Global vessel carbon dioxide emission from navigable rivers

Abstract

Inland water vessels are a substantial but poorly quantified source of transport-sector CO2 emissions. Using approximately 20 billion automatic identification system records and a trajectory completion algorithm, we provide a global high-resolution assessment of inland vessel CO2 emissions. These vessels emitted 164.0 ± 1.58 TgCO2 in 2022, equivalent to 24.7% of global waterborne vessel emissions, despite operating on only 0.4% of the global navigable marine and inland water surface area. Emissions are concentrated within a few hotspot river corridors and exhibit baseline-dependent amplification (2019–2022) together with seasonal variability. These patterns reflect the combined effects of transport demand and hydroclimatic constraints on navigability. Because inland water vessel emissions occur within river corridors where riverine CO2 evasion is also active, they represent an important anthropogenic carbon source and may influence river–atmosphere CO2 exchange. These results provide a basis for improving inland transport emission inventories and informing targeted mitigation strategies under climate change. The magnitude and distribution of CO2 emissions from river transport are poorly constrained. This study finds that global CO2 emissions from inland vessels were about one-quarter of total vessel emissions, and that emissions were concentrated in the Northern Hemisphere, related to economic activity.