Forty mayors representing cities across the globe have put their names to a new agreement designed to give local leaders more influence over how data centers are built and run in their communities. The pact was announced Tuesday during London Climate Action Week.
The agreement was organized through C40 Cities, an alliance of nearly 100 municipalities working to address climate change. The group says roughly 1,700 data centers already exist within its network of cities, and that number is expected to grow by more than 40% in 50 of those cities.
While many new data centers are heading to rural areas where land is cheaper, C40 says urban areas are also facing enormous pressure from this rapid expansion.
The effort got its start when the mayors of Phoenix and Melbourne, Australia, came together over shared concerns — specifically that data centers were consuming large amounts of electricity and water while also competing with housing developers for available land.
“We found out that the challenges in every region around the world were very similar,” said Cassie Sutherland, a managing director at C40. “Our approach was to say OK, how do we now use a global mayoral voice to come together with the conditions under which they will accept data centers.”
Data centers tend to cluster in cities because businesses using artificial intelligence need systems that respond instantly, and companies want their data infrastructure close to their operations. Andrew Batson, global head of data center research at JLL, noted that data centers moving into rural areas is a more recent trend.
Public and political pushback against data centers has been building due to concerns about power outages, higher electricity costs, and the massive amounts of water these facilities require. Some states have already paused tax incentives or are weighing construction moratoriums.
Roughly half of the mayors who signed the pact are from the United States. American cities include Seattle, Palo Alto and Riverside in California, Phoenix and Albuquerque in the Southwest, Beverly in Massachusetts, Lincoln in Nebraska, Chicago and Cleveland in the Midwest, and Miami in the South.
International participants include cities in Greece, Spain, Italy, Germany, the United Kingdom, Norway, and Montreal in Canada. African cities from Ivory Coast, Sierra Leone, South Africa, and Kenya also joined, along with Asia-Pacific cities in India and Australia, and Lebanon in the Middle East.
Sutherland said the pact must now be turned into real action, with each city using it as a guide for crafting local regulations or policies. Mayors will need support from other government officials, utility companies, and the private sector to make meaningful changes.
The agreement outlines several key standards: data centers should be built on abandoned or underused land, minimize noise, heat, and air pollution, run on renewable energy and battery storage, cut water use and emissions, and capture waste heat. Mayors also want data centers to create local jobs, purchase goods and services locally, fund their own infrastructure upgrades, and engage with community members.
In the Phoenix area, pending permit requests alone could double electricity demand if all proposed data centers are built. Developers are drawn to the region because of its reliable power supply and consistent weather.
Phoenix Mayor Kate Gallego expressed concern that current data center investments are worsening climate change and failing to serve local residents. She said a united front among mayors will prevent developers from simply seeking out communities that lack the power to negotiate better terms.
“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.”
As of Tuesday, no cities from Southeast Asia had signed the pact. C40 said several cities in that region were unable to join due to national policies or other complications, though discussions are continuing.
Southeast Asia accounts for roughly a quarter of global energy demand growth, driven in part by more than 2,000 data centers operating across Indonesia, Malaysia, Singapore, Thailand, Vietnam, and the Philippines, according to the think tank Ember. The International Energy Agency projects that annual energy demand from those data centers will more than double within five years. Malaysia has been a particular hotspot, drawing major investments from tech giants including Microsoft, Google, and Nvidia.
Melbourne played a central role in shaping the pact. According to the city’s Lord Mayor Nicholas Reece, if Melbourne follows through on all its current plans, data centers there could consume up to 20 billion liters — roughly 5.3 billion gallons — of water annually, equal to about 4% of the city’s drinking water supply. That water supply is already under strain from population growth, longer dry spells, and intensifying heat driven by climate change.
Reece said tighter environmental regulations in Melbourne are unlikely to drive away future investment, noting that data centers ultimately go where there is sufficient power, land, and proximity to markets and companies using artificial intelligence.
“We don’t want to see a race to the bottom between cities where governments, desperate for investment, are chasing data centers on any terms possible,” he said. “We want to see a better framework in place so that the investment rush in data centers can be a win-win — a win for investors and also a win for local communities.”
