When Zohran Mamdani won the NYC mayoral election, many climate advocates breathed a quiet sigh of relief, not because he promised a new direction but because he pledged to carry forward the exact enforcement agenda of his predecessor Eric Adams on Local Law 97, New York City’s landmark building emissions law.

Local Law 97 is the backbone of the city’s decarbonization plan. It sets a carbon emissions threshold for buildings over 25,000 square feet and tightens that threshold every five years, aiming to cut total building emissions 40% by 2030 and 80% by 2050. The city plans to enforce these emissions requirements by fining $268 per metric ton of excess carbon emissions over a building's annual limit, with additional penalties for late or false reporting. But just beneath the optimism of such an ambitious law lies a quiet, growing problem: some of the city’s most heavily fined buildings aren’t glass towers or luxury condos. They’re data centers, and many are hiding in plain sight. 

Buildings like 111 8th Avenue in Chelsea or 32 Sixth Avenue in Tribeca may look like ordinary commercial buildings, but they’re also home to dense clusters of servers and cooling systems that run nonstop, consuming enormous amounts of electricity. According to the city’s own Local Law 84 benchmarking data, these hybrid office-data centers are among the most energy-intensive buildings in New York.

Take 111 8th Avenue, the art deco giant once owned by the Port Authority and now dominated by Google offices and data centers. Based on 2023 energy use, this single building should be facing about $4,642,225 in annual fines for exceeding its carbon emissions cap by almost double under Local Law 97. 32 Sixth Avenue, which houses Digital Realty’s JFK13 facility and CoreSite’s NY1 center, is estimated to draw around $183,264 in annual fines.

Data centers operate differently from nearly any other building type. Their energy usage isn’t tied to occupancy or lighting but to computational demand, the digital backbone of everything from online banking to AI image generation. And while the tech industry often touts efficiency gains, the sheer scale of growth has outpaced them. Globally, data centers already consume nearly 2% of total electricity use, and that number is expected to double by 2030.

These are not outliers. Across Manhattan, buildings like 60 Hudson Street, 325 Hudson Street, and 75 Broad Street serve as major data interconnection points. Inside, thousands of servers rattle around the clock, supported by cooling towers and backup generators. Together, they represent an unseen but massive portion of New York’s electricity load, and a blind spot in its climate strategy.

That’s the uncomfortable reality Mamdani’s administration will inherit. His platform commits to “fulfilling the vision of Local Law 97 through greater enforcement and assistance from the City for middle-income homeowners”. But homeowners aren’t the only problem. The biggest carbon footprints belong to corporate tenants and data centers operating in historic buildings, who might even be able to obtain exemptions for Local Law 97 or delay their reporting due to “good faith efforts”.

There are solutions. The city could carve out clearer guidelines for data center-heavy buildings, setting realistic reduction targets while requiring on-site or community renewable offsets. And beyond enforcement, there’s a political question: should New York continue to serve as a major hub for data infrastructure if the environmental costs are hidden in its skyline? Cities like Amsterdam and Dublin have already paused new data center approvals to protect their grids. New York might not need a moratorium, but it does need a plan that acknowledges the digital economy has a physical footprint.

Local Law 97 was designed to make emissions visible, measurable, and actionable. It can’t succeed if the city’s most powerful tenants are allowed to operate in the shadows. As the new mayor takes office, this is the moment to decide whether New York’s climate law will be remembered as a model for urban decarbonization, or a missed opportunity buried beneath the hum of its servers.