How do volcanoes affect the climate after a major eruption?

When a large explosive eruption reaches the stratosphere, sulfur gases can convert into tiny sulfate particles. These aerosols reflect some incoming sunlight back to space and can temporarily cool Earth’s surface. The 1991 eruption of Mount Pinatubo is a classic example, and it caused measurable global cooling of about half a degree Celsius for a period of time. Smaller eruptions usually have more local effects, but major ones can influence weather patterns and agricultural conditions worldwide. The climate impact depends on eruption size, sulfur content, and how high the plume rises.