Co-Mapping Vulnerability to Climate Gentrification in the Context of Urban Heat: A Participatory Index at the Metropolitan Scale

Background: Climate adaptation strategies in cities increasingly risk reinforcing housing inequalities through climate gentrification, that is, the displacement of vulnerable residents driven by both climate impacts and adaptation measures that raise the desirability and cost of resilient, cooler neighbourhoods, thus attracting wealthier residents and real estate investment. While existing research has focused on retrospective patterns of climate gentrification, there remains a need for predictive, participatory tools that inform equitable planning. Methods: This study develops a vulnerability index to climate gentrification focused on heat at the metropolitan scale by using a participatory mixed-methods approach. The index, grounded in the exposure–sensitivity–adaptive capacity framework, integrates spatial indicators with expert knowledge from municipal practitioners and grassroots organizations in the Barcelona metropolitan area. A composite spatial index was created using both equal and expert-derived weights and applied to 2051 census tracts. Results: Findings reveal spatial disparities in vulnerability to climate gentrification across the metropolitan region, with high vulnerability concentrated in peripheral municipalities combining high exposure, social sensitivity, and low adaptive capacity. Expert weighting surfaced divergent perspectives between administrative practitioners—who emphasized infrastructural solutions—and community groups—who highlighted structural inequality and displacement risks. Conclusion: This study offers a novel methodological tool for anticipating displacement linked to climate and urban heat adaptation, but it also demonstrates the value of participatory mapping in vulnerability assessments. In this way, it underscores the importance of embedding housing justice into climate planning, especially at the metropolitan scale, and calls for cross-sector collaboration to ensure that adaptation policies protect, rather than displace, historically marginalized populations.