"An immediate and growing threat."
That's how California's lead environmental agency -- and the Governor's office -- describe climate change in the latest in a series of periodic reports on the subject.
The report cites "already discernible impacts of climate change" and attempts to pinpoint the main drivers -- no pun intended. In California, nearly 40 percent of greenhouse gas emissions come from the transportation sector -- trains, planes and automobiles, and the last in particular.
According to the report from the state Environmental Protection Agency, the annual average temperature in California has risen about 1.5 degrees (F) -- but the state isn't warming up uniformly. Parts of the Central Valley and Southern California are heating up faster; the hot are getting hotter. And a particularly insidious aspect of warming: overnight low temperatures are rising twice as fast as daytime highs. This has clear implications for agriculture, as many important cash crops, like stone fruits, need a certain amount of "chill time" to produce bountiful, quality fruit. Warmer nights put more pressure on the electric grid as air conditioners run longer, and also limit recovery time during hot spells, worsening the effects of heat waves.
And yes, those are increasing, the Cal/EPA report finds, and in some surprising places, such as the North Coast (bear in mind that what passes for a "heat wave" in Mendocino is a little different from the Mojave threshold).