Global typology of urban energy use and potentials for an urbanization mitigation wedge

TLDR

Urban mitigation potential for climate change is poorly understood, and projected urban energy use could triple from 240 EJ in 2005 to 730 EJ in 2050, with policy effectiveness varying by city type. The study aims to show that urban planning and transport policies can cap future urban energy use at 540 EJ by 2050, thereby mitigating climate change. Using data from 274 cities worldwide, the authors model how economic activity, transport costs, geography, and urban form explain 37 % of direct and 88 % of transport energy use. The model finds that policies can cap urban energy use at 540 EJ by 2050, with higher gasoline prices and compact form saving energy in affluent cities, while compact form and transport planning in developing cities can raise densities and avoid high‑carbon travel, underscoring a major urbanization wedge in rapidly urbanizing regions.

Abstract

The aggregate potential for urban mitigation of global climate change is insufficiently understood. Our analysis, using a dataset of 274 cities representing all city sizes and regions worldwide, demonstrates that economic activity, transport costs, geographic factors, and urban form explain 37% of urban direct energy use and 88% of urban transport energy use. If current trends in urban expansion continue, urban energy use will increase more than threefold, from 240 EJ in 2005 to 730 EJ in 2050. Our model shows that urban planning and transport policies can limit the future increase in urban energy use to 540 EJ in 2050 and contribute to mitigating climate change. However, effective policies for reducing urban greenhouse gas emissions differ with city type. The results show that, for affluent and mature cities, higher gasoline prices combined with compact urban form can result in savings in both residential and transport energy use. In contrast, for developing-country cities with emerging or nascent infrastructures, compact urban form, and transport planning can encourage higher population densities and subsequently avoid lock-in of high carbon emission patterns for travel. The results underscore a significant potential urbanization wedge for reducing energy use in rapidly urbanizing Asia, Africa, and the Middle East.