San Francisco

The urban mobility emissions trajectory is moving in the right direction, but more efforts are needed for the city to achieve the 1.5°C target by 2030.

City dashboard (2022)
Population 0.8 million
Surface area (km2) 120
Mobility demand (km) 13 billion
Mobility demand per person per day (km) 45.7
Mobility emissions (CO2e) 1.3 megatons
Emissions per person per day (CO2e) 4.29 kilograms

Urban mobility global warming impact (2030)

[i]
Based on cities’ existing action plans
5°C 3°C 1°C
Target 0.0°C

0.0°C

City trajectory
Target 1.5°C

Emissions reductions required to reach the 1.5°C target by 2030

-0%

0.0MtCO2e

[i]
Megatons of Carbon Dioxide Equivalent (MtCO2e)


Introduction

San Francisco has a well-balanced mobility network that offers a variety of options

San Francisco offers a great mix of mobility services, with a balanced modal share between cars (59%), public transit (31%), walking (6%), and other modes. Mobility demand in San Francisco accounted for 13 billion kilometers (8 billion miles) traveled in 2022, generating 1.2 MtCO2e.

Despite car-free zones, hundreds of kilometers of bike lanes, and a good public transit system, more than half of the distance traveled in 2022 in San Francisco was via cars, contributing to 86% of city mobility emissions.

To boost public transit use, the city has launched the Bay Area Transit-Oriented Affordable Housing (TOAH) Fund, providing $40 million to promote equitable transit-oriented development across nine counties. It provides financing for the development of affordable housing, community services, fresh food markets, and other facilities near transit lines.

Mobility demand and emissions (2022)

Demand
Emission

Current situation

San Francisco is on the right path to reaching the Paris Agreement goals, but further drops in emissions are necessary

Based on city plans, mobility demand is expected to grow by 7% by 2030 while CO2 emissions are forecasted to decrease by 20%. San Francisco has been at the forefront of decarbonization, having achieved a 41% emission reduction six years ahead of schedule. In 2021, Mayor London Breed set a more ambitious target, reducing emissions by 61% by 2030 (below 1990 levels) to become carbon-neutral by 2040.

Current mobility trends predict that electric vehicles will continue to increase in market share because of San Francisco’s plan for electric vehicles making up at least a quarter of registered private vehicles and 80% of trips to be low carbon by 2030. San Francisco also aims to have electric vehicles account for 100% of private vehicle traffic by 2040. Additionally, California banned the sale of new gasoline-powered cars by 2035.

However, San Francisco’s commitments to address transport emissions are still roughly 0.3 MtCO2e short of the target, requiring an additional 11% decrease in emissions on top of current government commitments by 2030 to stay within 1.5°C of warming.

Mobility demand (by mode) and emissions trajectory (2022-2030) 

Mobility demand per mode
Total mobility emission

Optimization

How San Francisco can fulfill the Paris Agreement commitments by 2030

We explored four different optimization scenarios:

  • Default: Minimizes mobility behavior changes
  • Electrification: Accelerates the transition from gasoline and diesel vehicles to electric vehicles
  • Multimodal: Encourages the use of shared services and public transit
  • Active Mobility: Promotes walking and cycling as alternative modes of transport

All the optimization scenarios get San Francisco to the 1.5°C target and require only limited shifts in behavior or small reductions in projected demand, thanks to the city’s ambitious blueprint. All four scenarios are a good fit for San Francisco, but the default, multimodal, and electrification scenarios would require smaller behavioral changes than the active mobility scenario.

  • Default*
  • Electrification*
  • Multimodal*
  • Active Mobility

* indicates the scenarios that achieve the greatest realistic emissions reduction

Modal Shifts Required To Achieve 1.5°C (By Scenario)

When simulating realistic modal shifts, achieving 1.5°C would be possible, and would not require a reduction in total mobility demand compared to 2022.

Reduce personal car use:

  • Expand existing car-free areas and institute low-emissions zones
  • Introduce barriers to personal cars (for example, congestion pricing, limited parking)

Boost public transport:

  • Utilize the Bay Area Transit-Oriented Affordable Housing (TOAH) Fund to boost public transit ridership
  • Continue investments in public transit infrastructure and consider further incentivizing public transit fares

Increase active mobility:

  • Promote active mobility by implementing the 15-minute city concept
  • Continue investing in walking infrastructure, cycling infrastructure, and bicycle sharing programs by working within the San Francisco Active Communities Plan (ACP), which will finish in May 2024

Modal Shifts Required To Achieve 1.5°C (By Scenario)

When simulating realistic modal shifts, achieving 1.5°C would be possible, and would not require a reduction in total mobility demand compared to 2022.

Reduce personal car use:

  • Expand existing car-free areas and institute low-emissions zones
  • Introduce barriers to personal cars (for example, congestion pricing, limited parking)

Accelerate electrification of the fleet:

  • Accelerate fleet electrification (cars and buses) to swiftly achieve San Francisco's Electric Mobility Implementation Plan goal of 100% greenhouse gas-free transportation by 2040

Increase active mobility:

  • Promote active mobility by implementing the 15-minute city concept
  • Continue investing in walking infrastructure, cycling infrastructure, and bicycle sharing programs by working within the San Francisco Active Communities Plan (ACP), which will finish in May 2024

Modal Shifts Required To Achieve 1.5°C (By Scenario)

When simulating realistic modal shifts, achieving 1.5°C would be possible, and would not require a reduction in total mobility demand compared to 2022.

Reduce personal car use:

  • Expand existing car-free areas and institute low-emissions zones
  • Introduce barriers to personal cars (for example, congestion pricing, limited parking)

Boost public transport:

  • Utilize the Bay Area Transit-Oriented Affordable Housing (TOAH) Fund to boost public transit ridership
  • Continue investments in public transit infrastructure and consider further incentivizing public transit fares

Promote shared mobility:

  • While San Francisco has many existing opportunities for shared scooters, mopeds, bikes, and cars, consider soliciting new market entrants
  • Expand the number of Bay Wheels shared bike stations to more locations and consider further incentivizing fares

Modal Shifts Required To Achieve 1.5°C (By Scenario)

When simulating realistic modal shifts, achieving 1.5°C would be possible, and would not require a reduction in total mobility demand compared to 2022.

Reduce personal car use:

  • Expand existing car-free areas and institute low-emissions zones
  • Introduce barriers to personal cars (for example, congestion pricing, limited parking)

Increase walking:

  • Promote active mobility by implementing the 15-minute city concept
  • Continue investing in walking infrastructure, cycling infrastructure, and bicycle sharing programs by working within the San Francisco Active Communities Plan (ACP), which will finish in May 2024

Increase cycling:

  • Continue investing in cycling road infrastructure and overall accessibility, such as improving bike- sharing incentives, building e-bike charging stations, and setting up non-e-bike parking stations