From Guangzhou in China to London in the UK, cities around the world are bracing for sea level rise so severe that it could cause mass exoduses.

For some US cities like San Francisco and Oakland, leaders refuse to shoulder the burden of mitigation and adaptation alone, according to a San Francisco city press release.  

The two coastal Californian cities are suing five major oil companies for the future costs of defending against sea level rise, arguing that these corporations directly accelerated climate change while knowing the damage they were causing and at the same time lobbying to fight climate regulations that would reduce greenhouse gas emissions.

This behavior, according to the lawsuit, resembles the campaign of misinformation waged by the tobacco industry in the 20th century.

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Separate lawsuits have been filed against BP, Royal Dutch Shell, Exxonmobil, Chevron and ConocoPhillips. City attorneys from San Francisco and Oakland are asking for a fund to be set up to pay for the escalating costs of climate change.

“They launched a multi-million dollar disinformation campaign to deny and discredit what was clear even to their own scientists: global warming is real, and their product is a huge part of the problem,” Dennis Herrera, San Francisco’s city attorney, told The Independent.

“Now, the bill has come due,” he said. “It’s time for these companies to take responsibility for the harms they have caused and are continuing to cause.”

By the end of the century, it’s estimated that global sea levels could rise as much as eight feet, causing billions of people to be displaced from their homes.

In San Francisco and Oakland, whole neighborhoods could be submerged, causing the destruction of billions in real estate and essential infrastructure like airports, according to analyses offered by the cities.  

Consequently, the two cities are looking to secure billions of dollars to fund necessary protection measures.

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San Francisco currently has a project planned for $350 million to protect coastal areas.

“Global warming is an existential threat to humankind, to our ecosystems and to the wondrous, myriad species that inhabit our planet,” Barbara Parker, city attorney for Oakland, told The Independent.

“These companies knew fossil fuel-driven climate change was real, they knew it was caused by their products and they lied to cover up that knowledge to protect their astronomical profits,” she said.

The companies targeted by the lawsuit argue that they aren’t responsible for the effects of climate change and that, in any case, lawsuits aren’t the best way to go about dealing with a globally diffused problem.

A spokesman for Chevron said that legal action would not help the fight against climate change.

“Reducing greenhouse gas emissions is a global issue that requires global engagement and action,” Melissa Ritchie, a spokesman for Chevron, told the Los Angeles Times.

“Should this litigation proceed, it will only serve special interests at the expense of broader policy, regulatory, and economic priorities,” she said.

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Other companies agreed.

"We strongly support the agreement in Paris to limit global warming to two degrees Celsius or less, but we believe climate change is a complex societal challenge that should be addressed through sound government policy and cultural change to drive low-carbon choices for businesses and consumers, not by the courts,” Shell said in a statement.

This lawsuit isn’t the first of its kind in the US or even in California.

Earlier in the year, three California communities filed a lawsuit against 37 fossil fuel companies for their role in stoking climate change.

How these lawsuits will play out in the courts is unknown, but there has been mounting evidence in recent years of how blame for climate change should be apportioned.

In fact, one analysis found that 100 companies are responsible for 71% of all greenhouse gas emissions since 1988. And a recent investigation found that ExxonMobil has deliberately lied for decades about climate change.

This evidence and more will likely be used against the companies in court and could sway the ultimate decision.

Whatever the outcome, one thing is clear — communities everywhere are getting anxious about how to cope with climate change.