Climate Trivia: Substance in the Stratosphere
The 1991 eruption of Mt. Pinatubo injected into the atmosphere about 20 million tons of a certain substance, which blocked the incoming sunlight causing a global cooling of one degree Fahrenheit over 18 months.
Trivia Question: What was this substance?
a. Carbon dioxide (CO2)
b. Carbon monoxide (CO)
c. Sulfur dioxide (SO2)
d. Ash
The correct answer is c. The June 15th eruption of Mt. Pinatubo on the island of Luzon in the Philippines injected about 20 million tons of sulfur dioxide into the stratosphere, the second lowest layer of the atmosphere between six and 31 miles in altitude. The U.S. Environmental Protection Agency lists sulfur dioxide as a criteria air pollutant. When it is present in the lower parts of the atmosphere, it makes rain more acidic and can lead to damaged plants, buildings and degraded water quality. After the Pinatubo eruption, plumes of sulfur dioxide circled the Earth in about three weeks and by the end of the year had made it to the poles, forming a “sulfur dioxide envelope” around the Earth. The sulfur dioxide particles in the stratosphere absorbed sunlight, warming that layer of the atmosphere by seven degrees Fahrenheit, but they also prevented the usual amount of sunlight from reaching the Earth’s surface, which caused a surface cooling of one degree Fahrenheit.
Seasons: Winter, Spring, Summer, Fall
Sources: Gu, Lianhong et al. “Response of a Deciduous Forest to the Mount Pinatubo Eruption: Enhanced Photosynthesis.” Science 299 (2003): 2035-2038 and Wolfe, Jason. “Volcanoes and Climate Change.” NASA Earth Observatory 5 September 2000. 16 July 2008
