The California Air Resources Board is charged with implementing California's comprehensive suite of policies to reduce emissions of
greenhouse gases. In part due to CARB, California has successfully decoupled greenhouse gas emissions from economic growth, and achieved its goal of reducing emissions to 1990 levels four years earlier than the target date of 2020.
Alternative Fuel Vehicle Incentive Program Alternative Fuel Vehicle Incentive Program (also known as Fueling Alternatives) is funded by the California Air Resources Board (CARB), offered throughout the State of California and administered by the California Center for Sustainable Energy (CCSE).
Low-Emission Vehicle Program The CARB first adopted the Low-Emission Vehicle (LEV) Program standards in 1990 to address smog-forming pollutants, A second amendment, LEV III, was adopted in 2012, and covers vehicles sold from 2015 onward for both smog (superseding LEV II) and GHG (superseding Pavley) emissions. The rules created under the LEV Program have been codified as specific sections in Title 13 of the
California Code of Regulations; in general, LEV I is § 1960.1; LEV II is § 1961; Pavley is § 1961.1; LEV III is § 1961.2 (smog-forming pollutants) and 1961.3 (GHG). The ZEV regulations, which were initially part of LEV I, have been broken out separately into § 1962. For comparison, the average new car sold in 1965 would produce approximately of hydrocarbons over of driving; under the LEV I standards, the average new car sold in 1998 was projected to produce hydrocarbon emissions of over the same distance, and under LEV II, the average new car in 2010 would further reduce hydrocarbon emissions to .
Required labeling In 2005, the California State Assembly passed AB 1229, which required all new vehicles manufactured after January 1, 2009, to bear an Environmental Performance Label, which scored the emissions performance of the vehicle on two scales ranging between 1 (worst) and 10 (best): one for global warming (emissions of GHG such as , ,
air conditioning refrigerants, and ) and one for smog-forming compounds (non-methane organic gases (NMOG), , and ). The Federal Government followed suit and required a similar "smog score" on new vehicles sold starting in 2013; the standards were realigned for labels applied to 2018 model year vehicles.
Vehicle categories The LEV program has established several categories of reduced emissions vehicles. LEV I defined LEV and ULEV vehicles, and added TLEV and Tier 1 temporary classifications that would not be sold after 2003. LEV II added SULEV and PZEV vehicles, and LEV III tightened emission standards. The actual emission levels depend on the standards in use. •
LEV (Low Emission Vehicle): The least stringent emission standard for all new cars sold in California beyond 2004. •
ULEV (Ultra Low Emission Vehicle): 50% cleaner than the average new 2003 model year vehicle. •
SULEV (Super Ultra Low Emission Vehicle): These vehicles emit substantially lower levels of hydrocarbons, carbon monoxide,
oxides of nitrogen and particulate matter than conventional vehicles. They are 90% cleaner than the average new 2003 model year vehicle. LEV I defined emission limits for several different classes of vehicle, including passenger cars (PC), light-duty trucks (LDT), and medium-duty vehicles (MDV). Heavy-duty vehicles were specifically excluded from LEV I. LEV I also defined a loaded vehicle weight (LVW) as the vehicle's
Curb weight plus an allowance of . In general, the most stringent standards were applied to passenger cars and light-duty trucks with a LVW up to (these "light" LDTs were later denoted LDT1 under LEV II). Assembly Bill 32, better known as the California
Global Warming Solutions Act of 2006, codified these requirements. CARB filed a waiver request with the
United States Environmental Protection Agency (EPA) under Section 209(b) of the Clean Air Act in December 2005 to permit it to establish limits on greenhouse gas emissions; although the waiver request was initially denied in March 2008, it was later approved on June 30, 2009, after President
Barack Obama signed a Presidential Memorandum directing the EPA to reconsider the waiver. In the initial denial, EPA Administrator
Stephen L. Johnson stated the Clean Air Act was not "intended to allow California to promulgate state standards for emissions from new motor vehicles designed to address global climate change problems" and further, that he did not believe "the effects of climate change in California are compelling and extraordinary compared to the effects in the rest of the country." Johnson's successor,
Lisa P. Jackson, signed the waiver overturning Johnson's denial, writing that "EPA must grant California a waiver if California determines that its standards are, in the aggregate, at least as protective of the public health and welfare as applicable Federal standards." Jackson also noted that in the history of the waiver process, over 50 waivers had been granted and only one had been fully denied, namely the March 2008 denial of the GHG emissions regulation. CARB decided to adopt regulation of GHG emissions under Executive Order G-05-061, which provided phase-in targets for fleet average GHG emissions in -equivalent grams per mile starting with the 2009 model year. The calculation of -equivalent emissions was based on contributions from four different chemicals: , , , and
air conditioning refrigerants. The emissions in g/mi -equivalent are calculated according to the formula CO_2^\mathrm{equivalent} = CO_2 + 296\times N_2O + 23\times CH_4 - AC^\mathrm{direct} - AC^\mathrm{indirect}, which has two terms for direct and indirect emissions allowances of air conditioning refrigerants, depending on the refrigerant used, such as
HFC134a, and the system design. Vehicles powered by alternative fuels use a slightly modified formula, CO_2^\mathrm{equivalent} = (CO_2 + AC^\mathrm{indirect})\times F + 296\times N_2O + 23\times CH_4 + AC^\mathrm{direct}, where F is a fuel adjustment factor depending on the alternative fuel used (1.03 for natural gas, 0.89 for
LPG, and 0.74 for
E85). ZEVs are also required to calculate GHG as the processes to generate the energy (or fuel) used also produce GHG. For ZEVs, CO_2^\mathrm{equivalent} = U + AC^\mathrm{direct}, where U is the upstream emissions factor (130 g/mi for battery electric vehicles, 210 for hydrogen/fuel cell, and 290 for hydrogen/internal combustion). Manufacturers that do not wish to measure emissions may assume a value of 0.006 g/mi. CARB voted unanimously in March 2017 to require automakers to average for new cars in 2025.
Section 177 states Because California had emissions regulations prior to the 1977
Clean Air Act, under Section 177 of that bill, other states may adopt the more stringent California emissions regulations as an alternative to federal standards. Thirteen other states and the District of Columbia have chosen to do so, and ten of those have additionally adopted the California Zero-Emission Vehicle regulations. In December 2020, Minnesota announced its intention to adopt California LEV and ZEV rules; following a hearing before an
administrative law judge in February 2021, the Minnesota Pollution Control Agency adopted the California regulations. In August 2022, Virginia, citing to a 2021 law, announced it would follow California regulations for ZEV registrations. Arizona and New Mexico had previously adopted California LEV regulations under Section 177, but later repealed those states' clean car standards in 2012 and 2013, respectively. In Canada, the province of Quebec adopted CARB standards effective in 2010. CARB and the Government of Canada entered into a Memorandum of Understanding in June 2019 to cooperate on greenhouse gas emissions mitigation.
Zero-Emission Vehicle Program The CARB
Zero-Emission Vehicle (ZEV) program was enacted by the California government starting in 1990 to promote the use of zero emission vehicles. The program goal is to reduce the pervasive air pollution affecting the main metropolitan areas in the state, particularly in Los Angeles, where prolonged pollution episodes are frequent. The California ZEV rule was first adopted by CARB as part of the 1990 Low-Emission Vehicle (LEV I) Program. The focus of the 1990 rules (ZEV-90) was to meet air quality standards for
ozone rather than the reduction of greenhouse gas (GHG) emissions. Under LEV II in 1999, the ZEV regulations were moved to a separate section (13 CCR § 1962) and the requirements for ZEVs as a percentage of fleet sales was made more formal. Executive Order S-03-05 (2005) and Assembly Bills 1493 (2002) and 32 (2006) prompted CARB to reevaluate the ZEV program as last amended in 1996, which had been primarily concerned with reducing emissions of smog-forming pollutants. Since then, in September 2020 Governor
Gavin Newsom signed an executive order directing that by 2035, all new cars and passenger trucks sold in California will be zero-emission vehicles. Executive Order N-79-20 directs CARB to develop regulations to require that ZEVs be an increasing share of new vehicles sold in the state, with light-duty cars and trucks and off-road vehicles and equipment meeting the 100% ZEV goal by 2035 and medium and heavy-duty trucks and buses meeting the same 100% ZEV goal by 2045. The order also directs
Caltrans to develop near-term actions to encourage "an integrated, statewide rail and transit network" and infrastructure to support bicycles and pedestrians. In response, CARB began development of the Advanced Clean Cars II (ACC II) Program, focusing on emissions of vehicles sold after 2025. ACC II reiterated the aim to have all new passenger cars, trucks and SUVs sold in the state to be zero emissions vehicles by 2035, and was scheduled for consideration before CARB in June 2022. The regulations of ACC II were adopted by California in August 2022.
Vehicle definitions LEV I defined a ZEV as one that produces "zero emissions of any criteria pollutants under any and all possible operational modes and conditions." A vehicle could still qualify as a ZEV with a fuel-fired heater, as long as the heater was unable to be operated at ambient temperatures above and did not have any evaporative emissions. The ZEV regulation has evolved and been modified several times since 1990, and several new partial or low-emission categories were created and defined, including the introduction of PZEV and AT PZEV categories in ZEV-99.
ZEV credit system The LEV I rules also introduced the concept of emission credits. Under LEV I, the vehicle fleet average emissions rate of non-methane organic gases (NMOG) produced by a manufacturer was required to meet increasingly stringent requirements starting in 1994. According to comment responses, CARB determined that advanced batteries would not be ready in time to meet the ZEV requirements until at least 2003. In conjunction with relaxing the requirements in ZEV-96, CARB signed memoranda of agreement (MOAs) with the seven large scale manufacturers to begin rolling out demonstration fleets of ZEVs with limited public availability in the near term. The
GM EV1 was the first battery electric vehicle (BEV) offered to the public, in partial fulfillment of the agreement with CARB. The EV1 was available only through a /month lease starting in December 1996; the initial markets were South Coast, San Diego, and Arizona, and expanded to Sacramento and the Bay Area. GM also offered an
electric S-10 pickup truck to fleet operators.
Advanced Clean Cars The Low-Emission Vehicle Program was revised to define modified ZEV regulations for 2015 models. CARB estimates that ACC will result in 10% of all sales to be ZEVs by 2025. The share remained at 3% between 2014 and 2016. Battery vehicles receive 3 or 4 credits, while fuel cell cars receive 9. , a credit has a market value of $3-4,000, and some automakers have more credits than required. CARB held a public workshop in September 2020 where several new consumer-friendly regulations for ZEVs were proposed to improve adoption: • Standardization of a DC Fast Charge inlet (proposing to use
CCS Combo 1, with adapters provided by the vehicle manufacturer if applicable) • Standardization of vehicle and battery data (to assist assessment of need for repairs/condition) • Implement a standardized battery state-of-health (SOH) indicator (using SAE J1634 dynamometer testing to define battery capacity) and define a value of battery SOH that qualifies for warranty repair • Make ZEV powertrain service and repair information available to independent technicians and repair shops (including standardization of communication protocols for vehicle data) In May 2021, additional draft requirements were added: • Durability: BEVs to maintain 80% of certified range for 15 years/150,000 miles • Durability: FCEVs to maintain 90% of fuel cell system output power after 4,000 hours of operation • Battery Labelling: standardized content to improve the efficiency of recycling batteries to recover materials or potential repurposing To improve access to ZEVs, CARB added proposed environmental justice (EJ) credits in August 2021 for manufacturers who improve options for clean transportation to underserved communities, such as by providing a discount on a ZEV that would be used in a community-based clean mobility program. The August workshop also included additional regulations for ZEVs: • Range: starting in 2026, minimum (2-cycle) range to be • On-board charger: minimum 5.76 kW for AC (Level 2) charging, sufficient for a BEV to charge overnight (8 hours) from a 30A source The final workshop in October 2021 proposed that ZEVs would be taken out of fleet calculations for vehicle emissions and provided yearly targets for ZEV vehicle sales as a percent of total sales, including potential EJ credits. Additionally, the required warranty period and requirements to take credit for PHEV sales were defined: • Battery to retain ≥ 80% SoH for 8 years/100,000 miles • PHEVs to meet one of two requirements: • Transitional PHEVs (2026–28): minimum all-electric range with additional credit if vehicle exceeds on the US06 high speed/acceleration cycle; 8-year/100,000 80%SOH battery warranty, 5.76 kW on-board charger • Full credit PHEVs (2026+): minimum all-electric range, minimum on the
US06 high speed/acceleration cycle; 8-year/100,000 80%SOH battery warranty, 5.76 kW on-board charger • "Small volume" manufacturers (defined as those selling fewer than 4,500 cars per year) are required to comply with the ZEV mandate starting with the 2035 model year
OHV Emission Standards The California DMV implements the policy dictates of the California Air Resources Board (CARB) with respect to registration of off-highway motor vehicles (OHVs). Registration consists of ID plates or placards issued by the DMV. Operating a motorized vehicle off-highway in California requires either a Green Sticker or a Red Sticker ID. The Green Sticker indicates that the vehicle has passed emission requirements. The Red Sticker (issued through 2021) restricts OHV use due to not meeting emission standards established by the CARB. The red sticker program began in 1994 when CARB adopted standards for emissions from two-stroke engines used primarily on dirt bikes. Between 1998 and 2003, the red sticker program was refined allowing vehicles that did not meet peak ozone season standards to be operated only at specific times of the year. As of model year 2022, the CARB no longer authorizes issuing of red stickers.
Commercial Harbor Craft Regulation The California Air Resources Board's (CARB) Commercial Harbor Craft regulation is a regulatory framework aimed at reducing emissions from commercial vessels operating in California's harbors and ports. The rule primarily targets diesel-powered vessels such as ferries, tugboats, and other workboats that operate in and around California's ports. Since the original adoption of regulation in 2008, and its amendments in 2010 and 2022, vessel owners in the state have been required to either replace their engines or send their boats out of the state.
Low-carbon fuel standard The
Low-Carbon Fuel Standard (LCFS) requires
oil refineries and distributors to ensure that the mix of fuel they sell in the Californian market meets the established declining targets for
greenhouse gas emissions measured in
CO2-equivalent grams per unit of fuel energy sold for transport purposes. The 2007 Governor's LCFS directive calls for a reduction of at least 10% in the carbon intensity of California's transportation fuels by 2020. These reductions include not only
tailpipe emissions but also all other associated emissions from production, distribution and use of transport fuels within the state. Therefore, California LCFS considers the fuel's
full life cycle, also known as the "well to wheels" or "seed to wheels" efficiency of transport fuels. The standard is aimed to reduce the state's dependence on petroleum, create a market for clean transportation technology, and stimulate the production and use of alternative, low-carbon fuels in California. On April 23, 2009, CARB approved the specific rules for the LCFS that will go into effect in January 2011. The rule proposal prepared by its technical staff was approved by a 9–1 vote, to set the 2020 maximum carbon intensity reference value to 86 grams of carbon dioxide released per
megajoule of energy produced.
PHEV Research Center The
PHEV Research Center was launched with funding from the California Air Resources Board.
Innovative Clean Transit Under the Innovative Clean Transit (formerly known as the Advanced Clean Transit) regulation adopted in December 2018, public transportation agencies in California will gradually transition to a zero-emission bus fleet by 2040. Large transit agencies (defined as those operating more than 65 buses in the
San Joaquin Valley Air Basin or
South Coast Air Quality Management District, or those operating more than 100 buses elsewhere with populations greater than 200,000) are required to have 25% of new bus purchases as zero-emission buses (ZEBs) starting in 2023, 50% of new purchases as ZEBs starting in 2026, and 100% of new purchases as ZEBs starting in 2029. Small transit agencies are required to make 25% of new purchases as ZEBs in 2026 and 100% of new purchases as ZEBs in 2029+. Per the regulation, ZEBs are defined to include
battery electric buses and
fuel cell buses, but do not include electric
trolleybuses which draw power from overhead lines. The
Antelope Valley Transit Authority has set a goal to be the first all-electric fleet by the end of 2018, ahead of the tightened regulations. == Regulation of ozone produced by air cleaners and ionizers ==