Problem: The United States uses a whole lot of energy.

Solution: Spend $420 billion building solar collectors across 19% of the American Southwest. Done.

Via MeFi.

Lake Mead, the water source for nearly 8 million people (including both Las Vegas and Los Angeles), could go dry by 2021.

The study’s findings indicated that there is a 10 percent chance that Lake Mead could be dry by 2014 and a 50 percent chance that reservoir levels will drop too low to allow hydroelectric power generation by 2017. There is a 50 percent chance the lake will go dry by 2021, the study says.

Researchers say that even if water agencies follow their current drought contingency plans, those measures might not be enough to counter natural forces, especially if the region enters a period of sustained drought or if human-induced climate changes occur as currently predicted.

"We were stunned at the magnitude of the problem and how fast it was coming at us," said study coauthor Tim Barnett of the Scripps Institution of Oceanography of the University of California at San Diego. "Make no mistake, this water problem is not a scientific abstraction, but rather one that will impact each and every one of us that live in the Southwest."

In the pictures left and up top, the white level on the rocks indicates where the water level used to be.

Here's another striking photo, courtesy of National Geographic:



At Lake Mead National Recreation Area, for instance, a barren landscape has replaced a harbor that once attracted campers and boaters.