This document discusses how aerosols from large volcanic eruptions can cause short-term global cooling by reflecting sunlight back into space. It provides examples from the 1991 Pinatubo eruption and earlier eruptions that injected sulfur dioxide aerosols high into the atmosphere, resulting in global temperature decreases of up to 3 degrees Celsius. The document also mentions proposed methods for climate engineering that could intentionally send aerosols into the atmosphere to offset global warming effects.

1. Global Cooling usingAerosolBy: Wei He

2. Global WarmingGlobal Warming: the gradual increase in the average global temperature.

3. Global Warming vs. CoolingFrom IPCC (Intergovernmental Panel on Climate Change) Report

4. AerosolAerosol: suspension of tiny particles in the air

5. Aerosol: Direct Effect and Indirect EffectDirect Effect: aerosol in Earth’s stratosphere reflects sunlight away from Earth. Indirect Effect: aerosol in Earth’s troposphere allows cloud formation. Clouds then cool the earth by reflecting sunlight back into space.Scientific ExperimentsLarge Volcanic eruptions can send particles at high as the stratosphere, and the particles can spread around the world1991 Pinatubo Eruption

6. Experimental Results1982 El ChichonEruption: 7 million metric tons of SO2 caused global cooling of 0.3°C.1991 Pinatubo Eruption: 20 million metric tons of SO2 caused global cooling of 0.5°C1815 TamboraEruption: Largest eruption in recorded history released unknown amount of SO2. Global Cooling of about 3°C.Data from U.S Geological Survey

7. Methods of Climate EngineeringSend aerosol into earth’s atmosphere using balloons, artilleries, or airplanes.