skip to content

MPhil in Engineering for Sustainable Development

global challenges, engineering solutions

Sustainable mobility: Exploring barriers and opportunities for carsharing in urban California

Climate change is causing an increase in natural disasters in California, such as raging wildfires, and droughts. The state is projected to exceed its 2045 net-zero targets by around 125 MtCO2e, which will require the removal of CO2 from the air, costing about $10 billion per year. In 2019, the transportation sector contributed 39.7 percent and was the biggest source of carbon emissions in California, with LDVs responsible for 71.7 percent of those emissions. The core strategy adopted by state agencies is to reduce GHG emissions by transitioning to an EV fleet, which is projected to increase total vehicles by 43 percent between 2017-2045, while population growth is expected to be 11 percent. Moreover, the use of Plug-In Hybrid EVs in this transition does not guarantee reduced emissions as users may operate them in gasoline mode depending on various factors. The embodied and disposal emissions for EVs, resource-intensive battery production methods and poor working conditions for miners are some other concerns with the current strategy. In addition, the current policies can increase the Vehicle Miles Travelled and the Vehicle Hours of Delay in California by up to 32.5 percent and 100 percent by 2045, compared to 2020, respectively, contradicting other state goals.

One way to reduce emissions is through carsharing, where people rent cars for short periods. The existing research examines the environmental benefits of carsharing per member or vehicle but does not investigate the combined benefits in emissions reduction if the services were to grow in the future in California. Hence, this dissertation investigates how a transition to carsharing can reduce emissions till 2045 through regression analyses and scenario-based 3D modelling. The research found that 9.5 vehicles are removed from the roads per shared vehicle and that consumers drive 43 percent less after joining the services. Results from 3D modelling suggest that even a small 10 percent mix of shared vehicles in the total fleet by 2045 can help California significantly towards its net-zero goal. Due to uncertainty with emerging technologies, a sensitivity analysis was performed, by varying the number of vehicles removed per shared vehicle. The proposed mathematical models and research will be used as a reference to assess the impact of carsharing on GHG emissions in meeting California’s net-zero target. Policymakers can use the results for urban planning in transport and to better leverage positive impacts and ESG sector financiers can use the emissions data for sustainable investment purposes in emerging mobility.


Course Overview


The need to engage in better problem definition through careful dialogue with all stakeholder groups and a proper recognition of context.


An ability to work with specialists from other disciplines and professional groups acknowledging that technical innovation and business skills also must be understood, nurtured and combined as precursors to the successful implementation of sustainable solutions.


An understanding of mechanisms for managing change in organisations so future engineers are equipped to play a leadership role.


An awareness of a range of assessment frameworks, sustainability metrics and methodologies such as Life Cycle Analysis, Systems Dynamics, Multi-Criteria Decision making and Impact Assessment.