One classification of evil is natural evil, those evils that are explained by laws of nature, without need for a personal agent. But is it appropriate to call natural disasters evil? The usual connotation of evil is something that pertains to personal agents so that it seems to me that to classify natural disasters evil would seem misleading. If my argument is valid, why does "natural evil" become a common term in the discussion of the problem of evil?
My hunch is that the term "natural evil" arose from the older label "the problem of evil" as a way to divide the data into events caused by agents and events not caused by agents. I don't think the choice of terminology is significant. One can refer to the problem of evil as the "problem of suffering" and then distinguish suffering caused by agents from suffering not caused by agents. The background assumption in any case is that suffering -- unlike, say, breathing -- isn't morally neutral: all else being equal, suffering is something undesirable that any morally sensitive person tries to prevent or relieve. So I don't think that substituting "suffering" for "evil" makes a difference to the problem or its solution. From my perspective, the important point is that if an omniscient and omnipotent God exists, then any suffering that occurs anywhere, regardless of its cause, is suffering that God chooses to permit .