Water vapor doesn't remain in the air for long. Unlike CO2 and sulfur dioxide, water vapor condenses to liquid water and falls out of the atmosphere. So a volc

Water vapor doesn't remain in the air for long. Unlike CO2 and sulfur dioxide, water vapor condenses to liquid water and falls out of the atmosphere. So a volcano's water vapor effects (warming) can last days, while the sulfur dioxide effects (cooling) will last months or years.