State Has Ambitious Climate Change and Air Quality Goals. California has a variety of goals related to reducing greenhouse gas (GHG) emissions, as well as regional and local air pollution. For example:
- GHG Limit. Chapter 249 of 2016 (SB 32, Pavley) established a statewide GHG limit of 40 percent below 1990 levels by 2030. (The Governor also has an executive order establishing a goal of statewide carbon neutrality by 2045, but this target is not in state law.)
- Federal Air Quality Standards. California has two areas with the most critical air quality challenges in the nation—the South Coast Air Basin and the San Joaquin Valley. Substantial reductions in criteria pollutants from all sources—specifically, nitrous oxides (NOx) and fine particulate matter (PM2.5)—are needed to meet increasingly stringent federal air quality standards in the coming years.
- AB 617 Community Emissions Reduction Plans. Pursuant to Chapter 136 of 2017 (AB 617, C. Garcia), some of the communities with the worst air quality in California have adopted plans that identify five‑ and ten‑year targets to reduce air pollution exposure from various sources.
Mobile Sources Represent a Large Portion of Emissions. Emissions that come from vehicles and other types of mobile equipment are also known as “mobile sources.” Mobile sources include several different types of vehicles and equipment, such as:
- Light‑Duty Vehicles. This includes passenger cars and smaller pick‑up trucks. Currently, most of these vehicles have gasoline‑powered internal combustion engines.
- Medium‑Duty Vehicles. This includes vehicles that weigh more than 8,500 pounds up to 14,000 pounds, such as larger pick‑up trucks and neighborhood delivery vans. Currently, these vehicles are primarily fueled by gasoline or diesel.
- Heavy‑Duty Vehicles. This includes large trucks (such as long‑haul trucks), garbage trucks, some port equipment (such as drayage trucks), and buses. Currently, most of these vehicles are powered by diesel engines, or in some cases the vehicles use hybrid technologies or engines powered by natural gas.
- Off‑Road Equipment. This includes a wide range of equipment types, including locomotives, ocean‑going vessels, commercial harbor craft, portable generators, agricultural equipment, construction equipment, lawn and garden equipment, forklifts, aircrafts, and recreational boats. Currently, most of this equipment is powered by diesel engines.
As shown in Figure 1, mobile sources represent a substantial share of California’s GHGs and air pollution. In particular, these sources represent about 40 percent of GHGs and over 70 percent of statewide NOx emissions. (This does not include “upstream” GHG emissions, such as emissions related to producing or refining crude oil.) Light‑duty vehicles make up the largest share of mobile source GHG emissions, while heavy‑duty vehicles and off‑road equipment make up the majority of mobile source NOx. Heavy‑duty vehicles and off‑road equipment are also primary sources of diesel particulate matter, which the California Air Resources Board (CARB) estimates is the source of 70 percent of total known cancer risk related to air toxics in California.
Air Pollution Differs Between Regions and Communities. Certain regions—such as the Central Valley and South Coast—and communities—such as those near ports, highways, and freight corridors—are disproportionately impacted by air pollution from mobile sources. In addition, as shown in …….