A member of the Ya̧nomamö people at Irotatheri community in Venezuela's Amazonas state, near the Brazilian border, in September 2012. Leo Ramirez/AFP/Getty Images hide caption

itoggle caption Leo Ramirez/AFP/Getty Images

July 2010: Two pelicans sit on booms protecting Queen Bess Island, La., from oil that spilled after the Deepwater Horizon rig exploded in April. Chris Graythen/Getty Images hide caption

itoggle caption Chris Graythen/Getty Images

Navy specialists repair a weather buoy collecting data for the National Oceanic and Atmospheric Administration (NOAA) off the Atlantic coast of Africa. President Richard Nixon, a Republican, created NOAA, one of our principal resources for understanding the Earth's climate. Elizabeth Merriam/U.S. Navy hide caption

itoggle caption Elizabeth Merriam/U.S. Navy