Spatial Analysis of the Ship Gas Emission Inventory in the Port of Busan Using Bottom-Up Approach Based on AIS Data

Analysis of the uncertainty of the AIS-based bottom-up approach for estimating ship emissions

Although the AIS-based bottom-up approach has become the dominant method for estimating ship emissions, there are still inherent uncertainties due to the numerous complex factors involved. This paper aims to investigate the development process of the AIS-based bottom-up approach and identify the primary sources of uncertainty by conducting a systematic review of 29 articles published since 2015. The result shows three sources of uncertainty for estimating ship emissions, i.e., the acquisition and processing of AIS data, ship characteristic information and engine load calculation, and the determination of emission factors. This paper suggests that the accuracy of ship emission inventories can be improved by enhancing the reliability of datasets, uniformly defining engine load calculation formulas, and making more extensive measurements of local emissions to provide substantial support for ship emissions management and facilitate the development of more effective emission reduction strategies.

Diverse changes in shipping emissions around the Western Pacific ports under the coeffect of the epidemic and fuel oil policy

The Western Pacific Ocean (the WPO), as one of the busiest shipping areas in the world, holds a complex water traffic network. In 2020, the International Maritime Organization (IMO) low-sulfur fuel regulations were implemented globally, while the COVID-19 outbreak influenced shipping activities together. This study aimed to assess the combined impact of epidemics and low-sulfur fuel policies on ship emissions, as well as their environmental effects on the WPO. The ship emission model based on the Automatic Identification System (AIS) data was applied to analyze the monthly emission variations during 2018-2020. It was found that the epidemic had obvious diverse influences on the coastal ports in the WPO. Overall, shipping emissions declined by 15 %-30 % in the first half of 2020 compared with those in 2019 due to the COVID-19 lockdown, whereas they rebounded in the second half as a result of trade recovery. The pollutants discharged per unit of cargo by ships rose after the large-range lockdown. China's multiphase domestic emission control areas (DECAs) and the IMO global low-sulfur fuel regulation have greatly reduced SO₂ emissions from ships and caused them to "bypass and come back" to save fuel costs around emission control areas from 2018 to 2020. Based on satellite data and land-based measurements, it was found that the air quality over sea water and coastal cities has shown a positive response to changes in ship-emitted NO_x and SO₂. Our results reveal that changes in shipping emissions during typical periods, depending on their niches in the complex port traffic network, call for further efforts for cleaner fuel oils, optimized ECA and ship lane coordination in the future. Shipping related air pollutions during the later economic recovery also needs to be addressed after international scale standing-by events.

Methodology to Assess the Technoeconomic Impacts of the EU Fit for 55 Legislation Package in Relation to Shipping

The recent inclusion of shipping in the Fit for 55 legislation package will have large knock-on effects on the industry and consequently on end consumers. The present paper presents an innovative top-down methodology, the MSF455 model, which estimates the new vessel Operational Expenditure (OPEX) as per the provisions of the Fit for 55 package and various scenarios based on carbon tax, penalty allowances, maritime fuel tax and effect. The methodology is presented and tested against six scenarios that are based on Det Norske Veritas’s (DNV) fuel maritime projections. The model illustrates that the distinction between intra-EU and extra-EU penalty allowance creates a large disparity and thus reduction in the competitiveness of goods (produced and transported).

Estimation of the Efficiency of Vessel Speed Reduction to Mitigate Gas Emission in Busan Port Using the AIS Database

To mitigate marine atmospheric pollution causing greenhouse gas (GHG) and a threat to coastal residents’ health in dense hub port cities, the Vessel Speed Reduction (VSR) programs were implemented in the Republic of Korea. Spatial analysis of the efficiency of the VSR programs is essential to monitor and improve the present programs. In the present study, the efficiency of the VSRs from the Busan Port (BP), including North Port (NP) and Gamcheon Port (GP), were analyzed. A bottom-up activity-based approach using automatic identification system (AIS) data was introduced herein for the estimation of spatial marine gas emission in real time. The BP has implemented the VSR program since 2020; thus, this study spatially analyzed marine gas emissions in the areas in 2019 and 2020 to demonstrate the efficiency of VSR. To demonstrate the VSR programs in the aspect of the comparison of gas emissions in each year, the total annual fuel consumption in each year is divided by the total arrival ships’ GT respectively. According to the comparison of the spatial gas emission inventory between two years in the designed area, 19.2% of the annual marine gas emissions per ships’ GT in BP in 2020 were reduced with the implementation of the VSR program. The spatial analysis clearly showed the mitigation of the ships’ gas emissions along the passageway to BP. The spatial analysis of the efficiency of the VSR program will be useful basic data to reflect the local gas emission state on the improvement of the VSR program and newly established environmental regulations.