Where did humanity go after leaving the world in Pokémon Pokopia?

In Pokémon Pokopia, humanity departed for outer space.

The game's backstory explains that unexplained environmental changes made the world increasingly inhospitable. Humans eventually left the planet, but they could not take all of their Pokémon with them. Instead, they stored Pokémon in a massive computer system designed to continue operating after the departure.

This history explains why Ditto encounters an abandoned landscape populated by Pokémon but lacking human communities. It also gives the habitat-restoration missions a larger purpose: rebuilding livable environments for Pokémon left behind after the human evacuation.

The destination is sometimes confused with a different kind of disappearance, such as humans moving to another Pokémon region. Pokopia's story specifically connects the evacuation to outer space. The rocket reveal near the conclusion reinforces that the mysterious structure involved in the story was not merely a tower or ordinary facility.