Associated Press: Negotiators for a new global warming treaty pressed Congress on Tuesday to approve legislation this year to reduce U.S. emissions of greenhouse gases. Todd Stern, the chief U.S. climate negotiator, was among those calling for a new law to be enacted before treaty talks begin in December in Copenhagen, Denmark. “The optimum would be legislation that is signed, sealed and delivered,” said Stern, who was appointed by Secretary of State Hillary Rodham Clinton as the U.S. envoy for …