#UnionOfConcernedScientists

Despite aggressive regulatory efforts to counter pollution, California emissions from on-road transportation rose by roughly 4.4 million metric tons of carbon dioxide in 2015 vs one year earlier, according to the San Francisco-based non-profit Next 10. The state also had the dubious honor of housing six of the country’s 10 most polluted cities, based on data from the American Lung Association’s annual “State of the Air” report released last April.

While topography plays a major role (cities located in valleys and basins have a tendency to trap air pollutants), much of the problem has to do with Californians driving more. Let’s face it, gas is cheap and public transit options are typically the less-enjoyable option in all but the most densely packed cities. In fact, the Los Angeles County Metropolitan Transportation has seen declining ridership over the last two years — even though the city has a major issue with traffic.