Dr. Matthew Toohey (Ph.D.) of the University of Saskatchewan (USask) and Dr. Michael Sigl (Ph.D.) of the University of Bern were part of the research team that developed an updated, more accurate reconstruction of volcanic eruptions that can help scientists understand future climate risks.
When volcanoes erupt, they spew much more than a spectacular, photogenic lava spray into the air. In fact, gases such as sulphur and carbon released into the atmosphere by volcanoes can have an impact on global climate. An international research team used cutting-edge technology to understand better historical volcanic eruptions and how they influenced climate change and radiation transmission in the atmosphere.
Determining how volcanic eruptions have contributed to climate change over time has traditionally relied on geochemical records extracted from Greenland’s polar ice sheet, which can be inconsistent or inaccurate due to its coarse resolution and limited scope. By synchronising ice core records from Greenland with new, high-resolution records from Antarctica, this study was able to improve the understanding of volcanic activity. The resulting record spans the last 11,500 years, during the Holocene, a period of relatively warm and stable climate that began after the last ice age.
“This new data set will enable scientists to address fundamental questions in climate science, such as how sensitive the climate system is to external forcing agents like volcanoes,” said Toohey, an assistant professor of physics and engineering physics in the College of Arts and Science and a member of the Institute of Space and Atmospheric Studies at USask. “A better understanding of past climate changes and their causes helps to improve climate models and future climate change projections.”
The researchers reconstructed a series of volcanic eruptions over the last 11,500 years using sophisticated computer modeling technology. The work included estimating the precise ages and amounts of atmospheric sulphur injections for over 850 historical volcanic eruptions for the first time by measuring the sulphur content of ice cores.
“A total of 26 eruptions over the last 11,500 years released more sulphur into the stratosphere than the colossal Tambora eruption in 1815, implying that eruptions of this size occur more than twice as frequently globally as previously thought,” said Sigl, who led the research project.
Sigl also stated that the study discovered a link between melting glaciers and an increase in volcanic activity, which helps scientists predict the potential effects of continued global warming on the climate. The findings were recently published in the journal Earth System Science Data.
Toohey was in charge of calculating the amount of sulphate in ice and calculating how stratospheric aerosols from previous eruptions affected the transmission of radiation through the atmosphere. Toohey and his colleagues’ tools will allow ice core data to be used in Holocene climate model simulations, as well as provide rapid estimates of the impact of potential future eruptions.
“This work significantly improves our ability to estimate the likelihood of large, climate-relevant eruptions in the future, as well as their radiative impact, providing a valuable resource for climate risk assessment,” Toohey said.