"Negotiators at the United Nations climate summit scrambled Wednesday to bridge multibillion-dollar disagreements as President Barack Obama and other world leaders prepared to descend on the Danish capital Friday." ... "US Secretary of State of State Hillary Clinton Thursday proposed that major economies including the US come up with $100 billion a year over the next decade for developing nations, in an eleventh-hour effort to break an impasse." Secretary of State Hillary Clinton arrived in Copenhagen with new offers of conditional aid, but it was unclear whether this would be enough to break the logjam.