Baablu's Natural Disasters mod adds eight disasters that can strike your world:

• Earthquakes: The earth shakes, and lava-filled chasms open around you.
• Lightning Storms: Clouds cover the sky, and lightning falls upon the land.
• Meteors: Meteors fall from space, aimed directly at you.
• Nukes: If you see the mushroom cloud rising, run.
• Sinkholes: A giant circular hole appears in the ground without warning.
• Tornadoes: The strength of the wind in these throws blocks, mobs, and players around hard.
• Tsunamis: A huge wave washes everything away. Don't get caught in the current!
• Zombie Apocalypses: Super-strong zombies come out of the ground. They're fast and powerful.

You can configure the mod using the M-Values editor in your pause button (it looks like a witches' hat).

You can trigger a disaster using the /spawn_natural_disaster command.

Disasters only start spawning after you run /disaster_spawning true!