The Mayor's office and other city officials announced a plan to divest money set aside for pension funds from fossil fuel companies, with a goal to remove $5 billion in the next five years.
But de Blasio isn't stopping there. "We are going after those who have profited". He added, "What a frightful, disgusting way to profit".
During his press conference, Mayor de Blasio said that New York City was not waiting for the federal government to act.
The oil majors largely dismissed the suit.
Chevron also said the lawsuits only serve special interests.
The legal action and the divestment draw perhaps the starkest dividing line yet between NY and the Trump administration on climate change.
"Reducing greenhouse gas emissions is a global issue and requires global participation and actions", Exxon said in a statement.
That remains to be seen, but the lawsuit does face long odds.
The case against the fossil fuel companies state that they've imperiled the city and cost an enormous amount of money to taxpayers as NY fights flooding and erosion caused by climate change. Filing a lawsuit against oil and gas companies is the solution and the answer to counter the existential threat of fracking. "There isn't anything you can point to and say, 'This is exactly like that case, '" Michael Burger, executive director of the Sabin Center for Climate Change Law at Columbia Law School, said in a Bloomberg interview. City attorneys across the Front Range should use the New York City lawsuit as a template in order to recover damages for their residents and communities for the harm caused by the oil and gas industry. The claim is that ExxonMobil and its peers had a sophisticated understanding of climate change but denied it to the public.
Part of New York City's vulnerability is that it is surrounded by water.
It is yet to be seen if Los Angeles will join the legal action against the fossil fuel industry. This is similar to the lawsuits against big tobacco for deceiving the public regarding the dangers of smoking and cancer.
In afternoon trading, stock prices for the companies were mixed. It's taking some of the most powerful oil companies to task by suing them.
The lawsuit, and similar efforts from several California cities and counties, will focus on the fact that the fossil fuel industry was aware of the dangers of climate change for years, yet actively misled and deceived the public.