California's strategy to fight climate change includes hydrogen. The universe's most abundant element that, under the right circumstances, can power everything from trucks to turbines without greenhouse gas emissions. Now there's a national effort to promote hydrogen energy. But there are concerns about health and safety. Guest: Molly Peterson, Public Health Watch In addition to destroying homes and property, the explosive Park Fire is also putting one of California’s most iconic species at risk. Reporter: Rachel Becker, CalMatters Learn more about your ad choices. Visit megaphone.fm/adchoices