Air Resources Board

California may be facing a period of volatility on both gas supply and price as it attempts to wean itself from combustion-powered transportation, its largest single source of greenhouse gas emissions.

Bikers — many of whom love their noisy combustion engines — say zero-emission motorcycles aren’t ready for long-distance rides. Motorcycles emit an “outsized portion” of smog-causing pollutants.

The state air board will vote on changes to its landmark clean fuel program that would cut more greenhouse gases but could raise the cost of gas and diesel.

The CalVans program in the Central Valley transports thousands of laborers to the fields. It is now trying to meet a mandate to electrify its fleet — a key test of how to make the state’s climate policies work in rural and disadvantaged areas.

California has amassed a catalog of programs and projects that fail to deliver as promised. The list of dysfunctional efforts has a couple of new entries.

China modeled some of its climate programs on policies first adopted by California. Now, California depends on the world’s most populous country for essential materials in its electric vehicle ambitions.

California grants climate credits for fuel made from cow manure, but there’s a paradox: The state's program encourages collection of methane yet promotes natural gas.

California wildfires every year emit as much carbon as almost 2 million cars, posing a threat to efforts to battle climate change.

Since 2011, 80% of the credits issued by a California program aiming to reduce pollution have gone to biogas and biofuel projects that have their own environmental drawbacks. Meanwhile, communities near oil refineries and dairies suffer the brunt of the impact from ongoing emissions.

The state Air Resources Board voted today to ban the substance known as chromium 6, giving platers several years to switch to an alternative the platers say won’t produce the same chrome shine.