Wow, you all thought I was shrill. Here's new Energy Secretary Steven Chu, in an interview with the Los Angeles Times on the dangers facing the United States if carbon emissions keep rising at their usual rate:

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

In a worst case, Chu said, up to 90% of the Sierra snowpack could disappear, all but eliminating a natural storage system for water vital to agriculture.

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

A pair of recent studies raise similar warnings. One, published in January in the journal Science, raised the specter of worldwide crop shortages as temperatures rise. Another, penned by UC Berkeley researchers last year, estimated California has about $2.5 trillion in real estate assets -- including agriculture -- endangered by warming.

Chu then went on to reiterate the Obama administration's plans to avoid that fate—public funds for alternative-energy research, a national renewable-electricity standard, a cap-and-trade for greenhouse gases... No eye-openers there. But then, as if silently nodding to that recent Pew poll finding climate change low on the public's list of policy priorities, Chu conceded that "public education" would have to be a big part of the administration's strategy.

--Bradford Plumer