Climate “superfund” bills, based on the principle that oil companies should pay costs associated with climate change, are gaining ground in state legislatures around the country.

But it’s unclear whether the only two states to have passed such laws, New York and Vermont, will be able to defend them from legal challenges. The Justice Department, industry groups and other states have all sued to block the laws.

The laws borrow their superfund names from the long-running federal program that requires companies to pay to clean up industrial sites they polluted.

Despite the legal efforts to kill the newer, climate-focused versions of these laws, states around the country are proposing similar measures. In Maine last week, one such bill passed a committee vote, and others were recently introduced in Illinois and New Jersey, with one also expected soon in Connecticut. Related measures are pending in several other states.

Proponents say the measures are necessary to fund urgent public projects like fortifying coastal areas against flooding. “It’s not a question as to the billions and billions of dollars that have to be spent to deal with resiliency” against climate-related threats, said State Senator John McKeon of New Jersey, who represents suburban areas across the Hudson from New York City. “It’s a matter of who’s going to pay for it.”

He said the bill he sponsored has been renamed the “Polluters Pay to Make New Jersey Affordable Act,” in a nod to concerns about the cost of living. While it already faces opposition from business groups, Mr. McKeon said that it would benefit businesses in the state.