Desert/Ice Planet

With this concept, Earth has been half consumed by snow and half consumed by desert. There's a fine split of survivable land between each side of the world. The sun only shines on the desert, creating a hot, dry, dead biome. The snowy side is always consumed in darkness, and temperatures quickly dive into the triple negatives. Abandoned cities are covered in ice and sand, and the earth has cracked apart after having been frozen. The only remaining lifeforms are the most resilient creatures that can withstand extreme temperatures and lifestyles. The only thing that matters for humans is how to survive each day when the entire world is against you.