Atheist Walter Sinnott-Armstrong writes, “Even if the value of free will did explain why God allows evil that is caused by humans, it still would not explain why God allows natural evil. Natural evil is evil that arises independently of human actions… The free will defense does not apply to natural evil.” In response to this objection, a few points can be made.
First, natural disasters are actually necessary for life. In and of themselves, these “disasters” are not evil. They actually produce a planet habitable for human life. For instance, if there were no molten core to the Earth (which produces earth quakes), there would be no magnetosphere around the Earth, which protects us from radiation bombardment. Without electromagnetic radiation, nuclear fusion couldn’t occur and stars couldn’t burn. Without floods, surrounding lands lack essential silt and minerals. Without lightning, we would not have nitric oxide, which feeds plants in the rain. Hurricanes and typhoons result from uneven heating around the globe –the clashing of high and low temperatures around the Earth. This problem could be solved, if the Earth was heated by three suns (one at the equator, and two at each pole). However, three suns would destroy our planet in the process! These “disasters” existed before the Fall, and they were originally designed for a good purpose.
Second, when the first humans fell, they were volitionally throwing themselves into a world of cause and effect. Before the Fall, the first humans were either supernaturally protected from disasters in the Garden, or they had supernaturally protected bodies. That is, if a hurricane swept through the Garden, the first humans wouldn’t have been hurt by it (see Jesus’ resurrected body Acts 1:9). By throwing off God’s leadership in the beginning, the early humans were throwing off his protection, hurling themselves into a hostile universe. The “thorns and thistles” and “pain in childbirth” existed before the Fall, but the effects did not exist until after it. By seeing the chaos of nature, the first humans would have been given additional reason not to rebel from God in the first place. Therefore, natural evil could be bound up with the first human decision to rebel against God’s leadership.
Third, Jesus taught that natural evil was due to a fallen world. Jesus taught that natural evil was a result of human sin in general, rather than human sin in particular. Jesus’ interlocutors wanted to know if a man was born blind because of his sin or his parents, but Jesus retorted that it was neither (Jn. 9:1-3). Jesus taught that the moral evil of Pilate (Lk. 13:1) and the natural evil of the tower of Siloam (Lk. 13:4) were not the result of the victims’ sinfulness.
Fourth, demonic activity could result in some natural evil. This explanation is not popular for explaining natural evil. It seems anti-scientific to claim that demons are causing natural evils. While we shouldn’t become fanatical regarding this explanation, we shouldn’t avoid it altogether, either. The Bible teaches that some of the natural evil in our world is the direct result of the violent spiritual realm around us (Job 1:16, 19; 2:7; Mk. 9:20; Lk. 13:10-16; Mt. 17:14-15). Two of the greatest living Christian philosophers –Alvin Plantinga and Richard Swinburne –believe that this is a distinct possibility. While radical demonic paranoia should be avoided, this should still remain a possible answer for natural evil. In this way, freewill could still be the cause of some natural evil.
Fifth, human freewill affects natural evil. The physical evils in our lives could be the result of our sinful choices (e.g. cigarette smoker getting cancer; obese person having heart conditions). In a general sense, it is possible that our pollution of the Earth is a failed stewardship, which has brought more natural disasters upon humanity, as well (Gen. 1:28; Is. 24:3-5). Moreover, our freewill often amplifies natural evil. Consider the warlords in Haiti after the Earthquake, hoarding donated supplies, or consider the men looting in New Orleans after the flood. Often, natural evil isn’t that bad; it is the moral evil that takes advantage of natural disasters.
To conclude, the Bible teaches that God can use disasters to bring about ultimate good (Rom. 8:28), even if we can’t currently understand God’s purposes in permitting them (Deut. 29:29; Rom. 11:33; 1 Cor. 13:12). None of these arguments is conclusive, but hopefully, this helps give a framework for understanding natural evil.
 Craig, William Lane., and Walter Sinnott-Armstrong. God?: a Debate between a Christian and an Atheist. Oxford: Oxford UP, 2004. 93.
 See Rich Deem’s article “Where is God When Bad Things Happen? Why Natural Evil Must Exist” for a theodicy on this subject. http://www.godandscience.org/apologetics/natural_evil_theodicity.html.
 Plantinga, Alvin. God, Freedom, and Evil. Grand Rapids: Eerdmans, 1977. 58-62.
 Swinburne, Richard. The Existence of God. 2nd ed. Oxford: Clarendon, 2004. 239-40.