Transforming the way we plan cities to cut emissions and build resilience
Through shared commitment, cities are replacing sprawl with compact, connected development
The dominant urban planning model of the 20th century, characterised by sprawl, car-oriented development, and rigid land-use zoning, has made cities highly emissions-intensive and negatively impacts the health and quality of life of many residents. Over the next 30 years, an additional 2.4 billion people will live in urban areas, bringing the global urban population to 66%.[1] Rapid population growth, combined with unplanned urban expansion, has significantly increased cities’ vulnerability to climate hazards and increased emissions.
Urban planning is one of the most powerful tools for climate action. Through spatial plans, policies, legislation, building codes, and municipal by-laws, urban planning sets the blueprint for how cities grow and evolve. The IPCC reports that more compact land use could cut emissions by up to 25% by 2050.[2]
The C40 Urban Planning Accelerator, created in partnership with UN-Habitat, unites cities to fast-track climate-responsive planning that prioritises people, the planet, and shared prosperity. By adopting this approach, mayors are committing to building cities that cut emissions, protect communities from climate risks, restore ecosystems, and are vibrant, inclusive places where everyone can thrive.
Why cities are choosing climate-responsive planning
Mayors are reimagining urban development because climate-responsive planning delivers better outcomes for people, planet, and prosperity.
Cutting emissions at the source
Preventing carbon lock-in through smart growth and regeneration
The physical layout of cities determines transportation needs, energy use, and emissions for generations. Compact, mixed-use development near transit dramatically reduces the need for car travel and cuts building energy demand. The choices planners make today will determine whether cities can meet future climate targets.
Protecting communities from climate hazards
Building resilience through risk-informed decisions
In many places, risky growth (development in areas prone to floods, landslides, or extreme heat) is outpacing safe growth, especially in the Global South, where 90% of urban expansion is taking place near hazard-prone areas.[3] Climate-responsive planning restricts development in high-risk zones, secures land for nature to buffer extreme weather, and prioritises resilience for the most vulnerable communities.
Ensuring everyone lives close to essential services and amenities
Bringing opportunity within reach
Development centred around multiple hubs with mixed-use neighbourhoods puts jobs, services, transit, and green space within easy reach of all residents. This matters most for communities that have been historically pushed to city peripheries with limited access to opportunities. Climate-responsive planning creates 15-minute neighbourhoods where everyone can thrive.
Restoring urban ecosystems
Reversing decades of nature loss
Between 1990 and 2020, the area of green spaces in and around cities decreased by 28.7%.[4] Nature-positive planning secures and protects land for ecosystems that cool cities, manage stormwater, and provide community benefits. This represents a fundamental shift, halting destructive sprawl to begin the essential work of restoring our urban ecosystems.
What cities pledge through the C40 and UN-Habitat Urban Planning Accelerator by 2035
Cities that join the C40 and UN-Habitat Urban Planning Accelerator commit to adopting a climate-responsive urban planning model by 2035. This approach transforms how cities grow by reducing emissions through smart development patterns and reducing climate vulnerability through risk-informed, nature-positive, and inclusive planning. Within 10 years, cities commit to incorporating the following objectives into their master plan and/or other relevant land-use plans:
Reducing emissions through compact, polycentric, and connected development
Compact: Prioritise regeneration and densification over urban sprawl.
Polycentric: Adopt a polycentric model by creating multiple mixed-use centres that bring homes, jobs, and services together.
Connected: Steer new development near transit hubs to encourage sustainable mobility patterns.
Reducing climate vulnerability through risk-informed, nature-positive, and inclusive planning
Risk-informed: Restrict new development in areas of high climate risk.
Nature-positive: Secure and protect land for nature to shield against extreme weather events.
Inclusive: Mandate adequate and affordable housing to improve resilience for the most vulnerable.
Cities committed to the C40 and UN-Habitat Urban Planning Accelerator
Accra, Cape Town, Dar es Salaam, eThekwini/Durban, Freetown, Johannesburg, Tshwane, Quezon City, Tokyo, Athens, Barcelona, Copenhagen, Istanbul, Madrid, Milan, Paris, Bogotá, Buenos Aires, Curitiba, Fortaleza, Guadalajara, Lima, Medellín, Quito, Rio de Janeiro, Chicago, Portland, Vancouver, Amman, Karachi
How cities will deliver these commitments:
Cities will incorporate six climate-responsive objectives into their master plans and relevant land-use plans by 2035. These objectives work together to reduce emissions through compact, polycentric, and connected development, while reducing climate vulnerability through risk-informed, nature-positive, and inclusive planning. Cities will prioritise regeneration over sprawl, foster mixed-use neighbourhoods near transit, restrict development in high-risk areas, secure land for nature, and mandate adequate affordable housing to improve resilience for the most vulnerable.
Joining the C40 & UN-Habitat Urban Planning Accelerator is a significant step for Accra as we work to build a resilient, inclusive, and sustainable city. This partnership will enhance our capacity to integrate climate action into urban development, improve infrastructure planning, and ensure that growth benefits all residents. Through collaboration and innovation, we aim to position Accra as a model for climate-smart urban transformation across Africa
Hon. Michael Kpakpo Allotey, Mayor of Accra
Copenhagen is proud to have joined the Urban Planning Accelerator. Urban development and climate action have gone hand in hand for many years in Copenhagen. Over the years, we’ve gained valuable experience in creating a resilient, liveable, and climate-friendly city — with flood-adaptive and green neighborhoods and a strong focus on carbon-neutral mobility. Through the Accelerator, we look forward to sharing our lessons and learning from other cities committed to the same path. Together, we can advance climate-responsive urban planning and demonstrate that ambitious climate goals can flourish alongside vibrant urban life, and socially balanced development.
Lars Weiss, Lord Mayor of Copenhagen
A greener and more resilient Quito is the city we are building for future generations. By joining the C40 & UN-Habitat Urban Planning Accelerator, we are transforming our vision into commitment and concrete actions: a compact, polycentric, and connected city that reduces emissions and brings services closer to every neighborhood; a preventative, inclusive, and nature-based model that strengthens our resilience to climate risks. We prioritise mixed-use neighborhoods, sustainable mobility, and the protection of our ecosystems. This commitment strengthens compliance with our Climate Change Action Plan and commits us to planning with the well-being of all Quito families in mind. Every decision today builds a safer, healthier, and more livable capital for all.
Pabel Muñoz, Mayor of Quito
Questions about the C40 and UN-Habitat Urban Planning Accelerator?
Cities interested in signing onto the Accelerator or learning more can contact the C40 Urban Planning and Design team at upd@c40.org.
Related
The Jameel C40 Urban Planning Climate Labs aid cities in incorporating climate action plans throughout all municipal functions, serving as a driving force for ambitious and deliverable climate action.
Urban planning measures are critical for cities to be able to deliver on their greenhouse gas emissions reduction targets and reduce their vulnerability to climate hazards. C40’s Urban Planning work supports cities to develop, implement and share planning strategies and regulations that set a framework for sustainable and equitable urban growth.
Discover how mayors and cities worldwide are delivering on their commitments to take urgent climate action through C40’s High-Impact Accelerators.
Sources
- [1] (UNEP, 2018)
- [2] (IPCC report, 2022).
- [3] (World Bank, 2020. Building Sustainable Cities and Communities)
- [4] (UN-Habitat, 2024. Cities and Climate Action: World Cities Report 2024)