Global climate disruption and regional climate shelters after the Toba supereruption.

Autor:	Black BA; Earth and Atmospheric Science, City College of New York, New York, NY 10031; bblack@ccny.cuny.edu.; Earth and Environmental Sciences, Graduate Center, City University of New York, New York, NY 10017.; Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ 08854., Lamarque JF; Climate and Global Dynamics Lab, National Center for Atmospheric Research, Boulder, CO 80305., Marsh DR; Climate and Global Dynamics Lab, National Center for Atmospheric Research, Boulder, CO 80305.; Faculty of Engineering and Physical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom., Schmidt A; Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.; Department of Geography, University of Cambridge, Cambridge CB2 1BY, United Kingdom., Bardeen CG; Atmospheric Chemistry Observations and Modeling Lab, National Center for Atmospheric Research, Boulder, CO 80301.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Jul 20; Vol. 118 (29).
DOI:	10.1073/pnas.2013046118
Abstrakt:	The Toba eruption ∼74,000 y ago was the largest volcanic eruption since the start of the Pleistocene and represents an important test case for understanding the effects of large explosive eruptions on climate and ecosystems. However, the magnitude and repercussions of climatic changes driven by the eruption are strongly debated. High-resolution paleoclimate and archaeological records from Africa find little evidence for the disruption of climate or human activity in the wake of the eruption in contrast with a controversial link with a bottleneck in human evolution and climate model simulations predicting strong volcanic cooling for up to a decade after a Toba-scale eruption. Here, we use a large ensemble of high-resolution Community Earth System Model (CESM1.3) simulations to reconcile climate model predictions with paleoclimate records, accounting for uncertainties in the magnitude of Toba sulfur emissions with high and low emission scenarios. We find a near-zero probability of annual mean surface temperature anomalies exceeding 4 °C in most of Africa in contrast with near 100% probabilities of cooling this severe in Asia and North America for the high sulfur emission case. The likelihood of strong decreases in precipitation is low in most of Africa. Therefore, even Toba sulfur release at the upper range of plausible estimates remains consistent with the muted response in Africa indicated by paleoclimate proxies. Our results provide a probabilistic view of the uneven patterns of volcanic climate disruption during a crucial interval in human evolution, with implications for understanding the range of environmental impacts from past and future supereruptions. Competing Interests: The authors declare no competing interest.
Databáze:	MEDLINE
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