Final answer:
The 1991 Mt. Pinatubo eruption released aerosols into the atmosphere that caused global temperatures to drop, due to haze-effect cooling.
Step-by-step explanation:
The eruption that caused a plume which reached the stratosphere, forming sulfuric acid that blocks solar radiation and causing lower global temperatures was the 1991 Mt. Pinatubo eruption. This massive eruption ejected SO₂ aerosols into the atmosphere, which reduced the amount of sunlight reaching Earth's surface enough to lower global temperatures by 0.4 °C.
The global cooling effect from volcanic eruptions is also known as haze-effect cooling, a phenomenon where dust, ash, or other suspended particles block out sunlight.