Changes in extreme ocean wave heights under 1.5 °C, 2 °C, and 3 °C global warming

• Published in: Weather and Climate Extremes
• Main Authors: Anindita Patra, Seung-Ki Min, Prashant Kumar, Xiaolan L. Wang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: Extreme waves; Paris agreement; CMIP5; Southern annular mode; El Niño–Southern oscillation; Meteorology. Climatology; QC851-999; Antarctic; Pacific; Antarc*; Ice Shelves
• Online Access: https://doi.org/10.1016/j.wace.2021.100358; https://doaj.org/article/89a7dd265a6641648cc7c0f48235a3cc

This study inspects the global changes in seasonal extreme ocean wave heights under different levels of global warming (1.5 °C, 2 °C, and 3 °C) based on statistical wave projections derived from CMIP5 multi-model simulations. The results show robust increases in wave extremes up to 15% (∼1 m) over Southern Hemisphere high latitudes and tropical Pacific, particularly at 3 °C warming. Strong seasonality is observed, especially for the North Pacific. Under higher warming, stronger increases are identified in both amplitude and area of extreme wave heights. The change in magnitude translates into shorter return intervals of extreme wave events in a warmer world, particularly at 3 °C warming. Differences between 1.5 °C and 2 °C worlds reveal potential benefits of limiting global warming over large regions of global ocean. Strong inter-model relationships indicate that wave height increases are associated with intensified climate mode variability, particularly the Southern Annular Mode and El Niño–Southern Oscillation, in a warmer world. An important implication is the potential impact of increased wave extremes on West Antarctic ice shelves with respect to calving and associated loss of buttressing, which would facilitate sea level rise in a warmer world.