In the Fallout storyline, a nuclear war breaks out between China and America. The subsequent radiation kills a large portion of the world's population. The Earth's landscape turns into a barren wasteland, like this:
Even though in the end, the hero begins to purify the radiation, Earth will never truly be the same.
On the other hand, the outlook on humanity's future is not always so grim. In Halo: Reach, humanity has spread throughout the galaxy and many if not all planets are still very beautiful. Earth may have become covered in cities, but Reach, after years of human habitation still looks like this:
So, we must ask ourselves, would we rather peacefully inhabit the planets of our galaxy, or turn our own home world into a wasteland? Like in Beauty Bleak by Miracle of Sound?