San Francisco and Oakland sued five major oil companies in the state courts on Wednesday in the latest attempts to hold fossil fuel producers accountable for the effects of climate change.

The parallel lawsuits call for the companies to pay what could become billions of dollars into a fund for the coastal infrastructure necessary to protect property and neighborhoods against sea level rise in the sister cities, which face each other across San Francisco Bay.

The moves follow similar lawsuits filed against 37 fossil fuel companies earlier this summer by three other coastal California communities at risk from sea level rise.

The flurry of litigation relies on the theory that the biggest and richest oil companies in the world should somehow be forced to pay the price for the damages that are becoming steadily more apparent from climate change, which the industry’s critics say can be directly linked to the emissions that come from burning their products.

In the latest lawsuits, the cities argue that ExxonMobil, BP, Chevron, ConocoPhillips and Royal Dutch Shell have known for decades about the climate risks created by their products while carrying out campaigns to “deceive consumers about the dangers.”

“Global warming is here, and it is harming San Francisco now,” San Francisco’s lawsuit begins. “This egregious state of affairs is no accident.”

The lawsuits claim that the companies created the public nuisance of climate change impacts by producing fossil fuels, whose use is the principal cause of global warming.

“These fossil fuel companies profited handsomely for decades while knowing they were putting the fate of our cities at risk,” San Francisco City Attorney Dennis Herrera said in announcing the lawsuits. “Instead of owning up to it, they copied a page from the Big Tobacco playbook. 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.”

Among other evidence, the city’s lawsuit cites records uncovered by InsideClimate News in its 2015 investigation into Exxon’s history of cutting-edge climate science research in the 1970s and ’80s and how the oil giant’s leadership then pivoted to pour resources into fighting climate policies. It also points to decades of scientific evidence connecting greenhouse gas emissions to impacts including rising global temperatures and sea level rise.

“Reducing greenhouse gas emissions is a global issue that requires global engagement and action,” Chevron said in a statement after the lawsuits were filed Wednesday. “Should this litigation proceed, it will only serve special interests at the expense of broader policy, regulatory and economic priorities.”

Herrera and Oakland City Attorney Barbara J. Parker said billions of dollars worth of property in their cities are within 6 feet of current sea levels—at least $10 billion in public property in San Francisco alone. In both cities, the sewer systems also face risks of damage and sewage overflows from rising sea levels. Low-lying runways are another vexing problem. The city attorneys also stressed that some of their most vulnerable residents are at risk.

“Global warming is an existential threat to humankind, to our ecosystems and to the wondrous, myriad species that inhabit our planet,” Parker said. “The harm to our cities has commenced and will only get worse. The law is clear that the defendants are responsible for the consequences of their reckless and disastrous actions.”