Diesel passenger vehicle shares influenced COVID-19 changes in urban nitrogen dioxide pollution

Abstract

Diesel-powered vehicles emit several times more nitrogen oxides than comparable gasoline-powered vehicles, leading to ambient nitrogen dioxide (NO2) pollution and adverse health impacts. The COVID-19 pandemic and ensuing changes in emissions provide a natural experiment to test whether NO2 reductions have been starker in regions of Europe with larger diesel passenger vehicle shares. Here we use a semi-empirical approach that combines in-situ NO2 observations from urban areas and an atmospheric composition model within a machine learning algorithm to estimate business-as-usual NO2 during the first wave of the COVID-19 pandemic in 2020. These estimates account for the moderating influences of meteorology, chemistry, and traffic. Comparing the observed NO2 concentrations against business-as-usual estimates indicates that diesel passenger vehicle shares played a major role in the magnitude of NO2 reductions. European cities with the five largest shares of diesel passenger vehicles experienced NO2 reductions ∽2.5 times larger than cities with the five smallest diesel shares. Extending our methods to a cohort of non-European cities reveals that NO2 reductions in these cities were generally smaller than reductions in European cities, which was expected given their small diesel shares. We identify potential factors such as the deterioration of engine controls associated with older diesel vehicles to explain spread in the relationship between cities' shares of diesel vehicles and changes in NO2 during the pandemic. Our results provide a glimpse of potential NO2 reductions that could accompany future deliberate efforts to phase out or remove passenger vehicles from cities.

The Apple Mobility Trends Data in Human Mobility Patterns during Restrictions and Prediction of COVID-19: A Systematic Review and Meta-Analysis

“…Based on the four exclusion criteria, 16 reports were excluded. One report had no COVID-19 context [ 36 ], four did not point to the geographical region where it was conducted [ 37 , 38 , 39 , 40 ], eight studies did not describe how the mobility data was used [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ], and three were not relevant [ 49 ]. Thirty-five reports were left in the review.…”

Reconsidering gas as clean energy: Switching to electricity for household cooking to reduce NO2-attributed disease burden

“…The development of zero-carbon technologies is in line with global efforts to combat climate change [ 48 ], as evidenced by the commitment of 65 countries and major sub-national economies to achieve net-zero greenhouse gas emissions by 2050 at the 2019 Climate Action Summit. Compared to the decarbonization efforts made by various countries in the transportation and power sectors, which were estimated to reduce atmospheric NO x concentrations by 19%–80% in China [ 49 , 50 ] and by 3%–60% in Europe [ 51 ] at the same time, household gas consumption has received little attention in the energy sector owing to its low energy consumption share. However, switching from gas stoves to electric stoves can significantly reduce the disease burden associated with NO 2 from a public health perspective.…”