California has long been at the forefront of developing and implementing robust Cars Programs aimed at significantly reducing emissions from mobile sources. Recognizing that mobile sources are the largest contributors to both criteria air pollutants and greenhouse gases (GHG) within the state, the California Air Resources Board (CARB) has taken a leading role in combating air pollution. These mobile sources account for approximately 80% of ozone precursor emissions and around 50% of statewide GHG emissions, factoring in transportation fuel production and delivery. The severity of air pollution in California is underscored by the National Ambient Air Quality Standards (NAAQS). Ozone and fine particulate matter (PM2.5) are two pollutants of particular concern, and California faces significant challenges in meeting federal standards.
The state’s air quality is among the poorest in the nation. Notably, the South Coast and San Joaquin Valley air basins hold the unfortunate distinction of being the only regions in the United States classified as ‘Extreme’ nonattainment areas for the federal ozone standard of 70 parts per billion (ppb). These regions also experience alarmingly high levels of PM2.5 pollution, highlighting the urgent need for effective cars programs and emission reduction strategies. The Advanced Clean Cars II regulations are a vital component of California’s comprehensive approach to address these critical public health issues, in accordance with both state and federal legal requirements.
Emissions originating from motor vehicle engines have far-reaching detrimental effects on public health, the environment, welfare, and the global climate. These impacts are interconnected and multifaceted. Therefore, reducing one type of emission often contributes to the reduction of others, amplifying the overall positive impact. For instance, the increasing global temperatures exacerbate ozone pollution and increase the risk of particulate matter release from wildfires. By implementing effective cars programs that reduce emissions responsible for climate change, we can also enhance the effectiveness of efforts to control ozone pollution. The pollutants primarily responsible for ozone formation are oxides of nitrogen (NOx) and hydrocarbons (HC), both byproducts of fuel combustion in vehicles. These emission reductions are crucial for climate stabilization and for mitigating the risks of severe droughts and wildfires, which in turn contribute to fine particulate matter pollution. Well-designed cars programs are therefore essential for a healthier environment and a sustainable future.
