KATY TUR (HOST): The science, the science is there and you can't-- it's hard to argue with the science. When you look at the report that was put out by the U.N., the congressional report that was put out, the science says that if swift action is not taken and big actions are not taken quickly then we're not going to be in a good position in 50, 60, 70, 80, 90 years.