Does Los Angeles Have the Greenest Carbon Footprint in the USA?

Just a month ago, the American Lung Association said that aggressive efforts have improved air quality in Los Angeles. Instead of being America’s worst polluter, it is second worst after Pittsburgh, Pennsylvania. But today the Brookings Institution, a well-regarded Washington think-tank, reports that Los Angeles is greener than Portland or San Francisco—in fact it’s carbon foot-print beats any city except Honolulu.