Learning about urban climate solutions from case studies


Climate mitigation research puts increasing emphasis on cities, but much more could be learned from urban case studies. The overall size, geographic scope and topic content of cases remains unknown, resulting in few attempts to synthesise the bottom-up evidence. Here, we use scientometric and machine-learning methods to produce a comprehensive map of the literature. Our database of approximately 4,000 case studies provides a wealth of evidence to search, compare and review. We find that cities in world regions with the highest future mitigation relevance are systematically underrepresented. A map of the evidence allows case studies to be matched with urban typologies in new and more ambitious forms of synthesis, bringing together traditionally separate strands of qualitative and quantitative urban research.

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Fig. 1: Number of urban climate mitigation case studies, grouped according to city size.
Fig. 2: Size bias in urban mitigation case study research.
Fig. 3: Global coverage of urban case studies.
Fig. 4: Number of mitigation studies by city and topic.
Fig. 5: Bringing together case study evidence and typologies.

Data availability

The full list of case studies is provided in Supplementary Dataset 1.


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M.W.C. acknowledges financial support from the Heinrich Böll Foundation.

Author information




W.F.L., F.C. and J.C.M. designed the research. W.F.L. and M.W.C. performed the analysis. W.F.L. wrote the manuscript with contributions from all authors.

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Correspondence to William F. Lamb.

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Journal peer review information: Nature Climate Change thanks Brenna Walsh and other anonymous reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figures 1–7, Supplementary Tables 1–5 and Supplementary References.

Supplementary Dataset 1

The data sheet contains the full list of case studies, with duplicate entries where more than one city is mentioned in an abstract.

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Lamb, W.F., Creutzig, F., Callaghan, M.W. et al. Learning about urban climate solutions from case studies. Nat. Clim. Chang. 9, 279–287 (2019). https://doi.org/10.1038/s41558-019-0440-x

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