Hard to cut down on auto emissions when commuters travel longer distances in California

California has laid out a series of ambitious goals to cut down on car exhaust, but according to a new state report, auto carbon emissions — and the miles cars are being driven here — have been increasing steadily.

The reasons for the upsurge in pollution appear to be threefold: more people, more cars and — thanks to the housing crisis — more miles being driven by commuters between home and work and elsewhere.

“We were expecting single-occupancy car use to decline, but actually it’s going up,” said Nicole Dolney, co-author of a recently released California Air Resources Board report.