What is it about?
This paper looks at how CO₂ emissions from global transport have changed between 1850 and 2020. It examines what drove these changes, separating the effects of population, economic growth, demand for transport, and improvements in energy efficiency. Using a new long-term dataset, the study shows how rising transport activity has shaped emissions over time and how efficiency gains have influenced the trend.
Featured Image
Photo by John Cameron on Unsplash
Why is it important?
The results show that efficiency improvements reduced emissions significantly, but this was more than offset by growth in transport demand. This means that improving technology alone is unlikely to be enough to reduce emissions. Understanding the balance between efficiency and demand helps policymakers design more realistic strategies for decarbonizing transport, including the scale and speed of electrification needed.
Perspectives
This paper is part of the project World Primary-Final-Useful (WPFU) Energy and Exergy Database from 1800 to 2020 The WPFU project develops a long-run global database of primary, final and useful energy and exergy flows across sectors and technologies. The database reconstructs energy conversion chains over the last two centuries in order to analyse technological transitions, efficiency improvements, and the evolution of energy services. By combining historical energy data with societal exergy analysis, the project enables researchers to study the relationships between energy use, efficiency, economic development, and long-term energy transitions. Related papers: Pinto, R., Brockway, P.E., Domingos, T., Sousa, T, 2026. Long run electricity consumption in computing: exponential growth followed by stabilisation due to efficiency gains. iScience, 114876 Tostes, B., Henriques, S., Heun, M. K., T., Brockway, P. B. and Sousa, T, 2025. Global Transport Emissions 1850–2020: Historical Drivers and Lessons for Transport Decarbonization. Transportation Research Part D: Transport and Environment, 148, 104998. Tostes, B., Heun, M. K., Henriques, S. T., Brockway, P. B. and Sousa, T, 2025. Insights from the evolution of transport technologies, 1800-2020: Energy use, transitions, and efficiency. Applied Energy, 401, Part A, 126561. Tostes, B., Henriques, S. T., Brockway, P. E., Heun, M. K., Domingos, T., Sousa, T, 2024. On the right track? Energy use, carbon emissions, and intensities of world rail transportation, 1840–2020, Applied Energy, 367, 123344. Pinto, R., Henriques, S.T., Brockway, P.E., Heun, M. K., Sousa, T, 2023. The rise and stall of world electricity efficiency: 1900–2017, results and insights for the renewables transition. Energy, 269, 126775. Steenwyk, P., Heun, M. K., Brockway, P.E., Sousa, T, Henriques, S.T, 2022. The Contributions of muscle and machine work to land and labor productivity in world agriculture since 1800. Biophysical Economics and Sustainability, 7: 2.
Assistant Professor Tânia A. Sousa
Instituto Superior Técnico
Read the Original
This page is a summary of: Global transport emissions 1850–2020: Historical drivers and lessons for transport decarbonization, Transportation Research Part D Transport and Environment, November 2025, Elsevier,
DOI: 10.1016/j.trd.2025.104998.
You can read the full text:
Contributors
The following have contributed to this page
