Volcanic eruption discharge carbon dioxide but they may also emit aerosols such as volcanic ash and dust and sulfur dioxide. Aerosols are liquids and solids that float around in the air. They may also include soot, dust, salt crystals, bacteria, and viruses. Aerosols scatter incoming solar radiation, causing a slightly cooling effect. Volcanic aerosols can block a percentage of sunlight and cause a cooling that may last for 1-2 years. In volcanic eruptions, volcanoes release ash particles and sulfur dioxide into the stratosphere. The larger particles settle after a few days while the sulfur dioxide combines with water vapor to form sulfuric acid and sulfate particles known together as sulfuric aerosols. Winds transport these sulfurous aerosols around the planet in easterly or westerly directions. For this reason, volcanoes that erupt at lower latitudes are more likely to cause hemispheric or global cooling. Volcanoes that erupt at higher latitudes are less likely to cause cooling because the sulfurous aerosols are confined to wind patterns surrounding the poles. Carbon dioxide is released when magma rises from the depths of the Earth on its way to the surface. Our studies here at Kilauea show that the eruption discharges between 8,000 and 30,000 metric tons of CO2 into the atmosphere each day. Actively erupting volcanoes release much more CO2 than sleeping ones do.