Mayors of 40 of the world’s largest cities have agreed to work together to mitigate the growing impact of data center expansion on power supply, water sustainability, and local communities.

The Global Pact for Urban Data Centers was announced at London Climate Action Week and will set standards for low-carbon energy use and the more effective integration of data centers into urban planning. The pact is expected to include London, UK; Phoenix, Arizona; and Melbourne, Australia, among others.

The rules are expected to be adapted to local conditions, with the framework designed to act as a guide for permitting and planning decisions, as well as negotiations with companies and governments.

“Data centers are the biggest thing to hit the energy grid since air conditioning in the 1950s, and ​where the rollout of air conditioning took decades, this is happening in a few short years,” said Melbourne Lord Mayor Nicholas Reece.

The pact will have four key pillars. These include prioritizing brownfield regeneration and adaptive reuse, respecting local communities by avoiding displacement, and being sited in collaboration with local governments to minimize public health burdens; publishing measurable benchmark data on sustainability and public health metrics; meeting energy demand without building new, extending the operation of existing, or reopening decommissioned fossil fuel plants, and ensuring fair cost coverage by directly funding any necessary infrastructure upgrades (energy, water, and network), utilizing fair share pricing tied to sustainability performance.

According to Phoenix Mayor Kate Gallego, the new pact was needed due to the unprecedented demand from the data center sector. Phoenix and its surrounding area have 225 existing or planned data centers, which could nearly double the city’s electricity demand.

London Mayor Sadiq Khan said in a statement that while AI ​and data centers would play “a major role in the future prosperity of cities around the world… residents are right to expect growth to be managed responsibly.”

The pact will be coordinated by C40 Cities, a network of ​nearly 100 of the world’s biggest cities working together on climate action. A full list of cities can be found here.