- 49 global cities representing over 110 million people now back the Global Urban Data Centres Pact
- C40 brings finance, city and community leaders together to cooperate on responsible AI and digital infrastructure
- US mayors are leading the push for data centres that work for people and planet, with 22 US cities endorsing the Pact.
- GRESB, Climate Bonds Initiative and NAACP Center for Environmental and Climate Justice are latest groups to support C40 mayors’ principles for what good data centres should look like
- Phoenix Mayor Kate Gallego says that C40 Pact “creates greater certainty” for investors, developers and communities
New York, USA (22 September 2026) – Cities are spearheading a global push to ensure the next generation of data centres is cleaner, more efficient, and delivers benefits for the communities that host them.
As political leaders and policy makers, mayors are integral to data centre development. As New York Climate Week gets into full swing, C40 mayors are urging industry to support the Global Urban Data Centre Pact to ensure certainty, sustainability and local community benefits in AI and digital infrastructure investment and construction.
This New York Climate Week C40’s mayors are bringing together finance experts and business leaders to discuss the Pact’s call for sustainable AI and digital infrastructure development in cities. The dialogue comes as public concern over the rapid expansion of data centres and their impact on communities and natural resources grows across the world
US cities now make up nearly half the endorsers (22 out of 49 cities) of the Global Urban Data Centres Pact, a mayor-led initiative, co-founded by Mayor Kate Gallego of Phoenix and Melbourne’s Lord Mayor Nick Reece, that sets out clear expectations for responsible data centre development.
Whilst the US is experiencing a period of concentrated data centre growth, the Pact has been endorsed by cities on every continent, representing more than 110 million people. All signatories agree that it is time to move beyond data centres that threaten to spike energy costs, increase emissions and pollution, create health and safety risks for residents, and use critical water resources.
Climate Mayors and America Is All In support these efforts as organizational partners, and wider official support for the Pact has also come from GRESB, Climate Bonds Initiative and NAACP Center for Environmental and Climate Justice.
New developments must be designed around the needs of the communities that host them. This means protecting water supplies, avoiding unnecessary pressure on energy bills and power grids, using resources efficiently and delivering tangible local benefits.
The Pact, launched at London Climate Action Week in June, recognizes that mayors and city leaders, as those closest to residents’ concerns, must be empowered to act on a cleaner future for this essential infrastructure. The Pact brings together approaches already being pioneered by cities and sets four principles for future developments. These are that data centres should be:
- strategically integrated into cities;
- sustainable and resource efficient;
- developed with and for local communities;
- focused on driving down residents’ costs and delivering shared prosperity
That challenge is particularly urgent in the US, where opposition to new data centres is growing. Recent polling highlights that 79% of Americans are either skeptical or critical of data centres. Yet, if clean energy is integrated into data centres, net support increases from -33% to +16%. The rapid growth and low regulation of the industry has led some local governments to instigate temporary moratoriums while they decide how further development should proceed.
The principles of the Pact allow cities to agree with developers and investors on what a responsible and sustainable future looks like.
Clear standards can also provide greater certainty for investors. Setting expectations early can help capital flow towards sustainable projects that are more likely to get approved by cities, rather than dirty data centres that do not align with the Pact.
US mayors and city leaders met with investors, lenders and industry representatives in New York this week to discuss how the financial community can help deliver the next generation of digital infrastructure and leverage principles for long-term sustainability to build community trust and reduce exposure to material risks.
The meeting, co-hosted by C40 Cities and sustainable benchmarking organisation GRESB, brought together US cities, real asset investors, mission-driven investors, asset managers, commercial lenders and developers to discuss approaches to identify, mitigate, and finance solutions to the socio-environmental risks of data centre expansion, and make sure data centres generate shared value for both local communities and shareholders.
Kate Gallego, Mayor of Phoenix and C40 Cities Vice Chair, said: “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.
“Phoenix has seen first-hand the opportunities that come with investment in clean technology, advanced manufacturing, and 21st century infrastructure, but growth has to be managed responsibly. Our residents expect infrastructure to keep pace, health and safety to be prioritized, resources to be used wisely, and local communities to share in the benefits.
“The Pact offers a clear framework for collaboration among cities, investors and industry. By setting expectations now, we can create greater certainty for responsible investment and support innovation that strengthens our economies and improves quality of life.”
Brandon Johnson, Mayor of Chicago, said: “As data centers continue to expand across the country, mayors have both an opportunity and a responsibility to shape the growth of the industry and ensure new infrastructure is developed responsibly, transparently and safely.
“Establishing clear standards on critical issues, from air quality to energy use, will give industry the clarity it needs to plan and invest responsibly while giving communities confidence that new development will protect their well-being and deliver meaningful benefits.
“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 center 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.”
Kate Johnson, C40 Cities Director for North America, said: “Mayors are showing global leadership on one of the defining infrastructure challenges of the AI age. They recognize the potential economic benefits of data centers, but they also know that dirty, inefficient developments which damage communities cannot be the future.
“But instead of closing the door on data centers, they’re raising the bar. Where cities have paused development, now is the moment for mayors, investors and industry to agree on the rules that allow the right projects to go ahead but only if they work for communities and the planet.
“When those pauses end, we want investment flowing into cleaner, more efficient data centers that communities can support. The Pact gives cities and investors a practical blueprint for making that happen.”
Chris Pyke, Ph.D., Director, Thought Leadership & Industry Engagement, Global Real Estate Sustainability Benchmark (GRESB), said: “GRESB recognizes the vital role cities play in setting a high bar for data center development. We share the goals of the C40 Global Data Center Pact, including sustainable and resource-efficient data centers that deliver tangible benefits for local communities.
“GRESB’s new Data Center Assessment supports these aspirations with a common language providing transparency and comparability, and, ultimately, building trust among financial stakeholders.”
Sean Kidney, CEO, Climate Bonds Initiative, said: “Cities are on the frontline of the data center boom, from hosting the infrastructure, managing the grid pressure, and bearing the community impacts.
“Climate Bonds Initiative supports the C40 Urban Data Centers Pact because sustainable data center development is not just an engineering challenge; it is a finance challenge.
“Getting the criteria right is how we ensure the capital flowing into this sector drives genuine climate action rather than greenwashing. We are proud to support this initiative and the ambition it represents”.
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Cities are shaping the future of the digital infrastructure that powers our digital lives, ensuring data centres are sustainable and benefit local communities.
Find out more about C40’s announcements and activities at the United Nations General Assembly and Climate Week NYC, taking place in New York City from 20-27 September 2026
Supporting cities to create ambitious climate strategies that deliver meaningful community benefits.
