How would a volcanic eruption affect global climate?
Check these sites.
http://earthobservatory.nasa.gov/Features/Volcano/
http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html
A volcanic eruption has the potential to significantly impact global climate. When a volcano erupts, it releases a large amount of volcanic gases, particulate matter, and ash into the atmosphere. These emissions can have both short-term and long-term effects on the Earth's climate system.
In the short term, volcanic eruptions can cause immediate cooling of the planet. The released sulfur dioxide (SO2) gas reacts with water vapor in the atmosphere to form sulfate aerosols, which reflect incoming sunlight back into space. This results in a decrease in solar radiation reaching the Earth's surface, leading to a temporary cooling effect. This cooling effect can last for a few years following a large volcanic eruption.
However, the long-term effects of volcanic eruptions on global climate are more complex. Volcanic aerosols and gases can have different impacts depending on their composition and altitude in the atmosphere. While the reflective aerosols lead to cooling, volcanic emissions also contain carbon dioxide (CO2) - a greenhouse gas - which can contribute to long-term warming. The net effect depends on various factors, such as the amount of sulfur dioxide and carbon dioxide released, the duration of the eruption, and the altitude of the volcanic plume.
Moreover, volcanic eruptions can also cause changes in weather patterns. The release of large amounts of ash and aerosols into the atmosphere can affect cloud formation and precipitation, leading to regional changes in rainfall patterns.
To understand the specific impacts of a volcanic eruption on global climate, scientists use computer models and observations from past volcanic events. They study factors such as the eruption size, composition of volcanic emissions, and atmospheric conditions to estimate the impact on the Earth's climate system. These models help them simulate the spread of volcanic aerosols in the atmosphere and their subsequent effects on temperature, precipitation, and overall climate patterns.
Overall, while volcanic eruptions initially cause a cooling effect due to the release of reflective aerosols, their long-term impact on global climate depends on various factors and can be both cooling and warming. Scientists continue to study volcanic eruptions to improve our understanding of their effects on climate and refine climate models.