Climate Projections Very Likely Underestimate Future Volcanic Forcing and Its Climatic Effects

Chim, Man Mei; Aubry, Thomas J.; Abraham, Nathan Luke; Marshall, Lauren; Mulcahy, Jane; Walton, Jeremy; Schmidt, Anja

Abstract

Standard climate projections represent future volcanic eruptions by a constant forcing inferred from 1850 to 2014 volcanic forcing. Using the latest ice-core and satellite records to design stochastic eruption scenarios, we show that there is a 95% probability that explosive eruptions could emit more sulfur dioxide (SO2) into the stratosphere over 2015–2100 than current standard climate projections (i.e., ScenarioMIP). Our simulations using the UK Earth System Model with interactive stratospheric aerosols show that for a median future eruption scenario, the 2015–2100 average global-mean stratospheric aerosol optical depth (SAOD) is double that used in ScenarioMIP, with small-magnitude eruptions (<3 Tg of SO2) contributing 50% to SAOD perturbations. We show that volcanic effects on large-scale climate indicators, including global surface temperature, sea level and sea ice extent, are underestimated in ScenarioMIP because current climate projections do not fully account for the recurrent frequency of volcanic eruptions of different magnitudes.

Citation

Chim, M. M., Aubry, T. J., Abraham, N. L., Marshall, L., Mulcahy, J., Walton, J., & Schmidt, A. (2023). Climate Projections Very Likely Underestimate Future Volcanic Forcing and Its Climatic Effects. Geophysical Research Letters, 50(12), Article e2023GL103743. https://doi.org/10.1029/2023gl103743

• Journal Article Type: Article
• Acceptance Date: Jun 3, 2023
• Online Publication Date: Jun 13, 2023
• Publication Date: Jun 28, 2023
• Deposit Date: Nov 2, 2023
• Publicly Available Date: Nov 2, 2023
• Journal: Geophysical Research Letters
• Print ISSN: 0094-8276
• Electronic ISSN: 1944-8007
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 50
• Issue: 12
• Article Number: e2023GL103743
• DOI: https://doi.org/10.1029/2023gl103743
• Public URL: https://durham-repository.worktribe.com/output/1875612