Analysis of methods for estimating pollutant emissions from marine engines in terms of their use for evaluating ambient air quality

This paper discusses a method for estimating pollutant emissions from ICE of ships for air quality modelling. Three levels of emission estimation and methods for estimating ship pollutant emissions are divided into bottom-up and top-down approaches. The bottom-up approach is based on detailed ship operations and requires knowledge of many input parameters (a more accurate method but is very time-consuming). The top-down approach is based on the value of the fuel consumed by the ship and is less precise but more accessible to apply. Various data sources are available for estimating pollutant emissions from ships, including studies commissioned by the IMO, which provide reliable emission estimates for different types of ships but lack geospatial information; the CEDS database, which optimises regional emissions information by scaling emissions from ships to national levels; CAMS-GLOB-SHIP, which provides emissions at a resolution of 0,25° × 0,25° for the following substances: CO, NOx, VOC, EC, OC, BC, SOx, SO4; the EDGAR database, which provides annual emissions estimates at a resolution of 0.1° × 0.1°, but only covers the three main GHGs and F-gases; the Automatic Identification System (AIS), which provides high-resolution ship traffic data, allowing for a more realistic description of emitters. Many methods are available for estimating ship emissions, each with advantages and disadvantages. The choice of method depends on the available data and the level of accuracy required. The availability of AIS data allows for more accurate emission estimates, which is significant for a better understanding of the impact of shipping on air quality.