Abstract Emissions have been a critical concern for the shipping sector, calling for climate mitigation measures to be implemented in this field urgently. It is therefore useful to understand the factors that influence the relevant empirical trends so that policies can be better tailored to address the climate challenges. Given the high reliance on fossil fuels, this paper has focused on the energy consumption from international shipping, by examining 6 factors across product types and shipping routes. This is based on comprehensive microdata of almost all vessels in the world over 2014–2017. The study finds that improvements in energy intensity is consistent across product types and shipping routes, reinforcing the importance of energy efficiency as a key climate mitigation measure. However, shifts in freight transport activity across different regions have offset gains in energy efficiency and was the most dominant factor contributing to an increase in energy consumption. Monitoring of the transport structure effect is critical for progress tracking and the potential of this effect to alter energy consumption should also be factored into emission projections.