When dust and ash particles from a volcanic eruption block out sunlight and reduce solar radiation, earth experiences the . this results in temporary climate cooling.

When volcanoes erupt, they emit a mixture of gases and particles into the air. Some of them, such as ash and sulphur dioxide, have a cooling effect, because they (or the substances they cause) reflect sunlight away from the earth. Others, such as CO2, cause warming by adding to the the greenhouse effect.