Humanity is a failed alien terraforming op: Usually newly uplifted civilizations, with very little intervention after the initial seeding, reliably consume all the surface fuel and turn the place into a nice cool desert, and what's left can be psionically reprogrammed
Plot twist the grad-student in the project forgot to seed the bacteria that could break down fallen trees which meant the local population had to figure it out itselfhttps://youtu.be/b34al8YmQSA