California Air Resources Board

What you need to know: The California Air Resources Board has identified its research priorities for the next five years, which will inform science-driven policymaking at a time the federal government is rejecting accepted research on climate and air quality. 

SACRAMENTO, CA – The California Air Resources Board (CARB) has adopted its Five-Year Strategic Research Plan for 2025–2030, reaffirming the agency’s commitment to science-driven policymaking that protects public health and addresses the growing threats of climate change.  

The plan outlines CARB’s research priorities in five areas – health, ambient air quality, climate, mobile sources, and sustainable transportation, housing, and communities. Environmental justice and economic concerns are addressed throughout the five areas.  

“While the federal government recklessly dismantles decades of proven science and undermines public trust, California is doubling down on facts, data and accountability,” said CARB Chair Liane Randolph. “This plan isn’t just a roadmap for cleaner air and smart climate action, it’s a declaration that science still matters. We’re building policies that are resilient, adaptive and rooted in evidence.” 

CARB is continuing to embrace science-driven policymaking when the federal government is retreating from it. “Many of the California-specific research needs may be relevant to other jurisdictions, particularly where federal research may no longer be available,” the plan states. 

The plan incorporates public input from meetings, surveys, and a 30-day comment period. It will direct up to 12 research projects a year, often conducted by outside entities, with priority given to researchers at California State University and the University of California systems as required under state law.  

Five Research Areas 

1. Health 
CARB will expand research on the health impacts of air pollution and climate change, with a focus on vulnerable populations and cumulative effects. Priorities include wildfire smoke and extreme weather. 

2. Ambient Air Quality 
To meet increasingly stringent federal air quality standards, CARB will continue to study fine particulate matter (PM2.5), ozone, and air toxics. Research will support State Implementation Plans, improve air quality models, and address disparities in overburdened communities. 

3. Climate 
CARB’s climate research will support the state’s carbon neutrality goals by improving greenhouse gas (GHG) inventories, quantifying carbon sequestration efforts, and assessing the impacts of wildfires and refrigerants. The plan also emphasizes the co-benefits of climate action for all affected communities. 

4. Mobile Sources 
With mobile sources remaining the largest contributor to smog-forming emissions and GHGs, CARB will focus on real-world emissions monitoring, zero-emission vehicle adoption, and non-exhaust emissions like brake and tire wear. 

5. Sustainable Transportation, Housing, and Communities 
CARB will study strategies to reduce vehicle miles traveled, promote affordable infill housing, and support walkable, transit-accessible communities. Research will evaluate the effectiveness of land use, housing, and transportation policies in achieving climate goals and equity co-benefits. 

Research Successes 

The plan highlights examples of research that support policymaking: 

• Use of asthma medication was found to be significantly higher in overburdened communities because of exposure to emissions from ports and rail operations in Southern California. The research informs policies to reduce such emissions. 

• PM2.5 levels were found to vary a lot during the day in the San Joaquin Valley, knowledge which is helping CARB refine its policies for regulating emissions. 

• An aftertreatment system for engines was found to significantly reduce emissions, helping to inform state and federal emission regulations. 

Standing Up for Science 

The research plan is just the latest example of CARB standing up for science. Other examples include:  

• Earlier this week, CARB submitted a scathing critique opposing the U.S. Environmental Protection Agency’s (EPA) illegal push to end federal responsibility for greenhouse gas emissions by overturning its 2009 endangerment finding. 

• In August, CARB Executive Officer Dr. Steven Cliff testified against the proposal.  

• CARB provided a written rebuttal of the Department of Energy “study” that was used to end the endangerment finding, saying it was full of dangerous falsehoods. 

• CARB and other state agencies advanced a plan, built on public input, for clean vehicles and public health after federal agencies withdrew support for such efforts. 

• In March, CARB moved forward with a first-in-the-nation project that uses sensors on satellites to measure methane emissions.