Boston Mayor Michelle Wu signed an ordinance Monday designed to divest the city from fossil fuels.

The ordinance will prohibit the use of public funds from being invested in the stocks, securities or other obligations of any company that derives more than 15% of its revenue from fossil fuels.

The ordinance also extends to companies deriving more than 15% of revenue from tobacco products or private prison industries.

Wu, a former city councilor sworn in as mayor last week, said the move is the culmination of a yearslong push to distance Boston from the fossil fuels that are helping drive the climate change that is threatening the coastal city.

“This is deeply personal for many of us and urgent,” Wu said during a signing ceremony at Boston City Hall. “My older son Blaise was born in the first year they I served in this building and the first year that we started to hear it was the hottest year ever on record. Since then, his six years alive on this planet have each been our hottest on record.

“We’re moving quickly to make sure that Boston will set the tone for what is possible for that brightest greenest future for all of our kids," Wu added.

The ordinance will pull $65 million immediately out of the fossil fuel industry, said Boston City Councilor Lydia Edwards, a supporter of the ordinance. The measure was unanimously approved by the Boston City Council last week.

U.S. Sen. Edward Markey said leaving fossil fuels in the past is good for the city and its residents.

“We are making the correct investment decision for our country,” said the Democrat and supporter of the national Green New Deal. ““What Boston represents here today is the future.”

#Boston mayor divests vulnerable city from #FossilFuels. #USPoli

Environmentalist and author Bill McKibben also hailed the move.

“Today Boston has a claim at least for a day to being the greenest city in the country,” McKibben said.

As a coastal city, Boston is bracing for the increasing impact of climate change and rising sea waters.

A report unveiled earlier this year concluded, for example, that Boston’s subway system faces a severe threat from rising seas over the next 50 years that could cause flooding and cut critical links around the city.

Massachusetts Bay Transportation Authority, which operates the Boston area public transit system, is working on longer-term mitigation projects and has directed nearly $2 million to a number of short-term projects to prevent flooding on the Blue Line, one of the city’s four major subway lines.

Boston has the oldest subway system in the country.

City officials did immediately not respond to inquiries about whether any current investments would be affected by the ordinance.

There have been other recent moves to divest from fossil fuels.

Harvard University President Lawrence Bacow announced this year that the university will divest itself from holdings in fossil fuels.

And in January, New York City officials announced that two pension funds for city workers will pull an estimated $4 billion in investments from fossil fuel companies in order to promote clean energy use.

Not every government-led initiative meant to address climate change is successful.

Just last week, Republican Gov. Charlie Baker abandoned his administration’s ambitious plan to create a multistate compact aimed at dramatically curbing greenhouse gas pollution caused by transportation after the deal failed to gain traction in other states.

The ordinance signed Monday was one of the first major policy actions by Wu, who was sworn in last week.

Keep reading