Using high-resolution emissions inventories, integrated atmospheric models, and health risk functions, the study assessed ship-related PM2.5 pollution impacts in 2020 with and without the use of low-sulphur fuels.
More specifically, the study finds that prior to cleaner ship fuels, ship-related health impacts include ~400,000 premature deaths from lung cancer and cardiovascular disease and ~ 14 million childhood asthma cases annually. Reduced PM2.5 from marine engine combustion mitigates ship-related premature mortality and morbidity by 34 and 54%, respectively.
What is more, reduced aerosol radiative cooling attributable to ship emissions accompanies health benefits from lower-sulphur fuels. Cleaner fuels reduce radiative cooling from ship aerosols by ~80% (71 mW m−2) due to lower direct aerosol cooling (−3.9 mW m−2) and lower cloud albedo (−67 mW m−2). Local intensities of these changes in health and climate directly relate to the major patterns of ship traffic along major trade routes and continental coastlines.
More than 97% of the adult mortality benefits from ship emissions reductions will be in Asia (80%), Africa (12%), and Latin America and the Caribbean (5%). More than 98% of the childhood morbidity benefits from ship emissions reductions also occur in Asia (54%), Africa (33%), and Latin America and the Caribbean (12%). The different distributions are primarily due to the different distributions of adult and youth populations among nations.
Europe, North America, and Oceania combined will receive <3% and <2% of the mortality and morbidity benefits of the global sulphur standard, respectively. This is primarily due to existing legislation (with or without the global standards) in North America, the Baltic Sea, the North Sea, the English Channel, and EU sea areas in general.
The study was initially published in Nature Communications Journal and conducted by the Atmospheric Composition Research, Finnish Meteorological Institute, the Rochester Institute of Technology, Rochester, NY, the Energy and Environmental Research Associates, LLC, Pittsford, and the University of Delaware, 305 Robinson Hall, Newark.