ClimateWire: The United States has officially promised the world that it will reduce global warming pollution about 17 percent below 2005 levels in the next decade. Now the question is whether President Obama can deliver. In an announcement yesterday, U.S. climate envoy Todd Stern submitted America’s target to the U.N. Framework Convention on Climate Change as part of a Jan. 31 deadline negotiated in Copenhagen last year. In doing so, Stern made a point of noting that the final figure could change …