Although at its face the results seem obvious, a recent study by [Sandrah Eckel] et al. on the impact of electric cars in California is interesting from a quantitative perspective. What percentage of ICE-only cars do you need to replace with either full electric or hybrid cars before you start seeing an improvement in air quality?
A key part of the study was the use of the TROPOMI instrument, part of the European Sentinel-5 Precursor satellite. This can measure trace gases and aerosols in the atmosphere, both of which directly correlate with air quality. The researchers used historical TROPOMI data from 2019 to 2023 in the study, combining this data with vehicle registrations in California and accounting for confounding factors, such as a certain pandemic grinding things to a halt in 2020 and massively improving air quality.
Although establishing direct causality is hard using only this observational data, the researchers did show that the addition of 200 electric vehicles would seem to be correlated to an approximate 1.1% drop in measured atmospheric NO2. This nitrogen oxide is poisonous and fatal if inhaled in large quantities. It’s also one of the pollutants that result from combustion, when at high temperatures nitrogen from the air combines with oxygen molecules. Continue reading “Correlating Electric Cars With Better Air Quality”






