Whose work first showed that volcanic eruptions can cool the climate?

The 1815 eruption of Mount Tambora in Indonesia was one of the most powerful eruptions in recorded history. Later scientific study showed that enormous amounts of sulfur aerosols were pumped into the atmosphere, reflecting sunlight and cooling the climate. This caused severe weather anomalies in 1816, remembered as the Year Without a Summer. Crop failures and famine followed in parts of North America and Europe. Tambora became a classic example of how a single volcano can influence global climate.