In a day of live journalism, California’s governor assailed President Trump, and the U.S. energy secretary called for countries to quit the Paris Agreement on global warming.

On Wednesday in New York, countries lined up to say they would accelerate their efforts to cut greenhouse-gas emissions. In staying away, the U.S. was all but alone.

President Xi Jinping told a U.N. climate summit that China will reduce emissions across its economy, expand renewables sixfold and make electric cars “mainstream.”