Californians pay about 15 cents a gallon extra at the pump to fight climate change. Here’s what they’re getting for their money: continued progress in the effort to curb carbon. Greenhouse gas emissions fell by 1.5 million tons in California in 2015, state officials announced Wednesday. The reduction was the equivalent of pulling 300,000 cars off the road for a year, according to the California Air Resources Board. The agency said emissions dropped 0.3 percent compared with 2014, and have fallen a total of 10 percent since 2004.