Perhaps Uma Thurman and Kevin Spacey can help answer that question. After all, the two actors co-hosted the performance, which itself is meant to draw attention to what the former vice president calls a “planetary emergency.” Speaking at a press conference today, Ms. Thurman, 37, said, “The whole point is to raise awareness and communicate with everyone else in the world and share our concern for the planet.” She went on, “What we are hearing is that everyone needs to get very much involved with climate. It's coming to us. It's coming to a theater near us, very, very near us.” And Mr. Spacey, the cagey actor who currently oversees artistic affairs at London’s Old Vic theater, brought up an eco-friendly project that his playhouse is working on, called “Go for Green.” According to the 48-year-old thespian, the effort will culminate in a play that means to better educate young audiences on problems facing the environment. “I think that showing up at an event like this is important because there are going to be so many young people tuning in to this concert,” he said.