Mayor Bill de Blasio's biggest climate accomplishment was to preside over a set of laws that targeted the city's greatest contributor to greenhouse gas emissions: buildings.
Known as Local Law 97, the regulations were designed to force big office buildings and smaller residential buildings to electrify their heating, cooling, and cooking, so that by the year 2050, they would lower their carbon emissions from 2005 levels by 80 percent.
But since Mayor Eric Adams took office, large office buildings (many owned by contributors to Adams) have been granted extensions and leniency when it comes to getting off of fossil fuels or making environmental upgrades, while large residential co-ops are staring down deadlines to begin energy-saving measures and electric heating conversions that many say they can't afford.
During the campaign, Zohran Mamdani said he'd try to revive Local Law 97 implementation by working with the state to extend the J-51 tax break, which lets co-op owners deduct climate improvement costs from their property tax bills, and he'd also use the City's own purchasing power to more affordably buy thousands of electric heat pumps to then be resold to building owners at cost.