A Global Systematic Map and Database of Climate Change Research on Cities

The Intergovernmental Panel on Climate Change (IPCC) agreed to publish a special report (SR) on cities in assessment report (AR) 7 cycle. The SR seeks to summarise the evidence on climate change impacts and the unique adaptation and mitigation options of cities. However, a systematic overview of the literature on cities, and particularly urban case studies, is missing. This article fills this gap. We show that the IPCC better covers topics for which it can build on existing reviews. However, city case studies, which are growing faster than other research on human settlements and climate, remain insufficiently reviewed and synthesized, posing a considerable gap in the overall assessment of the cities and climate change literature. This gap is most pronounced in case studies on climate change mitigation. Hence, the IPCC needs to place considerable emphasis on assessing more than the existing 20,000 case studies as an underpinning of the SR on cities. Using machine learning to map out the topics in this research space, we provide a comprehensive and accessible global research map and database useful for evidence-synthesis research on cities and climate change.