Question

O large volcanic events usually cause global warming or cooling? What is the primary mechanism for this? Do these effects last on the order of days, years, centuries, or millennia?

A. Cooling; due to the release of sulfur dioxide, which forms aerosols
B. Warming; due to increased carbon dioxide emissions
C. Cooling; due to decreased carbon dioxide in the atmosphere
D. Warming; due to the release of methane and nitrous oxide

Answer 1

Large volcanic events typically cause global cooling due to sulfur dioxide emissions that form sunlight-reflecting aerosols, leading to haze-effect cooling that lasts for a few years.

Step-by-step explanation:

Large volcanic events usually lead to global cooling, not warming. The primary mechanism is the release of sizable amounts of sulfur dioxide during these eruptions, which form aerosols in the atmosphere. These aerosols can scatter and reflect sunlight away from Earth, leading to a short-term cooling effect known as haze-effect cooling. Such a cooling effect can last from one to a few years before dissipating. This was observed in 1783 when the eruptions in Iceland resulted in significantly lower winter temperatures in Europe and North America during the following years due to the haze-effect cooling caused by released volcanic aerosols.