New York City Mayor Bill de Blasio announced that he will work with the city council to develop legislation prohibiting the use of natural gas and fuel oil in large buildings, part of a suite of renewable energy and climate policies during his State of the City address.

The announcement signals the nation's most populous city intends to join the growing movement to ban natural gas, which is spreading through California and taking root in the Boston area and Washington state. If passed, the measure would build on a 2019 bill that sailed through city council requiring large buildings to take steps to reduce their carbon footprint.

"Patterned after that extraordinary retrofit law for our big buildings, we are going to take the next step. We will work with the council on a ban, ending the use over the next two decades — ending the use — of oil and gas in our buildings, replacing it with clean electricity," de Blasio said during the Feb. 6 address.

Combating climate change has been a pillar of New York City Mayor Bill de Blasio's tenure and was central to his short-lived bid for the 2020 Democratic presidential nomination.

Source: New York City Mayor's Office

The details of the prohibition and when it would begin to take effect remain unclear. The proposal calls for New York City to stop using gas and other fossil fuels in large building systems by 2040, beginning with government buildings, according to a city hall press release. The mayor's office "will work with lawmakers to ensure that new permits for building systems are aligned with our goal of carbon neutrality by 2050," it said.

Most building gas bans and electrification codes apply to new construction and renovations, though one proposal in Bellingham, Wash., would require property owners to convert to electric heating systems in existing buildings by 2040.

During the address, de Blasio also signed an executive order to block infrastructure that would grow fossil fuel supply in New York City, including power plants, pipelines and terminals. The mayor said the idea of abandoning a fuel source upon which New Yorkers have long depended is hard to accept, but he framed the policy as a matter of survival amid a climate crisis.

"If we don't break this addiction to fossil fuels, it will break us. We have to overcome it and so I am announcing an executive order to end the creation of fossil fuel infrastructure in New York City once and for all," de Blasio said.

The measure comes on the heels of a bitter dispute between New York Gov. Andrew Cuomo and National Grid USA over the state's refusal to permit new gas pipeline capacity into the city and the utility's subsequent ban on new applications for gas service in Brooklyn, Queens, Staten Island and Long Island. National Grid lifted the gas moratorium as part of a November 2019 settlement, but the company is still developing a long-term solution to supply constraints, which could include building a pipeline through New York Bay.

Consolidated Edison Co. of New York Inc., which delivers gas into Manhattan, the Bronx and Westchester County, has recently announced plans to help customers reduce their gas consumption in line with the state's clean energy and greenhouse gas emissions reductions goals.

"We want to help lead the drive towards a clean energy future, and will work with the city and state with their goals to reduce carbon emissions," Con Edison said in a statement after de Blasio's speech. "We are working closely with the city to help establish EV charging stations. We are also working with customers to consider cleaner alternatives to natural gas for their heating and cooking needs."

The climate and clean energy plan unveiled by de Blasio on Feb. 6 included several other measures. It would establish the South Brooklyn Marine Terminal as a hub for staging, installing and operating wind turbines throughout the tri-state area. It also aims to outfit 50,000 small residential buildings with solar panels by allowing New Yorkers to spread the cost of installation over several years.

The city will also seek new hydropower supply agreements in a bid to run government operations purely on renewable energy. The mayor signed another executive order mandating all city vehicles including garbage trucks, ambulances and police cars be replaced or with or converted into electric vehicles by 2040.