* Correspondent, National Public Radio
* Washington D.C.
Sir Richard Jolly
* Chairman, Water, Sanitation, and Hygiene (WASH) Campaign, Water Supply and Sanitation Collaborative Council
* Geneva, Switzerland
* Director, Global Water Policy Project
* Visiting Senior Lecturer, Environmental Studies, Mount Holyoke College
* Amherst, Massachusetts
David K.C. Cooper
* Associate Professor, Surgery, Harvard Medical School
* Head, Xenotransplantation Group
* Transplantation Biology Research Center, Massachusetts General Hospital
* Cambridge, Massachusetts
This week presidents, prime ministers, delegates, and activists from some 190 nations are meeting in Johannesburg, South Africa for the UN World Summit on Sustainable Development. In this hour, we'll get an update from the conference, and take a closer look at one of its goals: increasing access to fresh water for the more than one billion people who lack a fresh water supply. Plus, the latest news on organ transplantation.