U.S. Secretary of Energy Steven Chu has warned that California's farms and vineyards could vanish by the end of the century if Americans do not act to slow the advance of global warming.

In a worst case, up to 90 percent of the Sierra snowpack in California could disappear, all but eliminating a natural storage system for water vital to agriculture, Chu said in an interview with the Los Angeles Times published on Wednesday.

With agriculture wiped out, California's major cities could be in jeopardy, Chu said.

"In his first interview since taking office last month, the Nobel-prize-winning physicist offered some of the starkest comments yet on how seriously President Barack Obama's cabinet views the threat of climate change, along with a detailed assessment of the administration's plans to combat it," the paper said.

In the interview, Chu warned of water shortages plaguing the West and Upper Midwest and particularly dire consequences for California, his home state and also the nation's leading agricultural producer.

"I don't think the American public has gripped in its gut what could happen," he said. "We're looking at a scenario where there's no more agriculture in California."

"I don't actually see how they can keep their cities going," he added.

Chu made clear that he sees public education as a key part of the administration's strategy to fight global warming -- along with billions of dollars for alternative energy research and infrastructure, a national standard for electricity from renewable sources and cap-and-trade legislation to limit greenhouse gas emissions.

The threat of warming is keeping policymakers focused on alternatives to fossil fuel, even though gasoline prices have fallen over the last six months from historic highs, he said.

Calling for more public awareness, he compared the situation to a family buying an old house and being told by an inspector that it must pay a hefty sum to rewire it or risk an electrical fire that could burn everything down.

"I'm hoping that the American people will wake up" and pay the cost of rewiring, said Chu.

(Xinhua News Agency February 5, 2009)