The ash and lava from the Taal Volcano in the Philippines is spewing tons of gases into the air.
One of those gases is sulfur dioxide, which can have harmful effects on humans, animals and plants. In large enough quantities, sulfur dioxide can affect the Earth’s climate.
On Monday, the Philippine Institute of Volcanology and Seismology measured sulfur dioxide emissions at an average of 6,500 tons a day.
NASA released a satellite image Tuesday that showed concentrations of SO2 in the stratosphere spreading as far north as Japan.
In people, SO2 irritates skin and the tissues and mucous membranes of the eyes, nose and throat. High concentrations can cause lung inflammation and make breathing difficult.
In the air, SO2 can react with other compounds to form small particles that penetrate deeply into the lungs and in sufficient quantity can contribute to health problems, according to the U.S. Environmental Protection Agency.
Gaseous SO2 can harm trees and plants, and it can fall as acid rain.
Volcanoes also pump sulfur dioxide into the stratosphere, the second layer of Earth’s atmosphere that begins about 6 miles above the ground. In the stratosphere, SO2 converts to sulfuric acid, which condenses rapidly to form fine sulfate aerosols, according to the U.S. Geological Survey. The aerosols reflect the sun’s rays back into space, cooling the Earth’s lower atmosphere.
Several huge volcanic eruptions have caused a decline in the average temperature at the Earth’s surface.
In 1991, another Philippines volcano eruption caused global temperatures to drop by about 1 degree for two years.
Mount Pinatubo, about 90 miles northwest of Taal, pumped nearly 20 million tons of sulfur dioxide into the stratosphere when it erupted on June 15 that year, according to the USGS.
For the time being, Taal Volcano has not come close to reaching the SO2 levels released by Pinatubo.
However, officials with the volcano institute, warn that the eruption of lava on Tuesday and continued earthquakes possibly signal a larger eruption.