year to help it and other developing nations fight global warming. Asked whether China’s proposal is reasonable, Harlan Watson, the U.S. climate-change negotiator, said: “No.” In …