Volcanic eruptions can have significant impacts on climate, both in the short and long term.1 Here’s a breakdown:
Short-Term Cooling:
- Sulfate Aerosols: Volcanic eruptions release large amounts of sulfur dioxide (SO2) into the atmosphere.
- This SO2 reacts with water vapor to form sulfate aerosols, tiny particles that reflect sunlight back into space.
- This reduces the amount of solar radiation reaching the Earth’s surface, leading to temporary global cooling.
- Examples: The eruption of Mount Pinatubo in 1991 caused a global cooling of about 0.5°C for a couple of years.
Long-Term Warming:
- Greenhouse Gases: Volcanoes also release greenhouse gases like carbon dioxide (CO2) and water vapor into the atmosphere.
- While volcanic CO2 emissions are relatively small compared to human activities, they can contribute to long-term warming over geological timescales.
Other Impacts:
- Changes in Atmospheric Circulation: Volcanic eruptions can disrupt atmospheric circulation patterns, leading to changes in weather patterns and regional climate variations.
- Ozone Depletion: Volcanic eruptions can release chlorine into the stratosphere, which can contribute to ozone depletion.
Key Points:
- The magnitude of climate impacts depends on the size and intensity of the eruption, as well as the types of materials ejected.
- The effects of volcanic eruptions on climate are typically short-lived compared to the long-term impacts of human activities, such as greenhouse gas emissions.