"UNITED NATIONS — The United Nations Climate Action Summit on Monday was meant to highlight concrete promises by presidents, prime ministers and corporate executives to wean the global economy from fossil fuels to avoid the worst effects of global warming. But despite the protests in the streets, China on Monday made no new promises to take stronger climate action. The United States, having vowed to pull out of the Paris Agreement, the pact among nations to jointly fight climate change, said nothing at all. A host of countries made only incremental promises."