Living in unbearably hot cities – is this our future?

Climate change and its impacts, such as extreme heat, represent an unprecedented challenge for cities, causing overheating and threatening the future prosperity, health and well-being of urban residents. Climate adaptation is one of the central topics for sustainable cities and societies. Yet, we have limited knowledge about the magnitude of climate change that we will face in the future, and we don’t know how, where and when should we adapt to these changes.

In the project Urban Adaptation Challenges: Promoting Sustainable Planning Using Integrated Vulnerability Analysis, funded by the Technology Agency of the Czech Republic, our research collective has looked into uncertainties driven by climate change and what are the emergent impacts on cities. Together with the largest and most populated Czech cities – Prague, Brno and Ostrava – we have developed and tested a methodological approach to assess changes in urban vulnerability to extreme heat until 2050. 

The assessments show to what extent the particular urban zones will become vulnerable or resilient to high temperatures under the different future human development pathways (Shared Socioeconomic Pathways, SSPs) and the correspondent levels of greenhouse gas emissions (Representative Concentration Pathways, RCPs) that have direct implications on the magnitude of climate change. We downscaled these global pathways based on regional climatic and demographic prospects, and land use plans of involved cities to best represent reality at an urban scale. These data sources fed into modelling future urban development, land use and land cover changes, for the sustainability scenario and the middle of the road scenario, and were calculated for the three variants of adaptation measures to mitigate vulnerability – low, medium and high adaptation. Finally, we produced several sets of spatially-explicit models interpreting changes in future urban vulnerability to extreme heat under different prospects (by 2050).

Resulting models suggest that future global greenhouse emission levels (RCPs), extent of sealed urban area and urbanisation patterns, and population distribution and density have direct implications on urban vulnerability. Another important point is that extensive implementation of adaptation measures can substantially reduce vulnerability.

In practical terms, the vulnerability assessments help us recognise the urban neighbourhoods and blocks prone to climate hazards. Further, it helps us understand how the vulnerability will change under different future scenarios. Such information has great value and importance for strategic adaptation planning, to set adaption priorities and implement appropriate actions in vulnerable areas, as well as to foresee future changes in vulnerability and the resulting adaptation needs. Cities can act today to mainstream adaptation standards in urban planning and, by doing so, minimise future risks emerging from climate change.

We are keen to disseminate science not only in strictly scientific journals but also in periodics with outreach to a broader expert and professional community. We are convinced this could hold a much greater impact than mere scientometrics. You can find more reading about the topic in the article Zranitelnost Vůči Teplotním Extrémům: Čeká Nás Život V Rozpáleném Městě? which is to be published in the upcoming special issue of the journal Urbanismus a Územní Rozvoj with the focus on challenges for urban development (volume 5/2022).

This blog post builds on work of authors: Simeon Vaňo, Petr Bašta, Lenka Suchá, Jan Geletič, Martin Jančovič, Helena Duchková.