Fossil fuel companies are already grappling with the risks posed by climate change, from the physical threats of extreme weather to the challenge of switching to cleaner energy. Now they have a new item rising up their list of worries: liability lawsuits.  Over the past two years, a growing number of legal cases in the US – brought by cities, counties, and the State of Rhode Island – are seeking damages from energy companies for a litany of climate-related problems. Baltimore wants compensation for the cost of retrofitting storm drains to prepare for worsening storms. In San Francisco, the city says it will cost $5bn to upgrade the city’s sea wall to prepare for higher sea levels.

Meanwhile, Rhode Island expects coastal properties worth $3.6bn to be under threat by the end of the century.  Taken together, these lawsuits amount to a legal onslaught that climate  activists hope will have a profound financial impact on oil and gas producers, by imposing huge penalties. The example they draw on is the years of litigation against tobacco companies that culminated in a settlement guaranteeing $206bn in payments to 46 US states over the first 25 years.

Sheldon Whitehouse, a democratic Senator from Rhode Island known for his climate activism, said the threat of litigation is a major worry for oil companies at the moment. “They are frightened at the prospect of liability at what they have done, and they are scared of courts.”

He said the comparison with the tobacco lawsuits is apt. “If you … pop out the word tobacco, and put in the word fossil fuels; pop out the word health, and put in environmental harms. The complaint writes itself,” he said.  One crucial difference, however, is that the climate cases are not yet on the scale of the tobacco litigation – none of the lawsuits have succeeded yet, and several have been thrown out.

At present there are more than a dozen climate liability cases underway in the US: 10 brought by counties, four brought by major cities (New York City, San Francisco, Oakland, Baltimore) and one by a state (Rhode Island). The next cities to file climate-related lawsuits are likely Honolulu, and Washington, DC, which has already put out a call for lawyers.  However, the energy companies and the lobby groups that represent them are skeptical that these cases have merit.

“There has been a long history of this litigation that has not been successful, and for good reason,” said Phil Goldberg, special counsel at the National Association of Manufacturers, a lobby group in DC whose members include fossil fuel companies.