With the conversation around global warming heating up in an already-volatile environment, cities across the U.S. are increasingly stepping in to fill the void left by the United States’ withdrawal from the Paris Agreement last year. In fact, recent moves by New York City’s mayor office to sue fossil fuel companies for aiding in causing global warming indicate that, if anything, cities are at the forefront of climate action in the U.S. today. Earlier this month, New York City’s Mayor De Blasio announced plans to sue oil companies, also promising to divest city funds from the industry.

On January 10th, Mayor Bill de Blasio stated that the City of New York is planning on suing a number of oil and gas tycoons for worsening the effects of global warming felt in NYC. “As climate change continues to worsen, it’s up to the fossil fuel companies whose greed put us in this position to shoulder the cost of making New York safer and more resilient,” said de Blasio.

In order to prevent potential damage incurred by natural disasters linked back to global warming, the city is putting together what De Blasio is calling a “resiliency” program. The program will fund improving outdated infrastructure, protecting coastlines, upgrading water and sewage infrastructure, heat mitigation, and public health campaigns to raise awareness on the dangers affiliated with climate change.

The move to prevent global warming-related damage is also linked to divesting the state’s pension fund from fossil fuel companies. Currently, the fund stands at $189 billion and will be reduced by $5 billion as a result of the divestment. The city’s Comptroller Scott Stringer believes that the importance of providing a pension for the city’s nurses, firefighters, and teachers based on ensuring a sustainable future for the planet is key for city officials.

And while there are many, like The Union of Concerned Scientists, who believe fossil fuel companies are deceiving the general public about the potential harms of their products, the move also has opponents. The companies currently being sued by the city include BP, Chevron, ConocoPhillips, Exxon Mobil, and Royal Dutch Shell. Scott Silvestri of Exxon Mobil said to The Independent that he doesn’t believe that this action will create the kind of change that a collective effort can bring. Curtis Smith of Shell said, “The courts are not the venue to address climate change.”

While many believe that De Blasio’s claim is legitimate, Linda Kelly of the National Association of Manufacturers believes De Blasio’s move has political motive. To augment NYC’s position on the lawsuit, seven other cities, all of which are in California, already have or are working towards following in the Big Apple’s steps.

Last week, Los Angeles became the eighth city to hold fossil fuel companies accountable for their hand in worsening global warming. With other initiatives in motion to move the city to renewable energy, Los Angeles Mayor Eric Garcetti is pushing forward local action opposing the Trump administration’s federal agenda that refuses to recognize global warming as an imminent threat. Cities that have filed lawsuits against companies they believe are partaking in the worsening of global warming have cited rising sea levels and an alarmingly high number of wildfires and mudslides seen across the state.

Unlike in New York, Californian cities have the law on their side, with a legal precedent allowing for them to sue companies on grounds of “public nuisance.” And while this makes the legal grounding of the cases far stronger, the Environmental Protection Agency’s rulings on greenhouse gas emissions supersede legal precedent in California law.