2050 UK shipping emissions of NOx, SOx, PM10, and PM2.5: What are the determining factors, is the zero pollution by 2050 feasible, and will the reduction rate for these pollutants be at the same pace?

This study investigates 2050 UK shipping emissions for NOx, SOx, PM₁₀ & PM_2.5, to assess the determining factors, feasibility of zero pollution, and whether the emission reduction will progress at the same pace. The 2016 UK shipping emissions was used as the baseline scenario, with 2025 UK shipping energy demand expectedly the same as that of 2016. Three fuel-mix-scenarios were analysed: one dominated by e-fuels (Scenario 1), one dominated by biofuels (Scenario 2), and a central case (Scenario 3). By applying the pollutants' emission factors to these scenarios, the range of the projected 2050 UK total shipping emissions in kilotons were NOx (307-942), SOx (4-7), and 1-8 for both PM10 and PM2.5. Compared to the 2016 scenario, the total emission reduction rates for NOx, SOx, PM₁₀ and PM_2.5, respectively were ‐27, 95, 99, and 99 % for Scenario 1; 25, 96, 87, and 87 % for Scenario 2; and 59, 97, 52, and 52 for Scenario 3. These findings revealed that achieving zero pollution in the sector for these pollutants by 2050 is not feasible, their emission reduction rates will not progress at the same pace, and that certain fuel mix which favour carbon emission reduction, will invariably increase NOx emission. Further analysis revealed that two key factors—fuel mix type and energy demand—will significantly influence these emissions. Consequently, new fuel scenarios incorporating more of hydrogen fuel are proposed, yielding promising results. Therefore, increased proportion of hydrogen fuel, coupled with technologies for individual pollutant reduction will help address these emissions.