Climate Change: Union of Concerned Scientists' Knobloch talks about the state of climate research

Many scientists agree that greenhouse gas emissions from man-made sources are at least partially responsible for global climate change. But is the science really in about the best methods to mitigate carbon dioxide emissions? Could the climate be near a tipping point, where a slight temperature increase causes drastic changes? And can new climate research ever trump the politics that govern the global warming debate? During today's OnPoint, Kevin Knobloch, president of the Union of Concerned Scientists, answers these questions and more.