First they tried suing the utility companies. Then they tried suing the automakers. They even tried suing oil companies on behalf of an Alaskan village in danger of being inundated by oil-fueled rising sea levels. Each approach ended when courts said that the judiciary branch wasn’t the right place to address human-induced global warming, a problem so big it requires a coordinated international response that only legislators can implement. Now private plaintiff lawyers and their allies in government are trying a new strategy: Suing under state-law theories of public nuisance. San Francisco and several other California cities and counties have...