ALTERNATIVE TRAJECTORIES FOR DECARBONIZING URBAN TRANSPORTATION

The document argues that without major intervention, transportation carbon emissions will double by 2050. It identifies a combination of reduced passenger car demand, improved vehicle efficiency, increased electric vehicle adoption, and a decarbonized electricity grid (via renewables, nuclear, or CCS) as the necessary path to significant reductions. A case study based on a Spanish city with 360,000 inhabitants demonstrates that while modal shifts and fuel switches (like CNG or biodiesel) offer modest gains, the most aggressive reductions occur when these are paired with a transition to nuclear or CCS-equipped power generation.

• The transportation sector is a significant source of global greenhouse gas emissions, contributing approximately one-quarter (about 7 GtCO2) of annual releases, with road transport accounting for 75% of that total.
• In the absence of new climate policies, transport-related carbon emissions are projected to double by 2050 compared to 2010 levels.
• For light-duty vehicles, the mitigation potential by 2050 is approximately 5 GtCO2, with an average carbon cost of 26 $2006 per tonne of CO2.
• A case study of a Spanish urban area with 360,000 inhabitants shows that a 25% modal shift from cars to public transport combined with switching buses from diesel to CNG or biodiesel reduces aggregate carbon emissions by only 10%, while absolute emissions still grow by 36% to 64% by 2050.
• The most significant carbon reductions in the case study are achieved through an 'aggressive' scenario involving a 50% reduction in car use, 50% improvement in fuel economy, and high penetration of HEV/BEV technologies; this results in 2050 emissions being 22% lower than 2010 levels with current electricity, or 49% lower if CCS is used.
• Decarbonizing the electricity supply is critical for transport emissions; nuclear-based electricity scenarios yielded the lowest aggregate emissions in the analysis, reducing 2050 absolute emissions by 55% compared to 2010.
• Air pollution from transport, specifically fine particulate matter (PM2.5) and ozone (O3), causes significant mortality, with the Global Burden of Disease Study 2010 attributing 3.2 million annual deaths to PM2.5 and 0.15 million to O3.

APA

Spadaro, J. V., Faria, S. H., & Markandya, A. (2013). ALTERNATIVE TRAJECTORIES FOR DECARBONIZING URBAN TRANSPORTATION. Basque Centre for Climate Change. https://www.bc3research.org/h6T8Uy8Nm4gFs0O/2013112109495459910748.pdf

Chicago

Spadaro, Joseph V., Sérgio H. Faria, and Anil Markandya. ALTERNATIVE TRAJECTORIES FOR DECARBONIZING URBAN TRANSPORTATION. Basque Centre for Climate Change, 2013. https://www.bc3research.org/h6T8Uy8Nm4gFs0O/2013112109495459910748.pdf.

Wikipedia

{{cite report |last1=Spadaro |first1=Joseph V. |last2=Faria |first2=Sérgio H. |last3=Markandya |first3=Anil |title=ALTERNATIVE TRAJECTORIES FOR DECARBONIZING URBAN TRANSPORTATION |publisher=Basque Centre for Climate Change |date=November 2013 |url=https://www.bc3research.org/h6T8Uy8Nm4gFs0O/2013112109495459910748.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{spadaro2013alternative, author = {Spadaro, Joseph V. and Faria, Sérgio H. and Markandya, Anil}, title = {{ALTERNATIVE TRAJECTORIES FOR DECARBONIZING URBAN TRANSPORTATION}}, institution = {Basque Centre for Climate Change}, year = {2013}, month = nov, url = {https://www.bc3research.org/h6T8Uy8Nm4gFs0O/2013112109495459910748.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }