Morgan - perhaps you would like to share how you think trends in California have anything to do with global warming (much less whether those trends are caused by CO2 in the first place).

But since you think it's relevant.........here's the first paragraph of the story, which you quoted.

Originally Posted By: DA Morgan

Average temperatures in California rose almost one degree Celsius (nearly two degrees Fahrenheit) during the second half of the 20th century, with urban areas blazing the way to warmer conditions, according to a new study by scientists at NASA and California State University, Los Angeles.


Urban areas are blazing the way to warmer conditions eh? Perhaps you think that climate change affects urban areas more than rural areas? Give me a break.
Morgan - why don't you ask yourself what possibly could be going on in those urban areas that could make them hotter than the countryside?

Here's a hint........pavement and concrete.

What do you know - the researchers understand this linkage, perhaps you didn't read the full article (did you stop at the headline?). Here's a couple significant quotes.

"Average temperatures increased significantly in nearly 54 percent of the stations studied, with human-produced changes in land use seen as the most likely cause. The largest temperature increases were seen in the state's urban areas, led by Southern California and the San Francisco Bay area, particularly for minimum temperatures. "

"Patzert said the increased rate of minimum temperatures has led to narrower daily temperature ranges throughout the state. "California nights are heating up, giving us a jump start on hotter days," said Patzert. "This is primarily due to increased urbanization, not increases in cloudiness or precipitation."