Phoenix mayor joins 40 city leaders worldwide in pact to set rules for data center growth

Phoenix Mayor Kate Gallego has joined 39 other mayors from around the world in signing a new pact aimed at shaping how data centers are built and operated in cities.

C40 Cities, an alliance of nearly a hundred cities seeking to impact climate change, launched the pact Tuesday during London Climate Action Week.

Under the pact, data centers should not rely on fossil fuels for on-site power and should bring new renewable energy generation or battery storage online to match their electricity consumption, reducing pressure on local grids rather than adding to it.

Gallego said she’s concerned that investments in data centers right now are worsening climate change and not benefitting communities.

“We understand the importance of this innovation, it’s creating great jobs in our community,” Gallego said. “We just want to make sure that we get it right for our local residents and for the health of our planet.”

Data centers are here

Todd Thomas, founder and CEO of Woodchuck, a Scottsdale-based renewable energy company that works with data center construction projects, said the pact takes the right approach.

“Let’s look at this strategically as a city,” Thomas told KTAR News 92.3 FM. “We are going to support AI data centers because we know that’s the future, and we want that investment and we want those jobs in our communities. But let’s balance that into where we put them and how we’re going to power them, and let’s put some requirements around that.”

Phoenix is among the top 10 data center markets in North America, according to industry reports.

The Phoenix metropolitan area has pending permit requests that would double electricity demand if all the proposed data centers were built, reports The Associated Press. Developers are drawn to the area for its reliable power and predictable weather.

C40 got involved because the mayors of Phoenix and Melbourne, Australia, came together over worries about data centers using a lot of their cities’ electricity and water, and competing with housing developers for available land, according to The Associated Press.

Phoenix already established data center guardrails

In July 2025, the Phoenix Mayor and City Council approved updates to the city’s zoning ordinance to add data centers as a permitted use that must address health and safety concerns when applying for a special permit for construction.

About half of participating mayors are from the U.S., with international signatories representing Europe, Africa, Asia and the Middle East.

KTAR News 92.3 FM’s Heidi Hommel and The Associated Press contributed to this report.

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