Introduction
Heat Chronicles (Cròniques de la Calor by its Catalan name) is a new project that appeals to citizen collaboration to identify, in specific neighbourhoods, the urban public spaces — squares, streets, parks, etc. — most exposed to extreme heat in the metropolitan area of Barcelona, and to propose strategies to mitigate its effects. The study aims to cover a wide variety of neighbourhoods with high vulnerability to extreme heat episodes, and to involve the most affected groups, in a way that is unprecedented worldwide.
During the year 2023, the project was ideated by the research group OpenSystems from Universitat de Barcelona. Three pilots were carried out that allowed to optimize the scientific protocol and confirmed the social relevance of the project. During summer 2024, Heat Chronicles was upscaled to 5 neighbourhoods of Barcelona metropolitan area.
Background
Episodes of extreme heat are becoming more frequent and more intense in cities, where the heat island effect accentuates them. As citizens, we must become more aware of the existence of these periods, be able to identify the most vulnerable spaces to heat in our closest urban environment and create inclusive strategies to mitigate the effects of extreme heat. In addition, the heat does not affect us all equally nor do we experience it in the same way everywhere. For this reason, Heat Chronicles involves diverse groups, in terms of age, profiles and places of residence. Their common denominator is that all groups can suffer from heat in a more extreme way.
Concept Development
This new citizen science project is framed into citizen social science, a concept which has been developed by the OpenSystems research group for more than 10 years. Citizen social science is defined as participatory research co-designed and directly driven by citizen groups sharing a social concern. The neighbourhood and its social concerns are at the centre of the research and all stages of the research are nourished by their knowledge.
In Heat Chronicles, the participants are considered as experts due to their knowledge of the public spaces and to their lived experiences during heat waves. That way, the criteria of the participants is prioritized to decide where the temperature measurements and “heat surveys” will be made.
Research Design
During face-to-face workshops, the participants identify the most relevant places in the public space, according to their criteria and in relation to their uses and the heat. Several "heat walks" are then organized where the temperature in these places is measured, as well as the thermal comfort and perception of the neighbours. Finally, the results are interpreted collectively to diagnose the problem more precisely and propose solutions based on scientific evidence.
Social inclusion
During summer 2024, a total of 52 heat walks have been performed, in which 481 persons have participated. The groups of participants stopped in 210 public spaces, where they scored their thermal sensation and comfort.
To be able to engage the neighbours most affected by extreme heat, the project was carried out with the collaboration of thirteen entities, such as public libraries, athenaeums, educational centres, neighbourhood groups and NGOs. Five neighbourhood were investigated: Congrés i els Indians and Sant Pere, Santa Caterina and La Ribera, in Barcelona; the neighbourhoods of Collblanc and Torrassa, in L'Hospitalet de Llobregat, and the municipalities of Sant Vicenç dels Horts and Montcada i Reixac. These neighbourhood were chosen because of their known vulnerability to extreme heat, that could be assessed through a high vulnerability to climate change index, a high population density and a low average income, among others socioeconomic factors.
The different groups involved included elderly people, such as self-organized groups of women, parents of 0-3 years old kids or youth in an especially difficult situation because of school drop off or family distress.
Conclusions
Heat Chronicles demonstrated the feasibility of performing an upscaled citizen science project on urban heat, while keeping the focus on neighbours’ perception and lived experiences.
The first results are being currently discussed with the participants, but the first important learning is that thermal comfort is correlated with the gender and the age range of the participants, while structural urban factors like sky view factor also play a role. These outcomes advocate in favour of considering the diversity of the neighbours’ needs and perceptions, and especially the ones of the most affected neighbours, while designing a resilient city able to mitigate climate change.