Cleaner Cars

Slowing down climate change means cars and trucks that pollute less, and some drivers have already put their money into eco-friendly vehicles. But how clean is that clean car? Millions of Volkswagen diesel owners were surprised and infuriated to learn in 2015 that their engines only passed U.S. pollution tests by cheating. That’s far from the only thing that can go wrong. Regulators and automakers are all making big, and often conflicting, bets on which technologies and incentives will get us to a low-emissions future faster. Some wild cards include cheaper oil and rising demand for cars in developing nations.

The climate change accord reached in Paris in December is expected to increase pressure for cleaner cars and trucks, which produce about a sixth of global carbon emissions and a quarter of the U.S. total. The pact came as the European Union was rethinking the tax incentives that helped diesel claim a market share of over 50 percent there. In the U.S., a federal standard calls for new cars to average 54.5 miles per gallon by 2025. Much tougher goals have been adopted by California, which accounts for one of every nine new U.S. vehicle sales and whose rules are followed by 10 other states. Both California and Japan are encouraging development of fuel cell cars, which create electricity by converting hydrogen to water, by building infrastructure for a network of fueling stations. Toyota and Honda are making big bets on fuel cells, along with Hyundai. To encourage fuel cell purchases, California is offering rebates of $5,000 per vehicle, twice what it offers for battery-powered electric vehicles. In Norway, heavily subsidized electric vehicles account for nearly a quarter of new car sales. In the U.S., sales of plug-in electric vehicles fell 17 percent in 2015 as gas prices tumbled; they now account for less than 1 percent of all sales.