Sacramento Bee: An overwhelming majority of Californians believe the state should act to curtail greenhouse gas emissions, according to a new poll, while residents narrowly oppose hydraulic fracturing and support construction of the Keystone XL pipeline. Climate change represents a concrete threat for a majority of Californians, according to the new Public Policy Institute of California poll. More than three-fourths of respondents -- 77 percent -- called climate change a "very serious" or "somewhat serious" threat...