The ELK global emission inventory for the transport sectors

Abstract. The transport sectors, comprising land transport, shipping and aviation, are major contributors to climate change and have a detrimental impact on air quality, with adverse consequences for human health. The emissions from transport, already contributing 23 % of total anthropogenic CO₂ emissions in 2019, are projected to continuously grow in the future, challenging the achievement of climate protection and pollution reduction targets. A major goal of transport research on climate and air quality is the accurate assessment of its impacts, which requires detailed emission data to drive atmospheric models and calculate projections for future scenarios. This paper presents the ELK global emission inventory for the transport sectors. The inventory is developed using a consistent bottom-up approach fed with a wide range of input data to model the transport fleets of land transport, shipping and aviation. It provides several major improvements over existing datasets, such as the explicit resolution of the emissions at the subsector level, the consideration of transport-specific quantities and emission species, and the quantification of the transport-related emissions from the energy sectors. The emission data is complemented by a quantitative uncertainty score, based on a detailed expert-judgement analysis along the modelling chain, from the activity data to the emission factors. The emission data is validated by comparing it with other, well-established global inventories, and biases are discussed and, where possible, explained in terms of the different assumptions and features of the underlying emission models. The ELK dataset is released under an open-source licence to encourage their use in the atmospheric modelling community.