Associated Press: Industrial countries are falling short of pledging to slash their carbon emissions by 2020 on the scale needed to prevent climate disasters, U.N. climate chief Yvo de Boer said Wednesday. But the chief U.S. delegate urged negotiators from 175 countries to think of longer-term objectives rather than focus on short-range targets that would be difficult to meet. “We are actively working to move forward aggressively,” Jonathan Pershing told hundreds of delegates on the final day of …