Carbon Economy

Greenhouse gas (GHG) emissions in California decreased by 3.0% to 360.4 million metric tons (MMTCO2e) in 2023 compared to 2022. More importantly, emissions in 2023 remained 2.4% below emissions in 2020 during the COVID-19 pandemic shutdown — a notable achievement. While this data is encouraging and shows that California is still making progress, the state still needs to do more to meet its climate goals. SB 32 set a goal of reducing GHG emissions by 40% below 1990 levels by 2030, and at 360.4 MMTCO2e, the state’s 2023 emissions were only 17.6% below 1990 levels. The state now needs to reduce emissions at a rate of 4.4% per year to reach the 2030 target of 40% below 1990 levels, which is much higher than the annual rate of emissions reductions recorded historically. From 2019 to 2023, emissions fell at an average rate of just 2.8% per year. Further work will be needed to reduce emissions in harder-to-reach sectors such as transportation, buildings, and the industrial sector.

While the transportation sector remained the largest-emitter, accounting for 38.1% of total emissions in 2023, emissions fell by 4.6% compared to 2022 — the largest decrease of any sector. Electricity sector emissions have seen dramatic reductions since 2006. Emissions from in-state generation have decreased by 17.4% (-8.7 MMTCO2e) while emissions from imports decreased by 70.9% (-38.8 MMTCO2e). However, emissions from imports have declined significantly in recent years while emissions from in-state generation were higher in 2023 compared to 2020.

While most other sectors are not declining as quickly, they are moving in the right direction. For instance, emissions from the commercial sector fell by 1.5% and from the industrial sector by 3.7% from 2022 to 2023. The only sector in which emissions increased from 2022 to 2023 was the residential sector, where emissions grew by 6.8%. However, both the commercial and residential sectors are the only sectors where GHG emissions were higher in 2023 than in 2016, when California met the AB 32 goal of reducing GHG emissions to 1990 levels by 2020. The use of substitutes for ozone-depleting substances in refrigeration and air conditioning activities single-handedly accounts for the commercial sector’s increase in emissions.

Nationally, California was the third most carbon-efficient state (defined as GHG emissions relative to GDP), after New York and Massachusetts in 2023. Among the 50 states, only Maryland and Massachusetts had lower per-capita emissions than California in 2023 as well. The state has shown that it is possible to grow the economy, while lowering emissions. Compared to 1990, inflation-adjusted GDP per capita is up 101.2%, while GHG emissions per capita are down 36.6% in 2023. It will take more action, time, and resources to further decarbonize the economy, but the last couple decades offer hope that California can achieve its climate goals without sacrificing economic growth.

California’s Greenhouse Gas Emissions
  • Total greenhouse gas (GHG) emissions decreased by 11.2 million metric tons of carbon dioxide-equivalent (MMTCO2e) to 360.4 MMTCO2e in 2023—representing a 3% decrease compared to 2022.

  • The 2023 GHG emissions were 17.6% below the 1990 level of 431 MMTCO2e and 2.44% lower than the pandemic amount in 2020.

  • The transportation sector continues to be the largest-emitting sector in California, comprising 38.1% of the total emissions in 2023. This is down 4.6% (-6.6 MMTCO2e) from 2022.

  • Compared to the GHG emissions in 2022, among the economic sectors, the transportation sector experienced the largest reduction, decreasing by 4.6% (-6.6 MMTCO2e), followed by the electric power sector, which fell by 4.2% (-2.5 MMTCO2e).

  • Emissions from the industrial, agriculture, and commercial sectors decreased by 3.7% (-3.0 MMTCO2e), 2.9% (-0.9 MMTCO2e), and 1.5% (-0.4 MMTCO2e) respectively, from 2022 to 2023.

  • GHG emissions from the residential sector increased by 6.8% (+2.2 MMTCO2e) from 2022 to 2023.

  • The residential and commercial sectors were the only sectors where GHG emissions were higher in 2023 than in 2016 when California met the AB 32 goal of reducing GHG emissions to 1990 levels by 2020.

  • In comparison to the pre-pandemic 2019 emissions, the transportation sector has maintained its large declines and in 2023 emissions were 17.3% (-28.78 MMTCO2e) lower than 2019. The primary factor behind this trend is that the heavy-duty vehicles subsector GHG emissions did not rebound after the pandemic; falling 17.2% (-4.8 MMTCO2e) from 2022 to 2023, and remaining down 45.3% (-19.1 MMTCO2e) from 2006, the year AB 32 became law.

California’s Greenhouse Gas Emissions Reduction Progress and Outlook
  • Based on 2023 emissions, the state must reduce emissions by 4.4% each year to meet the SB 32 goal of 40% below 1990 levels by 2030. This is a slight increase compared to the 4.2% annual decrease required in 2022 and the 4.0% annual decrease required in 2021.

  • At the current annual average rate of reduction from 2019 to 2023 of 2.8% each year, the state would meet its 2030 goal in 2035.

  • From 2007 (when emissions peaked) to 2023, California has reduced emissions by 117.2 MMTCO2e and would need to reduce emissions by an additional 98.0 MMTCO2e to reach its SB 32 target by 2030 (or 27.2% from its 2023 levels).

  • California recently revised its emissions goal of 80% below 1990 levels by 2050 to 85% below 1990 levels by 2045. This means that even if California manages to meet the SB 32 target by 2030, the state would need to reduce its emissions at a pace of 8.8% per year to reach the goal by 2045—double the pace required to meet the 2030 target.

  • Using the average annual reduction of 2.8% from 2019 to 2023 instead, the average annual reduction rate would need to be 9.5% from 2030 to 2045 to meet the 2045 goal on time.

California’s Carbon Economy
  • In California, GHG emissions per capita fell by 2.8% (-0.27 MMTCO2e/person) from 2022 to 2023, while the state’s inflation-adjusted GDP per capita grew by 2.3% over the same time period.

  • Compared to 2019, GHG emissions per capita in 2023 were down by 9.7% (-0.99 MMTCO2e/person), while the inflation-adjusted GDP per capita in 2023 was up by 10.4%.

  • From 2013 to 2023, California’s energy intensity decreased by 32.8%, ahead of all other most populous states: Texas (-26.5%), Pennsylvania (-29.0%), New York (-18.0%), Florida (-31.0%), Massachusetts (-32.3%) and Michigan (-26.6%).

  • In addition to performing well in terms of carbon intensity, California also has one of the lowest energy-related GHG emissions per capita levels, with 8.3 MMTCO2e per person in 2023—edging out every other big state including New York (8.4 MMTCO2e per person), which historically had slightly lower per capita emissions than California.

  • From 2022 to 2023, the carbon intensity of California’s energy supply (CO2 relative to British thermal unit) dropped 2.9%, while that of the U.S. decreased by 1.7%.

Greenhouse Gas Emissions by Sector: Challenges & Opportunities
  • Within the transportation sector, emissions from on-road vehicles, which make up 90% of transportation’s emissions, were 4.2% (-21.3 MMTCO2e) lower in 2023 than in 2022. Within the on-road vehicles sub-sector, emissions from heavy-duty vehicles declined by 17.2% (-4.8 MMTCO2e) from 2022 levels, while emissions from passenger vehicles declined by 0.6% (-0.6 MMTCO2e).

  • Emissions from other transportation subsectors (aviation, rail, ships, other, and not specified) fell by 8.4% (-1.2 MMTCO2e), from 2022 to 2023.

  • The majority of the recent decreases in transportation sector emissions came from the heavy-duty vehicles sector, which fell by over a quarter (-8.6 MMTCO2e or -27.1%) in just two years from 2021.

  • Distillate (diesel) fuel combustion from heavy-duty trucks accounted for the lion’s share of reduction in heavy-duty vehicle subsector’s emissions, falling 27.1% (-5.1 MMTCO2e) from 2022 to 2023.

  • The GHG emissions per unit of transportation fuel consumed were 6.28 MMTCO2e/hundred trillion BTU in 2023, down 2.9% from 2022.

  • Californians exported or sent 41.8 million tons of waste to landfills in 2023, up 2.3 million tons (+5.9%) from 39.5 million tons in 2022 and up 12.5 million tons (+42.7%) compared to the 29.3 million tons in 2012.

  • After years of relatively little changes in landfill emissions, the combined emissions from included emissions and from biogenic materials exceeded 14 MMTCO2e for the first time in 2023.

  • Emissions from the use of substitutes for ozone-depleting substances (SODS), which emit high global warming potential (GWP) gases such as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), are the fastest-growing source of GHG emissions in California.

  • In 2023, GHG emissions from SODS from all economic sectors accounted for 5.8% of total included statewide emissions, up from 5.6% in 2022 and the highest ever.

  • By end-use sectors, in 2023, emissions from SODS fell in the transportation sector (-4.3%) and industrial sector (-0.6%) compared to 2022 but rose in the residential sector (+6.1%) and the commercial sector (+0.3%).

  • From 2007 to 2023, the residential sector’s share of emissions from SODS has risen from 7.3% to 25.9%, and from 30.9% to 44.7% for the commercial sector.

  • From 2008 to 2023, emissions from the commercial retail sub-sector rose by 24.0% and emissions from the industrial solid waste treatment from composting activities increased by 49.4%.