In one case, Judge William Alsup of Federal District Court in San Francisco has suggested that the federal courts could still hear such cases. He kept the suits filed by San Francisco and Oakland and ordered a “tutorial” on climate change to familiarize himself with the scientific issues before setting a trial. In another case, Judge Vincent Chhabria — also of Federal District Court in San Francisco — sent the cases of California’s San Mateo and Marin counties and the City of Imperial Beach to state court.

Exxon has said its opponents are stifling “its First Amendment right to participate in the national dialogue about climate change and climate policy.” And, it has argued that it is a victim of a “conspiracy” brought by environmental zealots funded by activist philanthropists like the Rockefeller family.

In addition, in a line of counterattack , the company has argued that while the lawsuits against it claim that “imminent sea level rise presented a substantial threat,” municipalities and counties did not disclose the threat of climate change in their bond offerings.

The National Association of Manufacturers , which supports the fossil fuel companies, has focused on that point in a spirited campaign against the communities and their lawyers. In April, the group’s Manufacturers’ Accountability Project sent a letter to the Securities and Exchange Commission demanding an investigation of “potential wrongdoing” by those suing. When the Colorado case was announced, the group denounced the “baseless lawsuit” as “another example of trial attorneys attempting to enrich themselves at the expense of manufacturers and manufacturing workers.”

Daniel A. Zarrilli, New York City’s chief resilience officer, rejected the industry’s argument that local governments are being enticed into filing the suits by trial lawyers. “They’re going to throw a lot of things at the wall and see what sticks,” he said.

While most of the communities and environmental groups involved in these lawsuits can be considered on the liberal side of the political spectrum , one of the groups collaborating on the Colorado cases is decidedly not: the Niskanen Center, a libertarian policy group in Washington with a climate focus.

Jerry Taylor, the group’s president, said there was a conservative case for the suits. Rather than push for regulations, he said, it is better to deal with climate change in the courts, as a property rights issue.