Effects of ship emissions on global and regional aerosol distributions for future low-sulfur scenarios

Kurzfassung

Ocean-going ships are responsible for a large fraction of the total fuel consumption by transportation-related activities. Ships are the largest source of SO2 emissions of all transportation modes and also emit large amounts of NOx and CO2 (Eyring et al., 2010). Recent regulations enacted by the International Maritime Organization (IMO) are now aiming at reducing the maximum sulfur content in marine fuels from currently 4.5% down to 0.5% in 2020. More restrictive limits have been set for coastal shipping routes close to densely populated regions (IMO, 2009). In this study, we perform simulations with the global aerosol-climate model EMAC-MADE to analyze the impact of ship emissions on air quality. Here, we focus on particulate matter, which is known to have adverse effects on human health. We analyze different scenarios of low-sulfur fuel applications in shipping (Righi et al., 2011), including the use of biofuels, to estimate changes in the global and regional aerosol distributions. We find that regulations coming fully into force in 2020 and the consequent use of low-sulfur fuels in shipping lead to strong reductions in surface-level particle concentrations particularly along the most travelled routes. This would improve air quality near the coastlines of Northern Europe, the Western Pacific region and Southeast Asia significantly.