Catch up on C40’s highlights from New York Climate Week 2026
As New York Climate Week comes to a close, one message stood out above the rest: mayors aren’t waiting for the future. They’re acting now.
Across energy, housing, extreme weather and resilience, city leaders spent the week sharing tangible results and scalable solutions.
Cities are preparing for extreme heat
Extreme heat remains the deadliest climate threat facing 1 billion people living in C40 cities. Throughout the week, city leaders treated heat adaptation as a top priority.
Through the C40 Cool Cities Accelerator, mayors showed how fast-moving local action saves lives:
- Building on a successful pilot, New York City has secured $350,000 to roll out its cooling pop-ups for outdoor workers across all five boroughs in 2026.
- In Miami, Mayor Eileen Higgins is using data from 156 heat sensors to protect high-risk neighbourhoods before extreme heat hits.
Before 2023, we only had about 14 days where the heat was over 105 degrees. This August alone, we had 17 days in a row over 105 degrees.
Mayor of Miami, Eileen Higgins
To turn local action into long-term resilience, C40 and Harvard’s Salata Institute brought together the Mayors of Freetown and Paris, the Governor of Jakarta and experts in health, data, and finance to explore how cities can plan for a hotter future.
Countries with robust early warning systems experience nearly six times fewer disaster-related deaths.
City leaders shared how they’re strengthening these systems to get life-saving information to residents before severe heatwaves hit.
The heat is with us; it’s no longer a distant threat. As mayors, we also need to track the health impacts; the risk is no longer a risk – it’s reality.
C40 Co-Chair and Mayor of Freetown Yvonne, Aki-Sawyerr OBE
US cities are showing what bold urban climate action looks like in real time
Across the United States, city leadership is strengthening clean energy, good jobs and heat adaptation.
Under Mayor Brandon Johnson, Chicago has transitioned its municipal operations to 100% clean energy. In Boston, Mayor Michelle Wu is strengthening the clean energy workforce by rolling out training placements for more than 4,500 jobs.
In Miami, Mayor Eileen Higgins is championing climate solutions expected to create thousands of green jobs, while Mayor of Phoenix, Kate Gallego, is tackling extreme heat and water shortages side by side: planting nearly 30,000 new trees, installing 500 shade structures and advancing water recycling infrastructure.
Building climate-resilient, equitable cities
A new report from C40 Cities and Ramboll, ‘Where Housing Meets Climate’, shows that expanding access to affordable housing and cutting building emissions go hand in hand. The research highlights that cities don’t have to rely on new construction alone. They can retrofit existing buildings, create more homes close to public transport and jobs and lower the cost of city living by addressing energy, transportation and rent together.
At the launch, Copenhagen Lord Mayor Sissel Marie Welling, Global Ambassador for GCoM and former Mayor of Paris Anne Hidalgo and UN-Habitat Executive Director Anaclaudia Rossbach explored how cities can protect residents from rising utility bills and climate risks at the same time.
We cannot delay housing. And we cannot delay climate action. We must deliver both. Teachers, nurses and families need homes they can afford, but the way we build those homes will also shape our climate for decades to come.
Copenhagen Lord Mayor Sissel Marie Welling
Youth leadership also took centre stage. C40 Co-Chair and Mayor of Freetown Yvonne Aki-Sawyerr, Governor of Santiago Claudio Orrego Larraín and New York City Chief Climate Officer Louise Yeung joined young leaders, including winners of C40’s Youth Reinventing Cities competition. The session, hosted by Gensler with support from the Holcim Foundation for Sustainable Construction, explored how youth-led design can shape more inclusive and resilient cities.
It’s our responsibility to ensure that the views of young people are embedded into the decisions we are taking.
C40 Co-Chair and Mayor of Freetown Yvonne, Aki-Sawyerr OBE
Smarter, sustainable urban growth
As demand for infrastructure skyrockets, mayors, investors and industry leaders discussed how cities can manage data centre growth without straining local power grids, water resources or energy affordability. Leaders highlighted C40’s Global Urban Data Centre Pact as a benchmark for responsible growth that doesn’t come at the cost of local communities.
Mayor Kate Gallego, who co-led the call for a Global Urban Data Centre Pact with Melbourne Lord Mayor Nick Reece, shared how cities can meet the growing demand for data centres while protecting local communities and building a cleaner energy future.
US cities are at the forefront of defining the next era of digital growth and urban development. It’s essential that we work to ensure our cities, and our peers around the world, establish a standard for how our residents get the benefits of the AI and digital economy while protecting the communities that make that growth possible.
Mayor of Phoenix, Kate Gallego
The Pact is a vital tool for cities, investors and industry to unite around a shared vision for responsible growth. The City of Chicago is proud to be part of the Pact and to put its principles into action by developing robust regulatory standards for data centre development. Working with partners in industry, finance, academia and government, both locally and globally, we can build a future with clean energy, clean air and shared prosperity.
Mayor of Chicago Brandon Johnson
With food systems generating one-third of global emissions, cities discussed how they could partner with others to create healthier, more sustainable networks. C40’s upcoming research shows how stronger urban-rural partnerships can help cities:
- improve their food security
- support farmers and local economies
- create green jobs
- cut consumption-based emissions.
Local leadership, global impact
At the UN SDG Media Zone, São Paulo’s Camila Assis joined former mayors Eric Garcetti and Anne Hidalgo for a panel hosted by WIRED. They shared how city action on jobs, extreme weather and a fair transition away from fossil fuels could offer a blueprint for national governments.
Mayor Yvonne Aki-Sawyerr also outlined how Freetown is preparing for climate impacts by building resilience to protect communities.
UNFCCC Executive Secretary Simon Stiell reinforced that city leadership remains the driving force behind global climate momentum.
Climate action is not a burden on prosperity. It’s how we secure it for everyone, everywhere.
UNFCCC Executive Secretary Simon Stiell
It was clear throughout the week that local action is keeping climate progress moving. As national governments negotiate, mayors are on the ground delivering cleaner energy, healthier neighbourhoods and resilient infrastructure. By turning ambition into delivery, city leaders are setting the pace for global climate action and proving that a fairer, climate-resilient future is already underway.