Seventeen city types define distinct pathways for climate mitigation and adaptation worldwide

Felix Creutzig, Alona Zharova, Florian Nachtigall, Simon Montfort

 Understanding that cities are main arenas of climate action, it remains unclear 
which cities should focus on what kind of action taking a global comparative lens. Recent 
contributions identified four different types of cities across seven world regions, while others 
specified a huge case study literature database on cities and climate change biased towards 
established, stagnant, and megacities, largely ignoring smaller, rapidly growing cities, mostly 
in the Global South. Here, we comprehensively assess climate risks and related motivations 
to act, climate solutions, and their main co-benefits and feasibility challenges for 17 types of 
cities. For this, we rely on three different data modalities: a) a global database of >10000 
cities and 16 different quantitative characteristics; b) AI assisted full-text analysis of >1200 
scientific papers on representative cities of 17 different types; and c) AI-assisted web-based 
evidence synthesis for representative cities and their challenges. While the first two steps 
enable evidence identification with medium to high confidence, the third step allows to fill 
crucial gaps and debias the analysis, albeit subject to lower confidence insights. We find that 
smaller and poorer cities in Africa and Asia are strongly motivated to develop WASH 
infrastructure, that rapidly growing and megacities will need to focus on future proof urban 
planning, and that established cities, mostly in Europe, North America and East Asia, but 
also cities in small island states aim to disentangle from costly gas and oil dependence in 
heating and transport sectors. Cities that aim for net-zero are co-motivated by a high quality 
of life.