Mercury, a tenaciously persistent element, doesn't just go away. In towns along the Madre de Dios River in Peru, David Gonzalez is studying how gold mining puts public health at risk.
Amchi Nyima Samphel, a ninth-generation Tibetan healer, discusses traditional medicine and the challenges his practice faces in the 21st century.
David Gonzalez takes us just off the coast of Southern California, to an island chain heralded as the "Galapagos of North America."
Before UN delegates arrived in Warsaw for the latest round of climate negotiations, students from 8 universities gathered at Yale to come up with their own climate solutions.