Imagine there are ozeans, and they slowly dry away, evaporatintg to space. The water gets more saltier with every season, uvw rays grill what ever is left of your living space.

All you can do is sleep through longer and longer winters in this brine, waiting for the sun to thaw the salty mud. Or you retreat, using some weak smoker in the depths as a provider of energy, following it ever deeper down, the world freeze drying behind you.

I know its frowned upon by some, but imagine we could create a sort of floating spirondella, and set them free in venus atmosphere. Venus beeing a dead planet, cooled by a floating forrest sounds actually more realistic to me terraformingwise then changing mars.