President Obama will propose a reduction in U.S. greenhouse-gas emissions “in the range of 17%” during a United Nations climate-change conference on Dec. 9, the White House announced on Nov. 25. The proposal that Obama will offer at the meeting, to be held in Copenhagen, would trim emissions in 2020 about 17% from 2005 levels. The climate-change bill that the House passed in June also calls for a 17% cut.