Shipping emissions forecast in the Iberian Peninsula for 2050 impact on air quality, mortality and related costs

The International Transport Forum projected that global demand for transport could triple by 2050, with shipping demand likely increasing even more rapidly. However, most scenarios for the next 20-30 years suggest that current regulatory policies may be insufficient to offset the rise in traffic. Thus, this study evaluates the impacts of shipping emissions on air quality, health, and external costs in the Iberian Peninsula, analysing past (2017), current (2022), and projected future (2050) scenarios. Using high-resolution emissions data, it was assessed the influence of existing regulations, including the IMO 2020 sulphur cap and a hypothetical implementation of the shore-side electricity (SSE) in the major ports of the Iberian Peninsula, and project future impacts under a business-as-usual scenario for 2050. Results indicate significant improvements in air quality from the IMO sulphur cap, with reductions in NO₂, SO₂, and particulate matter (PM_2.5 and PM₁₀) concentrations, mainly near the Strait of Gibraltar. SSE implementation showed localized air quality benefits near ports, although a slight O₃ increase was verified due to atmospheric interactions (NO_x titration). PM_2.5 shipping related emissions exposure resulted in approximately 1 061 premature deaths and 3 626 years of life lost (YLL) between 2017 and 2022, with economic costs of 9.1 billion € for the Iberian Peninsula. Projections for 2050 suggested that although the fleet efficiency is expected to increase and Tier III compliance mitigate emissions, the rising population density and aging will likely lead to more premature deaths and YLL, totalling 4 459 deaths and 68 081 YLL, with costs reaching 53.2 billion €. According to these results, regulatory actions, including potential Atlantic Ocean ECA implementation, are recommended to offset the combined effects of demographic changes and shipping traffic growth in the future.