53,000 Studies, One Message: Climate Action Must Catch Up with Fast-Growing Cities
World’s largest urban climate study reveals a critical blind spot: rapidly growing cities are underrepresented in research, undermining global climate efforts.
A major new study published in Nature Cities presents the first-ever systematic global stocktake of urban climate change research, identifying over 53,000 relevant scientific publications. The study, led by Simon Montfort (EPFL and University of Bern) and co-authored by Bennett Institute’s Felix Creutzig, lead author of the upcoming IPCC Special Report on Cities. It highlights a fundamental imbalance in where urban climate science is focused—and where it is not.
Using supervised and unsupervised machine learning techniques, the research team developed a searchable, continuously updatable evidence base of urban climate studies. Among the key findings is that fast-growing and often smaller cities, especially in Africa and Asia, are significantly underrepresented in the literature. Of the nearly 20,000 spatially specific city case studies identified, only a small fraction address these rapidly urbanising areas, despite their critical importance for both climate mitigation and adaptation.
“This is a major blind spot,” said Felix Creutzig. “These cities are where the bulk of future emissions and climate vulnerabilities will be concentrated. Yet they’re essentially missing from our global knowledge base.”
The study reveals that 92% of African cities are covered by one or fewer case studies. Across much of South and Southeast Asia, the coverage is similarly sparse. In contrast, cities in Europe, North America, and Oceania—many of which have slower growth rates and already well-established infrastructures—are far more frequently studied. The per capita research coverage in the Global North is roughly double that of the Global South.
The authors argue that this skew may be rooted in academic geography. Researchers are more likely to study cities they live in or are institutionally connected to, and many rapidly growing cities still lack local research universities or access to global research networks. As Creutzig put it, “Academia knows New York, Berlin, and London—but it does not know Kisumu, Khulna, or Kandahar.”
The implications are serious. Without better representation of smaller and fast-growing cities, global science assessments such as those by the IPCC (Intergovernmental Panel on Climate Change) risk being based on biased evidence. The study finds that only 4.6% of the available literature on urban climate change was cited in the IPCC’s Sixth Assessment Report (AR6), with strong preferences for large, well-documented cities and generic cross-sectoral topics. Reviews, which are particularly influential in such assessments, covered only about 12% of the total available case study evidence.
Despite a rapidly growing literature—84% of which has emerged since 2012—research remains fragmented and uneven. Technology-focused and sector-specific solutions such as smart energy grids, radiative cooling, or efficient public transport systems are underrepresented in assessments, despite showing promising climate benefits in the wider literature.
To address these issues, the authors call for three major changes: better synthesis of existing case studies, especially those relevant to adaptation and mitigation in the Global South; the creation of city typologies to facilitate cross-city learning; and targeted efforts to fill geographic data gaps, particularly in small cities with high growth rates and climate risks. This also follows a recent call by Creutzig and colleagues, also published in Nature Cities, asking for better evidence assessments on cities and climate change.
“Closing these gaps is not just a scientific challenge—it’s a policy necessity,” said Creutzig. “Cities are the front lines of climate action. We need to understand what works, where, and why.”
The study provides a powerful new tool for doing so: a living, interactive evidence map that can help researchers, policymakers, and city planners access relevant knowledge more easily. This resource, available at background resources, includes city-specific and general urban climate studies, enabling more systematic and transparent evidence assessments in support of the upcoming IPCC Special Report on Cities.
The full dataset and code are available on Harvard Dataverse at https://doi.org/10.7910/DVN/RSJF0Y. The authors emphasize that the global research community must now work together to fill the gaps that have been quantified so clearly.
Read the full paper
This article is a summary of a research paper:
Systematic Global Stocktake of over 50,000 Urban Climate Change Studies. Nature Cities.
Authors: Montfort, S., Callaghan, M., Creutzig, F. et al.
