The "Future" Ninja Turtles are the same Turtles of today, only tomorrow. Or, more precisely, they are the Mutant Ninja Turtles of the 21st century; older, wiser, no longer Teenage. The fact that the Turtles are still alive one hundred years from today is proof of the longevity of their reptilian heritage. The future Turtles were first encountered by today's Teenage Mutant Ninja Turtles when the former came back in time in order to enlist the younger Turtles' aid against the combined might of Armaggon, Verminator-X and the Shredder. They have since appeared several more times in order to help the Mutanimals set up their island headquarters. Inventions created and marketed by Donatello have enable the Turtles to amass great wealth, including the mod-Manhattan skyscraper that is their headquarters (called TurtleCo). While little else has been revealed about their lives it appears that the Turtles now live openly with mankind; the same is true for other mutants as well.
Their world is an Earth held in the cataclysmic grip of a greenhoused atmosphere. The polar ice caps have melted, dramatically raising ocean levels and flooding coastal cities like New York. Environmental refugees struggle for existence while the great biodiversity that once enriched the planet is but a fraction of what it once was. The world has become a harsh place where only the strong, the adaptable, and the wealthy survive.
Teenage Mutant Ninja Turtles
The Mighty Mutanimals
The Rat King
The Gang of Four