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C40 Cities

@c40cities.bsky.social
7.7K followers 207 following 688 posts

A network of city mayors delivering urgent climate solutions. Protecting the people and places we love. 🌳🌍🌆💚 www.c40.org

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C40 Cities @c40cities.bsky.social · 3h
Cities are already feeling the impact of a hotter, more unforgiving climate. From opening public areas 24/7 for people to cool down to creating more shade and green spaces, cities like Paris are finding practical ways to protect residents from extreme heat. @egregoire.bsky.social
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C40 Cities @c40cities.bsky.social · 19h
Listen up 🗣️
A collection of graphics following the viral "If your bestie..." internet trend.

Each image uses retro WordArt headers ("Listen up if your bestie..."), Comic Sans bullet points describing helpful qualities, and colourful standard WordArt reading "that's not your bestie," revealing an environmental subject at the bottom:

"Listen up, if your bestie 
gives you energy, loves sunshine, lowers energy bills"
that's not your bestie, that's a solar panel." alongside a solar panel graphic.Listen up if your bestie...
- makes everything look better
- is super organised
- protects biodiversity

that's not your bestie, that's an urban plannerListen up, if your bestie...
tracks pollution trends
makes data-driven decisions
directs clean-air investments towards disproportionatley affected communities

that's not your bestie
that's an air quality monitorListen up if your bestie
- is really quiet
- keeps people moving
- is cutting toxic pollution

that's not your bestie
that's an electric bus
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C40 Cities @c40cities.bsky.social · 01/10/2026
Over the last 4 years, global emissions rose by 2%. Meanwhile, C40 cities cut emissions per person by 3.5% – proving that cities have the power to drive real change. Dive into the work mayors and cities are putting in every day to protect the people and places we love: bit.ly/C40AnnualReport2025
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Reposted by C40 Cities
Climate Caucus @climatecaucus.bsky.social · 29/09/2026
What if there are reasons to hope for a more #resilient #climate future right here in Canada? The Cities 1.5 podcast new miniseries, Oh Canada, features #elbowsupforclimate signatories who are leading on local climate solutions: buff.ly/RToT2VC @c40cities.bsky.social
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C40 Cities @c40cities.bsky.social · 24/09/2026
36 cities in C40’s Cool Cities Accelerator are helping millions of people stay safe as temperatures rise. Lessons from pilot projects in cities such as New York City and Miami are now being shared across the C40 Cool Cities Accelerator to help these solutions reach more people.
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C40 Cities @c40cities.bsky.social · 24/09/2026
Sessions during Climate Week NYC are looking at how cities can prepare for intensifying heat and unpredictable weather, with US mayors across the country already responding; Phoenix is expanding shade, Austin is making homes cooler, and NYC is improving access to essential cooling for tenants.
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C40 Cities @c40cities.bsky.social · 24/09/2026
Governor of California @gavinnewsom.bsky.social speaking at the United Nations on the power of local climate action.
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C40 Cities @c40cities.bsky.social · 24/09/2026
Mayor of Boston & C40 Vice-Chair @mayorwu.boston.gov speaking at the United Nations on the impact and importance of taking climate action every day.
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C40 Cities @c40cities.bsky.social · 24/09/2026
Mayor of Freetown & C40 Co-Chair Yvonne Aki-Sawyerr speaking at the United Nations on why cities matter in the fight against climate breakdown.
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C40 Cities @c40cities.bsky.social · 23/09/2026
"Before 2023, we only had about 14 days where the heat was over 105°. This August alone, we had 17 days in a row over 105°." - Mayor of Miami Eileen Higgins on the urgent need to act to help people stay safe as temperatures rise.
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C40 Cities @c40cities.bsky.social · 23/09/2026
“Spaces like this provide incredible guidance. We’ve benefited so much from Climate Mayors and C40’s infrastructure.” - Mayor Wu speaks with Eric Garcetti at the @climatemayors.bsky.social Leadership Forum on the benefits of working with other city mayors.
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C40 Cities @c40cities.bsky.social · 23/09/2026
“We need guardrails to protect our residents and their energy costs” - Mayor @justinmbibb.bsky.social on exploring the sustainable, beneficial growth of data centres.
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C40 Cities @c40cities.bsky.social · 23/09/2026
“Data centres can afford to give back to our community. If we all fight for sustainability in our communities then we’re more likely to get a great outcome.” - @mayorgallego.bsky.social.
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C40 Cities @c40cities.bsky.social · 23/09/2026
At @climatemayors.bsky.social Leadership Forum at #ClimateWeekNYC, @mayorgallego.bsky.social of Phoenix and Mayor @justinmbibb.bsky.social of Cleveland discussed energy, data centres, and growing their economies while protecting people from rising costs ⬇️
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C40 Cities @c40cities.bsky.social · 22/09/2026
With Ramboll, our new research shows how cities can expand affordable housing and protect people from climate risks: www.c40knowledgehub.org/s/article/Wh.... @sissemariewe.bsky.social, @annehidalgo.bsky.social & Anacláudia Rossbach examined how cities can deliver on housing in a changing climate.
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C40 Cities @c40cities.bsky.social · 22/09/2026
Mayor of Freetown and C40 Co-Chair, Yvonne Aki-Swayerr, and New York City Chief Climate Officer Louise Yeung joined young leaders, including winners of C40’s Students Reinventing Cities competition. They explored how young people can shape urban planning for more inclusive, climate-resilient cities.
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C40 Cities @c40cities.bsky.social · 22/09/2026
We heard from Simon Stiell, UNFCCC Executive Secretary, at New York Climate Week today. He spoke to the importance of continued climate action in the US and the power of sharing solutions that work.
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C40 Cities @c40cities.bsky.social · 22/09/2026
Mayors, investors and industry leaders explored how cities can plan for the growth of data centres while protecting energy prices, water, and local communities.
The discussion focused on C40’s Global Urban Data Centre Pact, which sets out a vision for a more sustainable, affordable digital future.
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C40 Cities @c40cities.bsky.social · 22/09/2026
Extreme heat is the deadliest climate risk cities face, and mayors are on the frontline of keeping people safe. C40 and @harvardsalata.bsky.social brought together Mayors Yvonne Aki-Sawyerr, @egregoire.bsky.social and Pramono Anung to see how cities can strengthen life-saving early warning systems.
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C40 Cities @c40cities.bsky.social · 22/09/2026
It's #CarFreeDay ✅ 🚲 🚅 🚌🚶‍♀️
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C40 Cities @c40cities.bsky.social · 22/09/2026
With vehicles such as cars, vans, and trucks among the leading sources of air pollution, trips that don't involve a car can help make our air healthier and our streets cleaner and safer.
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C40 Cities @c40cities.bsky.social · 22/09/2026
On Car Free Day, people around the world are encouraged to walk, cycle, take the bus or train.
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C40 Cities @c40cities.bsky.social · 21/09/2026
“When a city succeeds, we know there is potential for all cities to succeed.” - Zohran Mamdani, @mayor.nyc.gov, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
“We are more powerful when we work together. Climate change is borderless and unrelenting. In turn; we must be unrelenting in our response.” - NYC Chief Climate Officer, Louise Yeung, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
“Working together is important; being here at U20, we can learn, benchmark, be inspired. We have all the solutions together.” - Mayor of The Hague, Jan Van Zanen, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
“Climate action must benefit people in ways that they can see and feel in their daily lives. Jakarta is ready to serve what works, learn from other cities and turn the climate issues into practical solutions” - Governor of Jakarta, Pramono Anung, at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
“We have a lot to do to face these challenges, and I’m sure the U20 will help us to succeed.” - Mayor of Paris @egregoire.bsky.social, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
“We need to work side-by-side because whether it’s our neighbour across the street or across the ocean, this problem is our problem and the only viable solution is the one we developed and delivered together.” - Julia Kerson, NYC deputy mayor for operations, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
“We need to work side-by-side because whether it’s our neighbour across the street or across the ocean, this problem is our problem and the only viable solution is the one we developed and delivered together.” - Julia Kerson, NYC deputy mayor for operations, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 21/09/2026
Climate Week NYC is here! 🇺🇸 🗽 💚 With city leadership more vital than ever, mayors are coming together at #ClimateWeekNYC to collaborate and share ideas on how to protect the people and places we love.
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C40 Cities @c40cities.bsky.social · 21/09/2026
“We believe that we must march boldly into the future or we risk being dragged into it backwards. It calls for rigorous international collaboration.” - Elle Bisgaard-Church, Chief of Staff to @mayor.nyc.gov, speaking at U20. 📷: Scout Tufankjian
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C40 Cities @c40cities.bsky.social · 20/09/2026
“We believe that cities have many of the answers.” - @zohrankmamdani.bsky.social @mayor.nyc.gov at U20.
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C40 Cities @c40cities.bsky.social · 20/09/2026
C40 Co-Chair and Mayor of Freetown, Yvonne Aki-Sawyerr is sharing the work of fellow C40 mayors at U20 and highlighting where greater co-operation can help cities go further.
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C40 Cities @c40cities.bsky.social · 20/09/2026
Nearly 1 billion people live in C40 cities, and over 30 of those cities have come together for this year’s Urban 20 (U20). Co-hosted by Los Angeles and New York, the summit will see mayors identifying shared priorities and opportunities for action on some of the world’s most pressing challenges.
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C40 Cities @c40cities.bsky.social · 19/09/2026
⭐ U20 is here ⭐ At Urban20, mayors are discussing measures cities are already taking to build more affordable housing, protect tenants and make homes and neighbourhoods more resilient.
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C40 Cities @c40cities.bsky.social · 18/09/2026
“Our cities are choosing cooperation.” - @mayor.nyc.gov, Zohran Mamdani Over the next two days, over 30 cities will come together for this year’s U20, co-hosted by Los Angeles and New York, to identify opportunities to act on some of the world’s most pressing challenges.
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C40 Cities @c40cities.bsky.social · 09/09/2026
While El Niño itself is a natural process, the rapid rate at which the planet is heating is anything but natural. No city faces El Niño alone. Our cities are working together to share knowledge, data, and solutions to prepare for a more extreme climate.
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C40 Cities @c40cities.bsky.social · 09/09/2026
It occurs every 2-7 years and can disrupt weather around the world - bringing more heat, drought, rain and flooding.
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C40 Cities @c40cities.bsky.social · 09/09/2026
What is El Niño? El Niño is a natural climate pattern that starts in the tropical Pacific.
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C40 Cities @c40cities.bsky.social · 08/09/2026
"How do you protect millions of people when extreme heat is no longer an exceptional event, but an increasingly familiar part of summer?" The mayors of Milan, Paris, and Phoenix answer how cities are sharing strategies and taking action in @theguardian.com: www.theguardian.com/commentisfre...
theguardian.com
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C40 Cities @c40cities.bsky.social · 05/09/2026
The future of the Amazon is being shaped in its cities. The Amazon is home to millions of people. We’re working with 11 Amazonian cities to strengthen climate action - from cleaner mobility to better waste management.
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C40 Cities @c40cities.bsky.social · 03/09/2026
How can cities ensure everyone has safe, affordable housing without putting unsustainable pressure on the planet? The Journal of City Climate Policy and Economy is seeking research and policy guidelines for our Dec 2027 housing issue. Deadline for abstracts is 30 Oct 2026: c40.me/4yidYRd
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C40 Cities @c40cities.bsky.social · 03/09/2026
Catastrophic floods, dangerous heatwaves, deadly wildfires. This year, the world has seen extreme weather that has affected millions of people, claimed lives and devastated communities. The climate crisis is already here. We can't deny it. We must act.
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C40 Cities @c40cities.bsky.social · 20/08/2026
How can cities keep critical services running during conflict and ensure communities remain protected? In this episode of Cities 1.5, host David Miller and Oleksandyr Senkevych, Mayor of Mykolaiv, discuss decentralising energy, using real-time data, and building resilience: lnk.to/HotTakes6
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C40 Cities @c40cities.bsky.social · 19/08/2026
Kinda chic to breathe clean air ⬇️
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C40 Cities @c40cities.bsky.social · 13/08/2026
🇬🇧 In London, young people are shaping the city's plans to deal with extreme heat. 🇬🇷 In Athens, young people are co-designing local climate plans.
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C40 Cities @c40cities.bsky.social · 13/08/2026
🇲🇾 In Kuala Lumpur, young people are building apps to fight the climate crisis. 🇸🇱 In Freetown, young people are planting and caring for trees, leading local climate projects, and helping protect communities from heat and flooding.
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C40 Cities @c40cities.bsky.social · 13/08/2026
🇧🇷 In São Paulo, young people are transforming streets with rain gardens, parks, and green spaces. 🇮🇳 In Vadodara, young people are helping create a city resilience plan that aims to restore green spaces.
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C40 Cities @c40cities.bsky.social · 13/08/2026
Young people are helping make cities greener, cooler, and more resilient. This #YouthDay, learn how C40 cities around the world are bringing the voices of youth into climate planning.
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C40 Cities @c40cities.bsky.social · 13/08/2026
Q: How to build a climate-resilient city? A: Include young people. #YouthDay2026
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