From Low- to Net-Zero Carbon Cities: The Next Global Agenda

• Published in: Annual review of environment and resources 2021-01, Vol.46 (1), p.377-415
• Main Authors: Seto, Karen C, Churkina, Galina, Hsu, Angel, Keller, Meredith, Newman, Peter W.G, Qin, Bo, Ramaswami, Anu
• Format: Article
• Language: English
• Subjects: carbon-free city; carbon-neutral city; climate-neutral city; deep decarbonization; net-zero cities; zero-carbon city
• ISSN: 1543-5938; 1545-2050
• DOI: 10.1146/annurev-environ-050120-113117

This article provides a systematic review of the literature on net-zero carbon cities, their objectives and key features, current efforts, and performance. We discuss how net-zero differs from low-carbon cities, how different visions of a net-zero carbon city relate to urban greenhouse gas accounting, deep decarbonization pathways and their application to cities and urban infrastructure systems, net-zero carbon cities in theory versus practice, lessons learned from net-zero carbon city plans and implementation, and opportunities and challenges in transitioning toward net-zero carbon cities across both sectors and various spatial fabrics within cities. We conclude that it is possible for cities to get to or near net-zero carbon, but this requires systemictransformation. Crucially, a city cannot achieve net-zero by focusing only on reducing emissions within its administrative boundaries. Cities must decarbonize key transboundary supply chains and use urban and regional landscapes to sequester carbon from the atmosphere. Because of carbon lock-in, and the complex interplay between urban infrastructure and behavior, strategic sequencing of mitigation action is essential for cities to achieve net-zero.