Delegates at the climate summit at Copenhagen concluded two weeks of debate and negotiations Saturday,  deciding to "take note" of an agreement to reduce greenhouse gas emissions, but the outcome left some environmentalists disappointed. Other leaders said the accord, which commits to keeping the average global temperature rise below 2 degrees Celsius, is an important first step in finally stimulating action among developing nations, especially the United States.

Learn more about the behind-the-scenes drama at Copenhagen in these videos, ranging from registered delegates being literally left out in the cold to interviews with renowned climatologist Stephen Schneider, author Tom Friedman and Radiohead frontman Thom Yorke.