Earth (2016)

Doom 2016
Earth at the time of Doom 2016 is heavily populated and prone to energy shortages. Thus the discovery of Argent Energy on Mars (2016) was a huge boon, allowing nearly limitless energy potential. UAC (2016) was megacorporation created by Samuel Hayden to mine Argent Energy as well as research archaeological sites in the dimensions beyond.

Doom Eternal
In Doom Eternal, the forces of Hell are shown to have overrun the planet.