World's Desert Cities 'May be Living on Borrowed Time': UN Report

"The 500 million people who live in the world's desert regions can expect to find life increasingly unbearable as already high temperatures soar and the available water is used up or turns salty, according to the United Nations. Desert cities in the US and Middle East, such as Phoenix and Riyadh, may be living on borrowed time as water tables drop and supplies become undrinkable, says a report coinciding with today's world environment day.

Twentieth-century modernist dreams of greening deserts by diverting rivers and mining underground water are wholly unrealistic, it warns.

But the report also proposes that deserts become the powerhouses of the next century, capturing the world's solar energy and potentially exporting electricity across continents."