Emission inventory for harbour-related activities: comparison of two distinct bottom-up methodologies

Emission inventories are an essential tool for harbour authorities to assess the impacts of harbour-related activities and to assess the effectiveness of mitigation measures. In this paper, two bottom-up methodologies (EMEP/EEA and US/SCG) are applied to the Port of Leixões, Portugal, to develop an emission inventory for harbour-related activities, accounting for both the emissions from shipping and the cargo handling equipment. Emission estimates obtained from the two methodologies are compared and discussed. Regarding shipping emissions, the main disparities between the two methodologies arise from the differences in emission factors and application (or not) of fuel correction factors. Among the considered pollutants, EMEP/EEA methodology estimates higher total emissions (for all types of ship combined) of SO X , NO X , VOC, PM 2.5 , PM 10 , CH 4 , HC, CO and CO 2 (up to 46%), and lower emission of only N 2 O (up to 7%), comparing to US/SCG. Regarding CHE emissions, only EMEP/EEA methodology considers the deterioration factors adjustment, while the fuel correction factor is only considered for US/SCG methodology. Different emission factors also contribute to the observed differences in CHE emissions estimates, leading to higher total emissions (for all CHE combined) of NO X , CO, N 2 O, PM 2.5 , PM 10 , SO X and CO 2 (up to 85%), and lower emission of only CH 4 (264%), comparing to US/SCG. This paper provides a highly relevant approach to estimate CHE-related emissions in European ports and highlights the importance for a standardized methodology to estimate emissions from harbour activities, contributing not only to improve the scientific knowledge but also to provide support to harbour authorities, regarding the quantification of harbour’s environmental performance and the definition of mitigation measures.