Air Quality and Climate Impacts of Alternative Bus Technologies in Greater London

Abstract

The environmental impact of diesel-fueled buses can potentially be reduced by the adoption of alternative propulsion technologies such as lean-burn compressed natural gas (LB-CNG) or hybrid electric buses (HEB), and emissions control strategies such as a continuously regenerating trap (CRT), exhaust gas recirculation (EGR), or selective catalytic reduction with trap (SCRT). This study assessed the environmental costs and benefits of these bus technologies in Greater London relative to the existing fleet and characterized emissions changes due to alternative technologies. We found a >30% increase in CO2 equivalent (CO2e) emissions for CNG buses, a <5% change for exhaust treatment scenarios, and a 13% (90% confidence interval 3.8-20.9%) reduction for HEB relative to baseline CO2e emissions. A multiscale regional chemistry-transport model quantified the impact of alternative bus technologies on air quality, which was then related to premature mortality risk. We found the largest decrease in population exposure (about 83%) to particulate matter (PM2.5) occurred with LB-CNG buses. Monetized environmental and investment costs relative to the baseline gave estimated net present cost of LB-CNG or HEB conversion to be $187 million ($73 million to $301 million) or $36 million ($-25 million to $102 million), respectively, while EGR or SCRT estimated net present costs were $19 million ($7 million to $32 million) or $15 million ($8 million to $23 million), respectively.

How are the Two Most Polluted Metro-cities of India Combating Air Pollution? Way Forward after Lifting of COVID-19 Lockdown

“…(Cui et al, 2020). The similar post-policy accomplishment of reduced air pollution and GHG as co-benefit was reported for Greater London, UK (Chong et al, 2014), Yogyakarta, Indonesia (Dirgahayani, 2013); Bangkok Metropolitan Area, Thailand (Li and Crawford-Brown, 2011); Mexico City, Mexico; Khon Khaen, Thailand; Beijing, China; Bogota, Colombia (Labriet et al, 2009).…”

Mapping the co-benefits of climate change action to issues of public concern in the UK: a narrative review

“…In particular, diesel vehicles are responsible for high levels of particulate matter and nitrogen oxides, which are known to cause and exacerbate respiratory-related illness. 11 Decarbonising the transport sector by improving the fuel efficiency of vehicles and transitioning from vehicles powered by petrol and diesel to electricity and hydrogen 12 have the potential to make considerable improvements to air quality across the UK, 13 consequently reducing health-care costs and NHS expenditure.…”

How Can Urban Policies Improve Air Quality and Help Mitigate Global Climate Change: a Systematic Mapping Review

“…47 Of the four articles based in the UK, all of them are situated in London. 43,[50][51][52] The high number of studies for Delhi and Beijing reflects the severity of the air pollution situation, as they are two of the world's most polluted cities. On the other hand, London is considered a pioneer in the implementation of control policies for reducing vehicular urban air pollution.…”