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Global-scale changes to extreme ocean wave events due to anthropogenic warming

July 16, 2021

Extreme surface ocean waves are often primary drivers of coastal flooding and erosion over various time scales. Hence, understanding future changes in extreme wave events owing to global warming is of socio-economic and environmental significance. However, our current knowledge of potential changes in high-frequency (defined here as having return periods of less than 1 year) extreme wave events are largely unknown, despite being strongly linked to coastal hazards across time scales relevant to coastal management. Here, we present global climate-modeling evidence, based on the most comprehensive multi-method, multi-model wave ensemble, of projected changes in a core set of extreme wave indices describing high-frequency, extra-tropical storm-driven waves. We find changes in high-frequency extreme wave events of up to ∼50%–100% under RCP8.5 high-emission scenario; which is nearly double the expected changes for RCP4.5 scenario, when globally integrated. The projected changes exhibit strong inter-hemispheric asymmetry, with strong increases in extreme wave activity across the tropics and high latitudes of the Southern Hemisphere region, and a widespread decrease across most of the Northern Hemisphere. We find that the patterns of projected increase across these extreme wave events over the Southern Hemisphere region resemble their historical response to the positive anomaly of the Southern Annular Mode. Our findings highlight that many countries with low-adaptive capacity are likely to face increasing exposure to much more frequent extreme wave events in the future.

Publication Year 2021
Title Global-scale changes to extreme ocean wave events due to anthropogenic warming
DOI 10.1088/1748-9326/ac1013
Authors Joao Morim, Sean Vitousek, Mark Hemer, Borja Reguero, Li H. Erikson, Merce Casas-Prat, Xiaolan L. Wang, Alvaro Semedo, Nobuhito Mori, Tomoya Shimura, Lorenzo Mentaschi, Ben Timmerman
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Research Letters
Index ID 70223280
Record Source USGS Publications Warehouse
USGS Organization Pacific Coastal and Marine Science Center