The latest Cool Talks session, “Extreme Heat Action in Cities and Communities,” brought together researchers, city practitioners and implementation partners to discuss passive cooling, community-led housing upgrades and local heat action. The session focused on protecting vulnerable communities from extreme heat without increasing energy demand or emissions.
Ana Paula Pimentel Walker of the University of Michigan said indoor heat remains largely unmeasured, unregulated and overlooked. Research in Brazil and Colombia examined how infrastructure, limited green space and low-cost construction materials can create dangerous indoor conditions, and explored community-led approaches combining thermal modelling, passive cooling retrofits and local knowledge.
Gabriel Harp, also from the University of Michigan, described computer modelling used to compare passive cooling measures before implementation. A Burkina Faso example assessed mud-brick homes with steel and mud-brick roofs, while other options included cross ventilation, second ceilings and solar chimney systems.
In Colombia, Julian Constantino Carvajal presented an ongoing retrofit of a community centre in Luz de Salvación II. The project combines a secondary roof, fiberglass insulation and a thermal coating on the existing metal sheet roof. The settlement has around 430 houses and close to 1,000 residents.
The second panel addressed city-level implementation. UNEP’s Beat the Heat initiative has attracted more than 240 cities and over 100 partners, but early survey findings indicate that almost half of participating cities have not started basic heat mapping or planning. Cities that completed heat mapping or planning were reported to be more than eight times more likely to have begun implementing nature-based cooling solutions.
“Cities are already ranking extreme heat as a top three risk, but at the same time almost half of them have not yet started to do the basic mapping or planning,” said Elsa Lefèvre, Programme Manager for Beat the Heat in UNEP’s Subnational Climate Action Unit.
