Keeping cities green: Avoiding carbon lock-in due to urban development

The paper examines how urban development decisions regarding buildings and transport infrastructure can 'lock in' future greenhouse gas emissions. By comparing a reference scenario with an aggressive 'urban action' scenario, the authors estimate that urban policy-makers can avoid committing approximately 45 Gt CO2 of cumulative future emissions by 2030 through energy-efficient technologies and compact urban design. The analysis emphasizes that current infrastructure already commits roughly 800 Gt CO2, meaning the 1,000 Gt CO2 global carbon budget for limiting warming to 2°C could be exceeded before 2020 if current trends continue.

• Under a reference scenario based on current trends and plans, new urban infrastructure is expected to commit approximately 14 Gt CO2 of future emissions annually over the next 15 years, totaling more than 220 Gt CO2 by 2030.
• An aggressive 'urban action' scenario involving compact urban forms and high-efficiency standards could reduce annual emissions commitments to 8.5 Gt CO2 by 2030, avoiding approximately 45 Gt CO2 of cumulative future emissions compared to the reference case.
• Urban buildings are the primary driver of carbon lock-in, accounting for over 70% (nearly 10 Gt CO2 annually) of future emissions commitments in urban areas. A significant portion of this is driven by appliances and lighting, particularly in non-OECD countries, which represent about 70% of those specific commitments by 2030.
• Urban transport infrastructure commits about 4 Gt CO2 annually in the reference scenario. Roughly half of this is attributed to the expansion of urban form and sprawling road networks, with 80% of these specific commitments occurring in non-OECD countries.
• Existing global infrastructure built before 2015 has already committed approximately 800 Gt CO2. When combined with new annual commitments from urban (14 Gt) and non-urban (34 Gt) infrastructure, the total global carbon budget of 1,000 Gt CO2 may be exceeded before 2020.
• Implementing stringent energy performance standards for new buildings is significantly more cost-effective than later retrofitting; the marginal cost for new buildings is less than 10 USD/t CO2, whereas retrofitting can cost 50 USD/t CO2 or more.

APA

Erickson, P., & Tempest, K. (2015). Keeping cities green: Avoiding carbon lock-in due to urban development. Stockholm Environment Institute. https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2015-11-C40-Cities-carbon-lock-in.pdf

Chicago

Erickson, Peter, and Kevin Tempest. Keeping cities green: Avoiding carbon lock-in due to urban development. Stockholm Environment Institute, 2015. https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2015-11-C40-Cities-carbon-lock-in.pdf.

Wikipedia

{{cite report |last1=Erickson |first1=Peter |last2=Tempest |first2=Kevin |title=Keeping cities green: Avoiding carbon lock-in due to urban development |publisher=Stockholm Environment Institute |date=October 2015 |url=https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2015-11-C40-Cities-carbon-lock-in.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{erickson2015keeping, author = {Erickson, Peter and Tempest, Kevin}, title = {{Keeping cities green: Avoiding carbon lock-in due to urban development}}, institution = {Stockholm Environment Institute}, year = {2015}, month = oct, url = {https://www.sei.org/mediamanager/documents/Publications/Climate/SEI-WP-2015-11-C40-Cities-carbon-lock-in.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }