Publication Abstracts
McGraw et al. 2024
, , L. Polvani, , , and , 2024: Severe global cooling after volcanic super-eruptions? The answer hinges on unknown aerosol size. J. Climate, 37, no. 4, 1449-1464, doi:10.1175/JCLI-D-23-0116.1.
Volcanic super-eruptions have been theorized to cause severe global cooling, with the 74 kya Toba eruption purported to have driven humanity to near-extinction. However, this eruption left little physical evidence of its severity and models diverge greatly on the magnitude of post-eruption cooling. A key factor controlling the super-eruption climate response is the size of volcanic sulfate aerosol, a quantity that left no physical record and is poorly constrained by models. Here we show that this knowledge gap severely limits confidence in model-based estimates of supervolcanic cooling, and accounts for much of the disagreement among prior studies. By simulating super-eruptions over a range of aerosol sizes, we obtain global mean responses varying from extreme cooling all the way to the previously unexplored scenario of widespread warming. We also use an interactive aerosol model to evaluate the scaling between injected sulfur mass and aerosol size. Combining our model results with the available paleoclimate constraints applicable to large eruptions, we estimate that global volcanic cooling is unlikely to exceed 1.5°C no matter how massive the stratospheric injection. Super-eruptions, we conclude, may be incapable of altering global temperatures substantially more than the largest Common Era eruptions. This lack of exceptional cooling could explain why no single super-eruption event has resulted in firm evidence of widespread catastrophe for humans or ecosystems.
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BibTeX Citation
@article{mc00300e, author={McGraw, Z. and DallaSanta, K. and Polvani, L. and Tsigaridis, K. and Orbe, C. and Bauer, S. E.}, title={Severe global cooling after volcanic super-eruptions? The answer hinges on unknown aerosol size}, year={2024}, journal={Journal of Climate}, volume={37}, number={4}, pages={1449--1464}, doi={10.1175/JCLI-D-23-0116.1}, }
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RIS Citation
TY - JOUR ID - mc00300e AU - McGraw, Z. AU - DallaSanta, K. AU - Polvani, L. AU - Tsigaridis, K. AU - Orbe, C. AU - Bauer, S. E. PY - 2024 TI - Severe global cooling after volcanic super-eruptions? The answer hinges on unknown aerosol size JA - J. Climate JO - Journal of Climate VL - 37 IS - 4 SP - 1449 EP - 1464 DO - 10.1175/JCLI-D-23-0116.1 ER -
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