California’s Plan to Decarbonize Trucks with Dr. Steve Cliff

Image: A commercial truck driving under an underpass. Communities living near areas with heavy trucking face disproportionately high levels of air pollutants. By Chris Yarzab –, CC BY 2.0,

Audio Editing by: Wangyuxuan Xu Blurb by: Alexandra Jade Garcia and Elizabeth Sherstinsky Script by: Marie Hogan

California Air Resources Board: Zero-Emission Trucking Goals

The California Air Resources Board (CARB) is the agency responsible for reducing California’s climate-changing emissions and accelerating the transition away from combustion powered vehicles. This includes promoting the manufacturing and sale of zero-emission trucks and other heavy-duty vehicles. CARB’s goals for zero-emission trucks in California include (1) 100% of new zero-emission vehicle sales by 2035, (2) a full transition to zero-emission vehicle drayage trucks by 2035, and (3) a full transition to zero-emission vehicle buses and heavy-duty long-haul trucks by 2045, where feasible. 

What is CARB Doing to Meet These Goals?

CARB is working to meet these goals through financial incentives, infrastructure development, regulations, collaboration with partners in government and industry, and information dissemination about zero-emissions trucking. Financial incentives include point-of-sale discounts on zero-emission trucks and buses, credits for lower-carbon-intensity fuels, incentives for building charging stations, loan assistance for buying zero-emission trucks, and more. 

Advanced Clean Trucks Regulation

In California, the transportation sector is responsible for about 50% of greenhouse gas emissions and a major source of air pollution. Trucks are a potent mobile source of emissions, contributing to about 70% of smog pollution and 80% of carcinogenic diesel pollution. CARB regulations aim to accelerate the zero-emissions truck market as an essential part of achieving California’s goals of reducing emissions to fight climate change and improve clean air standards. This includes the Advanced Clean Trucks Regulation, a manufacturers zero-emissions vehicle sales requirement and one time reporting requirement for large entities and fleets. The goal of the Advanced Clean Trucks Regulation is to accelerate the transition of medium and heavy duty zero-emission vehicles. 

Who is Steve Cliff?

Dr. Steve Cliff is the Executive Officer of the California Air and Resource Board (CARB). Cliff began his appointment in the Summer of 2022 and works with the board to enact programs to reduce air and climate pollution within the state. In his role, Cliff oversees over 1,800 employees and a budget of $2.7 billion. Before serving as Executive Officer Cliff worked as the 16th Administrator of the National Highway Traffic Safety Administration (NHTSA) and was appointed by President Biden in January 2021. 

Dr. Steve Cliff received his bachelor’s and a doctorate in chemistry from the University of California, San Diego. He also has a postdoc on atmospheric sciences from the University of California, Davis. For over two decades Cliff has worked closely with UC Davis, he worked as a research professor in the Department of Applied Sciences, has supported air quality and climate research programs, and is affiliated with the school’s Air Quality Research.


Dr. Steve Cliff: Trucks make up about 1.8 million of the 30 million vehicles on California’s roads today. But they account for, uh, about a third of  transportation related emissions.

Ethan: How can we reduce pollution and greenhouse gas emissions from trucks? I’m Ethan Elkind, and this is Climate Break. I spoke to Dr. Steve Cliff, executive officer of the California Air Resource Board, the agency in charge of meeting the state’s climate goals. He says the answer is zero emission trucks, powered by clean fuel like electric batteries.  They’re now going to be required under the agency’s new advanced clean trucks regulation. 

Dr. Steve Cliff: Advanced clean trucks requires an increasing proportion of sales by manufacturers of medium and heavy duty trucks to be zero emissions and ultimately that will help drive us to a hundred percent zero emissions fleet in the medium and heavy duty, uh, trucking.

Ethan Elkind: Cliff believes this type of rule will help eliminate truck pollution not just in California but throughout the world.

Dr.  Steve Cliff: You have a lot of benefits to a broader economy and more jobs. If you look at the light duty sector as an example for how this has blossomed – medium duty and heavy duty trucks, the same kind of thing exists. We’ve already developed the market for it. The products now exist. Many of the learnings exist. That’s enough to drive not only the increased number of vehicles in the market, but to drive down costs globally.

Ethan: To learn more about the California Air Resources Board’s policies supporting zero-emission trucking, visit

California’s Plan to Decarbonize Trucks with Dr. Steve Cliff