European shipping emissions guidebook: Methodology improvement recommendations for more accurate estimations and inventorying

The maritime sector is a significant contributor to greenhouse gases and air pollutant emissions, accounting for approximately 3% of global CO 2 emissions in 2018, a figure expected to rise to 17% by 2050. To address these challenges, the authorities put forward initiatives for reducing emissions through technical and operational strategies. Accurate emissions estimation is critical for evaluating the impact of these measures and technologies on emissions reductions. The main method used in the EU for maritime emissions inventorying and projections is the European Monitoring and Evaluation Programme/European Environment Agency (EMEP/EEA) air pollutant emission inventory guidebook methodology. This study identifies key limitations in the current European shipping guidebook methodology, which has not been updated since 2010, and proposes enhancements improving accuracy and relevance. Utilizing a dataset of around 15,000 vessels trading in European ports, the analysis reveals the need to expand ship categories from nine to nineteen to reflect the current fleet profile. The study proposes updates to technical and operational parameters, like main and auxiliary engine specifications, speed profiles, engine loads and operational phase durations. The inclusion of the anchorage phase in emissions calculations is also recommended to address emissions near port areas. Validation against MRV-reported emissions demonstrates that the recommended approach reduces CO 2 estimation deviations from 52.1% to 12.3% compared to the original methodology, with improvements for other harmful air pollutants. Such updates will assist stakeholders in devising better targeted emissions reduction strategies and align the European guidebook with advancements in maritime technologies and operational practices. • Fleet in European ports during 2022: 15,000 ships analyzed • Proposed ship categories for introduction in methodology expanded from 9 to 19 • Updates reduce CO 2 deviations from 52.1% to 12.3% compared to official database • Anchorage phase inclusion in emission calculations is recommended • Better estimates of climate-relevant and air pollutant emissions