Sen. Arlen Specter (D-PA) exits the polling booth after casting his ballot and answers some questions from the media during his U.S. Senate democratic primary re-election run in Philadelphia, Pennsylvania, May 18, 2010. REUTERS/Bradley Bower (United States - Tags: POLITICS ELECTIONS)
Greenpeace activists demonstrate before the Petersberg Climate Dialogue climate conference on May 2 near Bonn, western Germany. The US climate negotiator said Tuesday it was politically unrealistic for the next treaty to impose global targets on emission cuts, amid deep divisions among rich and developing nations. (AFP/DDP/File/Clemens Bilan)