Mount Ruang in Indonesia recently unleashed a series of explosive eruptions, spewing ash and volcanic gases high into the atmosphere. While the immediate dangers of volcanic activity persist, scientists are now focusing on the eruption’s potential long-term effects on weather and climate.

Volcanoes can temporarily cool the planet by injecting gases into the upper atmosphere. However, experts predict Mount Ruang’s impact will be minimal. Dr. Greg Huey, chair of Georgia Tech’s School of Earth and Atmospheric Sciences, explains that the volcano’s influence on daily weather patterns near Mount Ruang, such as temperature, rainfall, and cloud cover, will likely be short-lived.

Volcano Basics:

• Mount Ruang, a stratovolcano in North Sulawesi, Indonesia, has erupted multiple times recently. Stratovolcanoes are known for their explosive eruptions due to gas buildup within their conical shape.
• Volcanic ash typically consists of crushed rock, minerals, glass particles, and gases like water vapour, carbon dioxide, and sulfur dioxide.
• Ash clouds can generate impressive lightning displays due to the static electricity produced by the particles colliding.
• The heavy nature of volcanic ash leads to rapid settling and a temporary cooling effect as sunlight gets blocked.

The High-Reaching Gases:

Some of the gases released by Mount Ruang’s eruptions reached the stratosphere, the layer above the troposphere where all weather phenomena occur. This dry region typically only allows long-lived gases (lasting decades) to enter naturally. Volcanic eruptions are a rare exception, allowing short-lived gases like sulfur dioxide and water vapour to reach the stratosphere.

Potential Cooling Effect:

Once in the stratosphere, sulfur dioxide and water vapour combine to form sulfuric acid aerosols. These tiny droplets form a hazy layer that can linger for up to three years, reflecting sunlight into space and potentially causing global cooling. The magnitude of this cooling effect depends on the amount of gas that reaches the stratosphere.

For reference, the 1991 eruption of Mount Pinatubo in the Philippines, the most enormous sulfur dioxide cloud ever measured, released over 17 million tons of gas. This resulted in a global temperature decrease of about 0.5 degrees Celsius for roughly a year.

Current estimations suggest Mount Ruang has released around 300,000 tons of sulfur dioxide, with uncertainties concerning how much reached the stratosphere. While significant, this amount pales in comparison to the extreme case of Mount Pinatubo.

While Mount Ruang’s eruption highlights the potential of volcanoes to influence climate, its impact is likely minor. Scientists are monitoring the situation and its short-term effects on local weather patterns. This event serves as a reminder of the power of volcanoes, even if human-caused factors might dwarf their influence on global climate change.