Estimation of greenhouse gas emissions from ships registered in South Korea based on activity data using the bottom-up approach

The shipping sector is one of the major contributors to greenhouse gas (GHG) emissions. We aimed to calculate GHG emissions categorized by ship type for all vessels registered in South Korea. Hence, for the first time in South Korea, a bottom-up method based on ship activity data was employed, estimating energy consumption and emissions by ship type. Data from ships registered from 2019 to 2021 were collected and reclassified by ship type, and operational profiles were developed. Based on these profiles, the emissions of major GHGs, including CO2, CH4, and N2O, were estimated for the 3-year period. Cargo ships accounted for the highest percentage of annual fuel consumption, approximately 62.7%–64.7% of the total fuel consumption for all ships. The GHG emissions were calculated to be an average of 4.644 million tonCO2e, which is approximately 6.5 times higher than those from oil tankers (0.710 million tonCO2e), the second-highest emitter. This highlights the need for intensified GHG reduction measures specifically targeting cargo ships, providing clear evidence for prompt and enhanced implementation. The research findings are expected to be utilized as substantiated data for developing specific and systematic GHG reduction policies tailored to each ship type.