With the sudden bang of a gavel Saturday night, representatives of 195 nations reached a landmark accord that will, for the first time, commit nearly every country to lowering planet-warming greenhouse gas emissions to help stave off the most drastic effects of climate change.<br />The deal, which was met with an eruption of cheers and ovations from thousands of delegates gathered from around the world, represents a historic breakthrough on an issue that has foiled decades of international efforts to address climate change.<br />President Obama, who regards tackling climate change as a central element of his legacy, spoke of the deal in a televised address from the White House.<br />"This agreement sends a powerful signal that the world is fully committed to a low-carbon future," he said.
