Early humans escaped worst impacts of massive volcanic eruption
Scientists use NCAR-based climate model to simulate the Toba volcano
Jul 9, 2021 - by Staff
A massive volcanic eruption in Indonesia about 74,000 years ago likely caused severe climate disruption in many areas of the globe, but the uneven climatic impacts meant that early human populations were sheltered from the worst effects.
A new study, led by Rutgers University with co-authors from the National Center for Atmospheric Research (NCAR), focused on the eruption of the Toba volcano — the largest volcanic eruption in the past two million years. Learning about its impacts is important for understanding environmental changes during a key interval in human evolution.
The researchers turned to the NCAR-based Community Earth System Model, analyzing 42 global climate model simulations in which they varied the magnitude of sulfur emissions, the time of year of the eruption, the background climate state, and the height reached by the volcanic plume. This enabled them to make a probabilistic assessment of climate impacts, showing that the eruption most likely disrupted climate in Asia and North America but had a far more muted impact in areas of human development in Africa.
“By using a probabilistic approach, we could determine the likelihood that some regions were less impacted by Toba, considering the wide range of estimates of its size and timing, in addition to our lack of knowledge of the underlying climate state,” said Jean-François Lamarque, a study co-author and director of NCAR’s Climate and Global Dynamics Laboratory. “Although a major volcanic eruption can cool the planet on average, you can experience very different effects depending on where you are.”
The study also provided the research team with an opportunity to test the fidelity of the Community Earth System Model by simulating a major, real-world event with massive climate consequences. Such research can help scientists understand the range of regional and global environmental impacts from past and future supervolcano eruptions.
The study appears in the Proceedings of the National Academy of Sciences. For more, see the Rutgers news release.