Man-made pollution causes damage to the ozone layer, the layer of ozone in the earth's atmosphere protecting it from radiation from space. When volcanoes erupt they expel volcanic aerosols. These aerosols do not cause damage to the ozone, but they interact with chlorine and bromine compounds in the air released by human pollutants. This interaction causes man-made pollution to worsen. Aerosols block the sun's rays, lowering the earth's temperature until they fade after a few days.
The release of large amounts of carbon dioxide causes what is called the greenhouse effect, the increase of the earth's temperature. As the earth's temperature rises, the ice caps melt and the ocean rises. Humans release carbon dioxide through the use of cars, factories, and other pollutants. Volcanic eruptions release carbon dioxide into the air locally, which can travel quickly due to air currents. Large volcanic eruptions may raise the global temperature.
When volcanoes erupt many chemicals and poisons are introduced to the air. The dust and ash released are also a problem. Volcanoes create large amounts of dust by the explosion of rock; this dust mixes with ash and smoke from the volcano. These pollutants quickly travel around the globe through air currents, blocking the sun's light, which cools the earth's temperature. Debris from the explosion may land anywhere in the world.
Sulfur-rich gases from deep in the earth are released into the air during a volcanic eruption. These heated gases rise into the atmosphere and mix with the tiny water droplets found in air. The mixture of water with sulfuric gases creates sulfuric acid, which burns and eats away at the surface of whatever it hits and pollutes the water supply. Due to global air currents, sulfuric acid from a volcano may fall anywhere on earth.