Associated Press: A day before he was to welcome hundreds of high-ranking officials for a summit on greenhouse gas emissions, Gov. Arnold Schwarzenegger raised the environmental stakes in California. Schwarzenegger signed an executive order committing the U.S. state to obtaining a third of its electricity from renewable sources by 2020. California previously had committed to producing 20% of its power from renewables such as wind and solar by 2010. “I am proposing we set the most aggressive …