Volcanoes, Not Humans, Are Responsible for Increased Sulfur Dioxide in Stratosphere: A Study

Despite the fact that trace gases and aerosols are known to have a major influence on the environment, up until this point, the required data in order to account for them have been absent in computer models designed to calculate climate change.

For this reason, Kalsruhe Institute of Technology (KIT) scientist Michael Hopfner decided to set about researching the effects of, among other things, the reaction of sulfur dioxide and water vapor to sulfuric acid that, in turn, reflect solar radiation back into space.

In order to do so, Hopfner relied on the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) located on the European environmental satellite ENVISAT in order to collected data from 2013 to 2012, during which time the device recorded more than 75 million infrared spectra.

In doing so, Hopfner and his team made several realizations. Among them was the discovery that volcanoes, not humans, are responsible for significant concentrations of sulfur dioxide and thus an increase in stratospheric aerosol groupings.

For this reason, in addition to demonstrating that major eruptions such as those of the Pintuba in 1991 and Tambora in 1815 have had significant effects on the climate, the study illustrates how smaller eruptions even within the last decade have produced a measurable effect on sulfur dioxide concentration at altitutdes between 20 and 30 kilometers.

For this reason, Hopfner stated in a press release, human-related sources, such as power plants in Asia, can now be excluded as making a relevant contribution at such a height.

“The new measurement data help improve consideration of sulfur-containing substances in atmosphere models,” Höpfner explains. “This is also important for discussing the risks and opportunities of climate engineering in a scientifically serious manner.”

The study was published in the journal of Atmospheric Chemistry and Physics, an interactive and open access journal of the European Geosciences Union.