USA's climate change
We go deep into the mighty Hoover Dam to explore the challenges of the United States' changing climate. In a cavernous hall inside the dam, giant turbines generate power for hundreds of thousands of American homes. In one of the US's driest regions, the Hoover Dam is part of a network of reservoirs which traps the waters of the Colorado river.
Justin Rowlatt talks to:
Dr Terry Fulp, regional director of lower Colorado region of the Bureau of Reclamation, who is responsible for the water supply to millions of Americans.
(Image: The low waterline by the Hoover Dam Credit: Getty Images)
Pat Mulroy, the head of the South Nevada Water Authority which serves Las Vegas.
And Professor Henry Jacoby, who works on the science and policy of Global Climate Change at the Massachusetts Institute of Technology.