Reuters: The Obama Administration formally embraced the Copenhagen Accord on global warming on Thursday, a day after the president urged a fractious U.S. Congress to get to work on comprehensive legislation to stem the nation’s emissions. U.S. climate envoy Todd Stern gave notice to the United Nations that the country will aim for a 17 percent emissions cut in carbon dioxide and other gases blamed for global warming by 2020, from 2005 levels. The move, which confirmed the goal set by …