Emergency Skin (Forward collection)

This Novelette from the Forward Collection is winner of a 2020 Hugo Award: "An explorer returns to gather information from a climate-ravaged Earth that his ancestors, and others among the planet’s finest, fled centuries ago. The mission comes with a warning: a graveyard world awaits him. But so do those left behind—hopeless and unbeautiful wastes of humanity who should have died out ages ago. After all this time, there’s no telling how they’ve devolved. Steel yourself, soldier. Get in. Get out. And try not to stare."