Listen to "NBC Nightly News," providing reports and analysis of the day's most newsworthy national and international events. This audio podcast, updated each weekday evening by NBCNews.com, brings you the day's show in its entirety. For more from "Nightly News", visit http://www.nbcnews.com/nightly-news
Sen. Sheldon Whitehouse (D-RI) delivers a weekly speech on the Senate floor urging action on climate change. He speaks to Chief Environmental Correspondent Anne Thompson about his efforts.