Impacts of Autonomous Vehicles on Greenhouse Gas Emissions-Positive or Negative?

Moneim Massar,Syed Masiur Rahman,Sheikh Muhammad Habib Abdullah,Fahad Saleh Al-Ismail,Arshad Jamal,Imran Reza

doi:10.3390/ijerph18115567

Abstract

The potential effects of autonomous vehicles (AVs) on greenhouse gas (GHG) emissions are uncertain, although numerous studies have been conducted to evaluate the impact. This paper aims to synthesize and review all the literature regarding the topic in a systematic manner to eliminate the bias and provide an overall insight, while incorporating some statistical analysis to provide an interval estimate of these studies. This paper addressed the effect of the positive and negative impacts reported in the literature in two categories of AVs: partial automation and full automation. The positive impacts represented in AVs’ possibility to reduce GHG emission can be attributed to some factors, including eco-driving, eco traffic signal, platooning, and less hunting for parking. The increase in vehicle mile travel (VMT) due to (i) modal shift to AVs by captive passengers, including elderly and disabled people and (ii) easier travel compared to other modes will contribute to raising the GHG emissions. The result shows that eco-driving and platooning have the most significant contribution to reducing GHG emissions by 35%. On the other side, easier travel and faster travel significantly contribute to the increase of GHG emissions by 41.24%. Study findings reveal that the positive emission changes may not be realized at a lower AV penetration rate, where the maximum emission reduction might take place within 60–80% of AV penetration into the network.

Highlights

According to the United Nations Framework on Climate Change Convention, the transportation sector was responsible for 27% of US greenhouse gas (GHG) emissions in2010 [1]
While comparing the GHG emissions from autonomous vehicles (AVs) to its counterpart, fossil fuel vehicles (FFV) may have different attribute levels, this review study is only limited to the realm that both AVs and FFVs are only operated on fossil fuels
It is believed that reductions in GHG emissions through AVs’ adoption will be negated to an unascertained extent, mainly due to increased car travel, facilitated by other factors such as lower perceived travel time and costs per km/trip, probable loss of public transport patronage, and possible increases in car ownership

Summary

Introduction

According to the United Nations Framework on Climate Change Convention, the transportation sector was responsible for 27% of US greenhouse gas (GHG) emissions in2010 [1]. GHGs are one of the leading causes of the greenhouse effect worldwide [2] They serve as artificial heat-trapping agents within the earth’s atmosphere. Gaseous emissions resulting from burning these energy sources include methane (CH4 ), carbon dioxide (CO2 ) and nitrous oxide (N2 O), which can last in the planet’s atmosphere for several decades, causing continuous global warming [3]. These unregulated GHGs emissions disturb the natural gas cycles governing the planet and pose a significant threat to various flora and fauna types [4].

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Methods

Conclusion