Greenpeace activists hang off of the West End Bridge, one of downtown Pittsburgh's iconic bridges, with a massive banner displaying a message to Group of 20 leaders gathering for the September 24 summit. The banner, nearly 80-feet by 30-feet in size, takes the form of a stylized road sign that warns of the political maneuvering and delay that have put a international climate treaty in jeopardy as the world enters the final stretch on the road to Copenhagen.