Search

[Display omitted] • Timeline of real driving passenger car emissions (1998 to 2022) in the UK constructed from remote sensing data. • Impact of the promotion and demise of diesel fuel on passenger car NO x emissions evaluated. • Promotion of diesel fuel in the UK led to 721 kt excess NO x emissions. • Rapid move away from diesel fuel had minor influence on UK emissions. The promotion and growth in the use of diesel fuel in passenger cars in the UK and Europe over the past two decades led to considerable adverse air quality impacts in urban areas and more widely. In this work, we construct a multi-decade analysis of passenger car emissions in the UK based on real driving emissions data. An important part of the study is the use of extensive vehicle emission remote sensing data covering multiple measurement locations, time periods, environmental conditions and consisting of over 600,000 measurements. These data are used to consider two scenarios: first, that diesel fuel use was not promoted in the early 2000s for climate mitigation reasons, and second, that there was not a dramatic decline in diesel fuel use following the Dieselgate scandal. The strong growth of diesel fuel use coincided with a time when diesel NO x emissions were high and, conversely, the strong decrease of diesel fuel use coincided with a time when diesel vehicle after-treatment systems for NO x control were effective. We estimate that the growth in diesel car use in the UK results in excess NO x emissions of 721 kt over a three decade period; equivalent to over 7 times total annual passenger car NO x emissions and greater than total UK NO x emissions of 681.8 kt in 2021 and with an associated damage cost of £5.875 billion. However, the sharp move away from diesel fuel post-Dieselgate only reduced NO x emissions by 41 kt owing to the effectiveness of modern diesel aftertreatment systems. [ABSTRACT FROM AUTHOR]

Cities across the globe recognise their role in climate mitigation and are acting to reduce carbon emissions. Knowing whether cities set ambitious climate and energy targets is critical for determining their contribution towards the global 1.5 °C target, partly because it helps to identify areas where further action is necessary. This paper presents a comparative analysis of the mitigation targets of 327 European cities, as declared in their local climate plans. The sample encompasses over 25% of the EU population and includes cities of all sizes across all Member States, plus the UK. The study analyses whether the type of plan, city size, membership of climate networks, and its regional location are associated with different levels of mitigation ambition. Results reveal that 78% of the cities have a GHG emissions reduction target. However, with an average target of 47%, European cities are not on track to reach the Paris Agreement: they need to roughly double their ambitions and efforts. Some cities are ambitious, e.g. 25% of our sample (81) aim to reach carbon neutrality, with the earliest target date being 2020.90% of these cities are members of the Climate Alliance and 75% of the Covenant of Mayors. City size is the strongest predictor for carbon neutrality, whilst climate network(s) membership, combining adaptation and mitigation into a single strategy, and local motivation also play a role. The methods, data, results and analysis of this study can serve as a reference and baseline for tracking climate mitigation ambitions across European and global cities. • 78% of cities have a mitigation plan with targets (avg. 47% GHG reduction). • Only 25% of cities strive for carbon neutrality, most by 2050, avg. By 2045. • 90% of cities striving for carbon neutrality are members of a climate network. • Ambition is driven by city size, climate networks, M-A combination, local motivation. • European cities must double their ambitions to meet the aims set by the Paris Agreement. [ABSTRACT FROM AUTHOR]