Volcanic Ash's Deadly Effects Ash fall, however, is more than an inconvenience. It can be lethal to plants, wildlife, and humans. Swirling particles of ash in the atmosphere generated lightning, which in turn ignited hundreds of forest fires near the volcano. Autopsies revealed that most of the human deaths in the blast area resulted from asphyxiation, from inhaling hot volcanic ash during the first few minutes of the eruption. As the ash settled to the ground, it also took its toll.
Volcanic ash can also affect aircraft operations.
Impact on Climate Volcanic eruptions can also affect climate and weather patterns. This haze, which can remain in the atmosphere for years, reflects the sun's radiation and reduces surface temperatures. For example, more than a year after the April 1815 eruption of Indonesia's Tambora volcano, its effects were felt. The eruption of Tambora ejected 150 times more ash than Mount St. Helens in 1980. The 1980 eruption of Mount St. Helens was only an inkling of the destructive potential of a volcanic eruption.