Elevated atmospheric CO ₂ drove an increase in tropical cyclone intensity during the early Toarcian hyperthermal

Abstract

The occurrence of sedimentary storm deposits around the Tethys Ocean during the early Toarcian hyperthermal (~183 Ma) suggests that intensified tropical cyclone (TC) activity occurred in response to CO 2 rise and marked warming. However, this hypothesized linkage between extreme warmth and storm activity remains untested, and the spatial pattern of any changes in TCs is unclear. Here, model results show that there were two potential storm genesis centers over Tethys during the early Toarcian hyperthermal located around the northwestern and southeastern Tethys. The empirically determined doubling of CO 2 concentration that accompanied the early Toarcian hyperthermal (~500 to ~1,000 ppmv) leads to increased probability of stronger storms over Tethys, in tandem with more favorable conditions for coastal erosion. These results match well with the geological occurrence of storm deposits during the early Toarcian hyperthermal and confirm that increased TC intensity would have accompanied global warming.

Asymmetric and Irreversible Response of Tropical Cyclone Potential Intensity to CO2 Removal

“…In response to the very likely future warming, both theoretical and numerical modeling studies projected an enhancement of storm intensity (Knutson et al, 2020;Lee et al, 2020;Pérez-Alarcón et al, 2023;Wu et al, 2022), hence posing tremendous risks and impacts for the socioeconomic development and human lives (Peduzzi et al, 2012;Rappaport, 2000). Such projected stronger storms are supported by the evidence during the past warmer-than-present climates (Fedorov et al, 2010;Hearty & Tormey, 2017;Krencker et al, 2015;Yan et al, 2016Yan et al, , 2021Yan et al, , 2023, highlighting the intimate linkage between storm intensity and global warming.…”