Do Electric Vehicles Mitigate Urban Heat? The Case of a Tropical City

Gianluca Mussetti,Juan A Acero,Edouard L Davin,Jordan Ivanchev,Sonia I Seneviratne,Vivek Kumar Singh,Luxi Jin,Jonas Schwaab

doi:10.3389/fenvs.2022.810342

Abstract

On top of their well known positive impact on air quality and CO2 emissions, electric vehicles generate less exhaust heat compared to traditional vehicles thanks to their high engine efficiency. As such, electric vehicles have the potential to mitigate the excessive heat in urban areas—a problem which has been exacerbated due to urbanisation and climate change. Still, the heat mitigation potential of electric vehicles has not been fully understood. Here, we combine high-resolution traffic heat emission inventories with an urban climate model to simulate the impact of the fleet electrification to the near-surface air temperature in the tropical city of Singapore. We show that a full replacement of traditional internal combustion engine vehicles with electric vehicles reduces the near-surface air temperature by up to 0.6°C. The heat mitigation potential is highest during the morning traffic peak and over areas with the largest traffic density. Interestingly, the reduction in exhaust heat emissions due to the fleet electrification during the evening traffic peak hardly leads to a reduction of near-surface air-temperatures, which is attributed to the different atmospheric conditions during morning and evening. This study presents a new quantification of the city-wide impact of electric vehicles on the air temperature in a tropical urban area. The results may support policy-makers toward designing holistic solutions to address the challenge of climate change adaptation and mitigation in cities.

Highlights

The combined effect of climate change and the urban heat island challenges the living conditions in cites, with consequences on human health, the economy and ecosystems (Revi et al, 2014)
The results of this study indicate that the full fleet electrification (FE) produces a reduction in near-surface air temperature, which is moderate at the daily scale but substantial during the morning traffic peak
The estimated heat mitigation potential of electric vehicles (EVs) is lower than what found by Li et al (2015) but on the same order of what found by Singh et al (2022)

Summary

Introduction

The combined effect of climate change and the urban heat island challenges the living conditions in cites, with consequences on human health, the economy and ecosystems (Revi et al, 2014). Cities are asked to take an active role in mitigating their contribution to global warming and associated climate change by reducing their CO2 emissions (Hsu et al, 2020). They need to implement local measures to adapt to warmer conditions (hereinafter heat mitigation), which are inevitable even with the most optimistic CO2 emission pathways (IPCC, 2014). Anthropogenic heat emissions are produced by building heating, ventilation and cooling (HVAC), vehicular traffic and human metabolism (Sailor, 2011; Sun et al, 2018). The urban climate impact of measures on vehicular traffic is yet mostly unexplored (Zhu et al, 2017)

Methods

Results

Conclusion