Global initiative aims to protect residents and transform urban spaces to prepare for a hotter future

• Mayor Yvonne Aki-Sawyerr joins 33 city leaders from around the world in supporting UN Secretary-General’s call for action on extreme heat

Rio de Janeiro, Brazil (3 November 2025) – Freetown has today become a founding member of a new global coalition of cities taking urgent, coordinated action to tackle one of the most dangerous impacts of the climate crisis: extreme heat.

By becoming part of the C40 Cities Cool Cities Accelerator, announced today at the World Mayors Summit in Rio de Janeiro, Freetown is committing to protect its residents from escalating heat risks and to transform its urban spaces for a safer, cooler future.

Extreme heat is already the deadliest weather-related hazard worldwide, responsible for an estimated 489,000 deaths annually. Without decisive action, the number of people exposed to life-threatening urban heat is projected to increase fivefold by 2050.

C40 established the Accelerator in partnership with The Rockefeller Foundation and with implementation support from ClimateWorks Foundation and Robert Wood Johnson Foundation.

The Accelerator provides a practical, science-based framework for cities to respond together to this global threat. By joining, Freetown is contributing to an ambitious shared mission: to protect residents and transform urban spaces to prepare for a hotter future.

Through the Accelerator, Freerown will:

• Protect residents by establishing clear heat leadership, strengthening early warning systems, and expanding access to cooling solutions during heat emergencies within two years.
• ⁠Transform the city for the future by updating building codes to keep indoor temperatures safe, increasing shade and tree canopy in public spaces, and future-proofing critical infrastructure within five years.

This Accelerator answers the call to action on extreme heat from the United Nations Secretary-General and supports the COP30 Beat the Heat action agenda, a flagship effort to implement solutions that speed up local responses to extreme heat and promote sustainable cooling for cities together with national governments.

“The C40 Cool Cities Accelerator ensures cross-agency coordination to provide citywide and long-term solutions, to both Protect and Transform. Protecting with immediate and concerted action to save lives today from extreme heat and Transforming our cities by investing in long-term solutions to cool our city through what we build and the materials we use, how we design cooling for transit and at places of work both indoor and outdoor, and how we ensure that our energy, water and other infrastructure are resilient to increasing temperatures,” said Mayor Yvonne Aki-Sawyerr OBE, Mayor of Freetown and C40 Co-Chair.

“Extreme heat is a silent killer and an increasingly urgent global threat,” said Mark Watts, Executive Director of C40 Cities. “The number of days that major capitals experience temperatures above 35°C has increased 54% over the past twenty years. Cities like Freetown are showing real leadership by taking practical steps to protect communities, safeguard economies, and create more liveable urban environments. By aligning with the UN Secretary-General’s call to action on extreme heat, these cities are helping to set a global standard for what bold, collective climate leadership looks like.”

The Cool Cities Accelerator brings together a diverse group of cities representing over 143 million people from every region of the world, including Austin, Boston, Buenos Aires, Freetown, Nairobi, Phoenix, Singapore, Paris and many others (full list available in notes). By sharing strategies and scaling proven solutions, cities can act faster and more effectively than they could alone.

By joining the Cool Cities Accelerator, Freetown is part of a global movement working to save lives, strengthen resilience, and create thriving, heat-resilient cities for generations to come.

ENDS

NOTES TO EDITORS

Media contacts:

John Baimba Sesay-Senior Manager, Communications, C40 Freetown Co-Chair Office jbaimba@c40.org

Richard Main – C40 Cities Head of Global Media
rmain@c40.org & media@c40.org

For more information about the Cool Cities Accelerator, visit
https://www.c40.org/accelerators/cool-cities/

For more information about the C40 World Mayors Summit, visit
https://www.c40.org/events/c40-world-mayors-summit-2025/

FULL LIST OF ACCELERATOR SIGNATORIES
Accra
Ahmedabad
Amsterdam
Athens
Austin
Barcelona
Bengaluru
Boston
Buenos Aires
Chicago
Durban (Ethekwini)
Fortaleza
Freetown
Guadalajara
Karachi
London
Melbourne
Milan
Mumbai
Nairobi
New York City
Paris
Phoenix
Quezon City
Rio de Janeiro
Rome
Salvador
Santiago
Singapore
Tel Aviv – Yafo
Tokyo
Tshwane
Vancouver