How much more economic activity than the average citizen?
Anyway I suppose flying commercial and accordingly taking on a less aggressive tour schedule would help her reduce her footprint. I only know a few her hits (mostly that are more club friendly) personally but acknowledge she’s going to be responsible for more of everything in the aggregate. Way more environmental damage. Way more endorphins.
So back to “how can she reduce her footprint” while still doing her Swiftie thing? Sure there are plenty of ways.
She might do more economic activity but for who? Organizers? Herself? Scalpers? If she has that much money to be considered a billionaire maybe she could do something to cover her footprint. Plant some trees or donate to some organization that occupy with saving the planet.