MOUNTAIN VIEW, Calif. -

Gov. Jerry Brown is set to continue his climate change charge, joining scientists releasing a 20-page call to action on environmental problems including pollution, extinctions and population growth.
    
Brown plans to address Silicon Valley leaders, as well as climate scientists from University of California, Berkeley, Stanford University and NASA, on Thursday morning at a conference at NASA Ames Research Center.
    
The governor has repeatedly called for changes in public policy to better address the impacts of the changing climate on the world's economy and environment.
    
Berkeley professor Anthony Barnosky, a featured speaker, says the earth is now at a tipping point, and what decisions makers do now "will determine whether or not human quality of life declines over the next few decades."