Turn your world into a flaming desert during the day and arctic wasteland at night
1.7.10 - v1.0 - [ version broken holdon ]
Extreme Climates is a mod that makes the sun extremely big and the moon extremely small (note: this only activates once your world becomes 1 day old so you have time to survive)
This means that during the day, grass dies, water evaporates, and flammable things burn. At night the opposite happens, the air becomes extremely cold, layers of permafrost begin to build up, and everything slowly becomes covered in layers of ice.