
Thu Dec 13, 7:53 AM ET
Former U.S. Vice President Al Gore waves to journalists as he arrives at the side event of the U.N. Climate Change Conference 2007 in Nusa Dua, on Bali island, December 13, 2007. The European Union threatened on Thursday to boycott U.S. talks among top greenhouse gas emitting nations, accusing Washington of blocking goals for fighting climate change at the U.N. talks in Bali.

Former Vice President Al Gore (L) and U.N. Secretary General Ban Ki-moon before their meeting on the side event of the U.N. Climate Change Conference 2007 in Nusa Dua, on Bali island, December 13, 2007. The European Union threatened on Thursday to boycott U.S. talks among top greenhouse gas emitting nations, accusing Washington of blocking goals for fighting climate change at the U.N. talks in Bali.

Nobel Peace Prize winner Al Gore, right, greets fellow Nobel winner Rajendra Pachauri, chief climate scientist for the UN's Intergovernmental Panel on Climate Change (IPCC) prior to addressing the UN Climate Conference Thursday Dec. 13, 2007 in Nusa Dua, Bali, Indonesia. Adding to pressure on the United States, Gore said in his address that the U.S. was 'principally responsible for obstructing progress here in Bali'.