satellite data clearly reveals visible shipping patterns (Supple- mentary Fig. 11). Consequently, it can be stated that emissions from OGVs provide the dominant factor in the observed NO2 VCD data. When looking at the average NO2 levels before and after the implementation of the NECA for the different areas, it was demonstrated that NO2 levels after the introduction of the NECA were impacted in different ways. The BAQPZJR area remained the most polluted area, with the English Channel following closely behind. However, since the implementation of the NECA, the Bay of Biscay became the third most polluted area, before the Northern NECA. Temporal analysis of atmospheric NO2 data. For the temporal analysis of NO2, an annual and a monthly approach was used. For the annual approach, the proportional difference between 2019 Fig. 7 Spatiotemporal analysis—impact global sulfur cap. Annual proportional difference of SO2 VCD levels between 2019 and 2021. Fig. 8 Impact NECA on NOx. Box plot of annual NO2 VCD levels between different areas before (BFNC) and after (AFNC) the European NECA entered into force in 2021, with minimum, 25% percentile, median, 75% percentile and maximum. ARTICLE COMMUNICATIONS EARTH & ENVIRONMENT | https://doi.org/10.1038/s43247-023-01050-7 8 COMMUNICATIONS EARTH & ENVIRONMENT | (2023) 4:391 | https://doi.org/10.1038/s43247-023-01050-7 | www.nature.com/commsenv