What factors associated of a volcano eruptions may cause the decrease in the earths average temperature for a few years?

Volcanic eruptions can lead to a temporary decrease in the Earth's average temperature primarily due to the release of large quantities of ash and sulfur dioxide (SO2) into the atmosphere. The ash can block sunlight, while SO2 can form sulfate aerosols that reflect solar radiation away from the Earth. This phenomenon can result in a cooling effect that may last for a few years, disrupting normal climatic patterns. Notable examples include the eruption of Mount Pinatubo in 1991, which caused significant short-term global cooling.