This is desperation time. Given that CO2 pollution results promise from moderate to extreme environmental disaster world wide, some portion of people are quite worried and, people being people, another portion of people are doing everything they can to keep business as usual going.
A US state suing an oil company might not be the best venue to force action but courts have been used repeated to force societal change and so it's not impossible Ma could get a result
Exxon being punished isn't an important end-goal but actually forcing the oil industry to acknowledge CO2 pollution might be useful in forcing regulation stopping it (and yes, believe that the state directly forcing a decrease in CO2 is the only way that we can put a dent in greenhouse gas production. Carbon credit and even a CO2 tax are insufficient).
A US state suing an oil company might not be the best venue to force action but courts have been used repeated to force societal change and so it's not impossible Ma could get a result
Exxon being punished isn't an important end-goal but actually forcing the oil industry to acknowledge CO2 pollution might be useful in forcing regulation stopping it (and yes, believe that the state directly forcing a decrease in CO2 is the only way that we can put a dent in greenhouse gas production. Carbon credit and even a CO2 tax are insufficient).