Since April 16, the Mount Ruang volcano in Indonesia has erupted at least 7 times, drawing attention to the potential impact of volcanic eruptions on weather and climate.
The volcano has emitted large amounts of volcanic ash clouds and gases into the high altitude of over 65,000 feet—about 25,000 feet higher than the typical cruising altitude of commercial airplanes.
Injecting gases into the upper atmosphere, the volcano could have short-term effects on climate, potentially causing a global cooling of temperatures. However, according to a report by CNN on the 23rd, experts suggest that the impact of volcanic eruptions on climate may be minimal. Greg Huey, Chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, stated that daily weather conditions near Mount Ruang, such as temperature, cloud cover, and rainfall, may not be significantly affected in the long term by the volcano.
Mount Ruang, a 2400-foot (725 meters) tall cone volcano located on Ruang Island in North Sulawesi Province, Indonesia, is prone to accumulating gases that can lead to explosive eruptions, as noted by volcanologists in the country.
Huey explained to CNN that the solid fragments within volcanic ash, such as rocks and minerals, collide and generate a significant amount of static electricity in the air, producing intense lightning. He stated that dense volcanic ash near the surface can degrade air quality and block sunlight, resulting in temporary cooling effects. Once an active eruption ceases, the volcanic ash begins to settle.
The gases released by the eruption of Mount Ruang penetrate beyond the troposphere (the lowest layer of the Earth’s atmosphere in which weather and climate phenomena occur) into the stratosphere (the second layer of the atmosphere). Huey elaborated that the stratosphere is a very dry region where only long-lived gases, lasting for several decades, typically penetrate. Volcanic eruptions transport short-lived gases like sulfur dioxide and water vapor into the stratosphere.
Information from the US National Center for Atmospheric Research (UCAR) shows that once in the stratosphere, sulfur dioxide and water vapor combine to form aerosols. These aerosols can linger in the stratosphere for up to three years, reflecting sunlight back into space and leading to a global cooling of temperatures.
Satellite instruments estimate that Mount Ruang has released approximately 300,000 tons of sulfur dioxide so far, although it is currently unclear how much volcanic gas has entered the stratosphere. Huey noted that this amount is significant but far from the most extreme scenarios.
In 1991, the eruption of the cone-shaped Pinatubo volcano in the Philippines resulted in the largest sulfur dioxide cloud in history. According to data from the US Geological Survey, the eruption released over 17 million tons of sulfur dioxide into the atmosphere, causing a global temperature decrease of about 0.5 degrees Celsius (0.9 degrees Fahrenheit) for about a year.