This paper discusses the positive and negative effects of volcanoes on the environment. Volcanoes have affected earth's past history and will continue to affect future. This paper discusses the types of damage caused by volcanoes such as lahars, pyroclastic flows, debris avalanches, landslides, and tsunamis. The paper discusses how people often feel the most damage caused by volcanoes are killing people, but actually many of the long-term effects create more hazards.