Solar panels

EPIC

San Diego Regional Greenhouse Gas Emissions Outlook and Gap Analysis

Historical and Projected Regional GHG Emissions

The San Diego region has made significant progress towards reducing greenhouse gas (GHG) emissions since regional emissions tracking began in 2012, achieving a 35% emissions reduction from 2012 to 2022. Progress in the passenger vehicle and electricity sectors contributed most significantly to this reduction.

2022 GHG Emissions Key Facts

35%

Reduction in overall GHG emissions compared to 2012

34%

Reduction in GHG emissions from passenger vehicle compared to 2012

60%

Reduction in GHG emissions from electricity consumption compared to 2012

4%

Reduction in GHG emissions from natural gas consumption compared to 2012

35%

Reduction in GHG emissions from solid waste disposal compared to 2012

Full realization of the 2025 San Diego Regional Climate Action Roadmap (“Regional Roadmap”) — in conjunction with achieving California state targets for electric vehicle (EV) sales and the Renewable Portfolio Standard (RPS) — would be required for the San Diego region to meet the targets aligned with statewide SB 32 and come close to reaching AB 1279 reduction targets for the primary inventory sectors. The primary inventory sectors, as established by ICLEI’s U.S. Community Protocol, include emissions from in-region transportation in light-duty vehicles, electricity consumption, natural gas consumption, solid waste disposal, water consumption, and wastewater generation. These primary inventory sectors were outlined as priorities for local and regional governments to assess and prioritize emissions reduction policies due to the relative influence local agencies have to affect emissions in those public-serving sectors, as well as the data availability to track progress.

However, when looking at emissions from an economy-wide perspective (i.e., including additional in-region sectors such as industrial gases, livestock and agricultural activities, heavy-duty vehicles, aviation, marine vessels, rail transportation, and off-road vehicles and equipment) an emissions reduction gap persists. Further work is required across these remaining sectors though much of the regulatory authority for these sectors lies with agencies outside of the San Diego region. Use the “Select Target Line” toggle in the Regional Emissions Scenario Tool below to see how emissions targets change depending on the inventory sectors included in the analysis.

Gap Analysis Summary

Sectors Included in Analysis: Emissions from in-region transportation in light-duty vehicles, electricity consumption, natural gas consumption, solid waste disposal, water consumption, and wastewater generation

Projected Ability to Reach Reduction Targets: All Regional Roadmap measures, pre-statewide EV waiver revocation EV targets to be met in the region, and Renewable portfolio standards must be met to reach SB32 targets. Small gap to reach AB1279 targets.

Critically, as illustrated by the emissions scenario tool below, if the state mandated EV sales and RPS goals fall short in the future years, the San Diego region would fall short of meeting regional overall targets, thereby increasing the relative importance and impact of local and regional GHG mitigation efforts.

Regional Emissions Scenario Tool

San Diego’s economy-wide emissions have decreased 36% below 2012 levels, from 34 million metric tons carbon dioxide equivalent (MMT CO2e) to 22 MMT CO2e in 2022. With current California state laws and regulations, and regional GHG reduction measures outlined in the 2025 Regional Climate Action Roadmap, estimated emissions could decline further to 12 MMT CO2e by 2045, a reduction of 64% below 2012 emissions.

California reduced emissions levels to 1990 levels in inventory year 2016, so in absence of regional greenhouse gas data from 1990, the inventory year of 2016 can be used as a proxy for understanding how the region is making progress towards the targets in SB 32 and AB 1279. Using this approach, the region reduced emissions 16% below 2016 levels in 2022. When including the state laws and regulations, and a full implementation of Regional Roadmap measures, the region could reduce estimated economy-wide emissions 53% below 2016 levels by 2045. As previously mentioned, because the region relies heavily on the state actions, failure to meet state-mandated EV sales and RPS goals would create a significant shortfall in meeting the overall regional targets.

View the uncertainty in the Regional Emissions Scenario Tool dashboard by adjusting the key parameters. Notice the relative change in emissions reductions by policy due to the adjustments made.

Full realization of California’s EV sales goals before recent federal action assumed an EV penetration rate of approximately 75% by 2045. In CARB’s adjusted projections (EMFACv2.1.0, March 2026), EV penetration rate assumption has been adjusted to 42% by 2045.

Historical and Projected Economywide Greenhouse Gas Emissions in the San Diego Region

How do Local Climate Action Plan (CAP) Commitments Compare to the Regional Roadmap?

While the Regional Roadmap brings a first of its kind regional perspective of the policies needed for economy-wide emissions reduction, local governments in the region have integrated climate action planning into the city planning process in the past decades.

The Roadmap and local Climate Action Plans (CAPs) are different in several ways, even though both have GHG reduction targets and policies to reduce GHG emissions. Local CAPs are adopted by local jurisdictions, and focus on GHG emissions from primary inventory sectors and reduction measures within the local jurisdictional controls. The Roadmap addresses economy-wide emissions across the entire San Diego region, including sources within and outside local jurisdictional controls, and reduction measures typically require local and regional agency partnership.

For the GHG-emitting sectors covered in both CAPs and the Regional Roadmap, the dashboard below compares the emissions reduction policies that local governments in the region have committed to through their CAPs to the Regional Roadmap, and the emissions reductions in the target years 2030 and 2045.

All Regional CAP Commitments by Measure Type

Local CAP Commitments

The dashboard below shows a variety of GHG reduction policies and commitments in different local CAPs.


Implementation Challenges and Opportunities in Achieving Long-term Emission Reduction Goals

The following sections, which represent the primary GHG emitting sectors that are covered in both the Regional Roadmap and local CAPs, summarize implementation challenges and opportunities each sector faces in achieving long-term emission reduction goals. Potential changes at the federal government level in recent years created headwinds in the region to meet these reduction goals. However, the following sections also include emerging state policies and programs that would have positive impacts at the regional level, and additional actions that local jurisdictions could take.

On-Road Transportation Sector

Main Drivers of Progress to Date

Main drivers of progress in the on-road transportation sector to date are a decoupling of vehicle miles travelled and GHG emissions; VMT has reduced about 10% since 2012 and emissions reduced about 34% due to vehicle emission standards. This is due to vehicle efficiency and electrification.

Passenger Vehicles Activity and Emissions

  • 2012
    • Passenger Vehicle Miles Traveled 0.01%
    • Emissions from Passenger Vehicles 0.01%
  • 2016
    • Passenger Vehicle Miles Traveled -1%
    • Emissions from Passenger Vehicles -21.1%
  • 2022
    • Passenger Vehicle Miles Traveled -10%
    • Emissions from Passenger Vehicles -40.8%

Federal and State Impacts on Local Climate Action Goals

Barriers

Opportunities

Local Opportunities for Progressing Towards Goals

Electricity Sector

Main Drivers of Progress to Date

We have also seen a decoupling of electricity consumption and emissions - electricity consumption has reduced by 20% and emissions have reduced by almost 60% since 2012. This is due to increased zero-emission electric generation sources. Achieving overall emissions targets will require significant electrification of the transportation and building sectors, which will increase consumption. Since the emissions per unit of electricity is declining, the net effect of this transition should be lower overall emissions.

Electricity Consumption and Emissions

  • 2012
    • Electricity Consumption 0.01%
    • Emissions from Electricity 0.01%
  • 2016
    • Electricity Consumption -2.2%
    • Emissions from Electricity -27.1%
  • 2022
    • Electricity Consumption -18.1%
    • Emissions from Electricity -59.2%

Federal and State Impacts on Local Climate Action Goals

Barriers

Local Opportunities for Progressing Towards Goals

Natural Gas Sector

Main Drivers of Progress to Date

The emissions associated with burning natural gas remain constant when compared to the amount of gas burned; therefore, the emissions and therms of natural gas burned follow the same trajectory. The region has reduced natural gas consumption and correlating emissions by 4% from 2012 to 2022.

Natural Gas Consumption and Emissions

  • 2012
    • Natural Gas Consumption and Emissions 0.01%
  • 2016
    • Natural Gas Consumption and Emissions -11.1%
  • 2022
    • Natural Gas Consumption and Emissions -12.9%

Federal and State Impacts on Local Climate Action Goals

Barriers

Opportunities

Local Opportunities for Progressing Towards Goals

Solid Waste Sector

Main Drivers of Progress to Date

According to the most recent waste characterization study (statewide study done in 2021), the reduction in organic waste to landfill driven by SB 1383 resulted in a regional emissions reduction of 35% from waste sent to landfill, despite a 26% increase in total tonnage sent to landfill.

Solid Waste Generation and Emissions

  • 2012
    • Tons to Landfill 0.01%
    • Emissions from Solid Waste 0.01%
  • 2016
    • Tons to Landfill 20.6%
    • Emissions from Solid Waste 20.6%
  • 2022
    • Tons to Landfill 26.3%
    • Emissions from Solid Waste -34.5%

Federal and State Impacts on Local Climate Action Goal

Barriers

While there have not been recent regulatory barriers that negatively impact solid waste reduction, significant hurdles exist in the industry including:

  • Economic barriers in the recycling industry due to low landfill costs
  • Regulatory hurdles for community composting and their ability to be self-sufficient given stringent franchise hauling agreements
  • Economic disincentives at the customer level to reduce waste or recycle

Opportunities

CalRecycle estimates that the organic recycling capacity of the region is met. Therefore, to reach organics recycling goals remaining issues would have to be addressed, including ensuring haulers have expanded service to all customer types, increasing customer participation rates, and decreasing contamination rates.

Local Opportunities for Progressing Towards Goals

Other Economy-Wide Sectors

The colored sectors in this remaining emissions chart represent emissions that are largely outside of the direct regulatory reach of San Diego local and regional authorities. Despite these constraints on authority, local and regional governments can have some influence through indirect levers:

Emerging Technology - Carbon Dioxide Removal

Some local jurisdictions have adopted net zero GHG emissions goals in their CAPs to be consistent with state law. After accounting for all GHG reduction measures, these CAPs typically have remaining emissions. To reach net zero emissions, it would be necessary to remove from the atmosphere an amount equal to remaining emissions. Learn more in the carbon dioxide removal (CDR) Primer on what CDR is, current methods and their characteristics, and the role CDR plays in reaching long-term GHG emissions targets.

Resources

Access Our Full Resource Library (14 Primers & Briefs)

Acknowledgement

Thank you to our project sponsor: The San Diego Foundation

San Diego Foundation Logo

Thank you to the following organizations: During the course of the project, we conducted interviews to gain perspectives and feedback from representatives of the following organizations:

Climate Action Campaign, City of Carlsbad, City of Chula Vista, City of Del Mar, City of Vista, County of San Diego, San Diego Association of Governments (SANDAG), San Diego Community Power/San Diego Regional Energy Network, SD350, Sierra Club, San Diego Building Electrification Coalition


EPIC Staff:

Scott Anders, Executive Director
Joe Kaatz, Senior Staff Attorney
Yichao Gu, Senior Policy Analyst
Naomi Wentworth, Technical Policy Analyst

Disclaimer

The Energy Policy Initiatives Center (EPIC) developed this webpage and content with the support from the San Diego Foundation. This webpage and content represents EPIC’s professional judgment based on the data and information available at the time of the project. EPIC relies on data and information from third parties who provide it with no guarantees such as of completeness, accuracy or timeliness. EPIC makes no representations or warranties, whether expressed or implied, and assumes no legal liability for the use of the information in this webpage; nor does any party represent that the uses of this information will not infringe upon privately owned rights. Readers of the webpage are advised that EPIC may periodically update the webpage or data, information, findings, and opinions and that they assume all liabilities incurred by them, or third parties, as a result of their reliance on the report, data, information, findings and opinions contained in the webpage.