Future Changes in Significant Wave Height along Major Shipping Routes in East Asia using CORDEX-EA data

Climate change is expected to alter wave conditions across the world’s oceans, potentially affecting ship navigation safety and maritime transportation efficiency. In East Asia, where international shipping routes are highly concentrated, understanding future changes in wave climate is particularly important for assessing climate-related maritime risks. In this study, future changes in significant wave height (Hs) along major shipping routes in East Asia are investigated using regional climate projections from the CORDEX framework. Significant wave height data for a historical reference period and future climate scenarios were analyzed to examine changes in annual and seasonal mean conditions as well as high-wave occurrences. The analysis focuses on route-based characteristics by extracting Hs along representative major shipping corridors, allowing spatial variations in wave conditions to be evaluated from an operational maritime perspective. Changes in the frequency of high-wave conditions exceeding selected Hs thresholds were also assessed to identify potential increases in navigational risk. The results indicate that future changes in significant wave height exhibit pronounced spatial and seasonal variability across East Asian seas. While mean Hs changes are modest in some regions, several shipping route segments show an increase in high-wave occurrences, particularly during winter seasons. These changes suggest that climate-driven modifications of wave conditions may lead to increased operational challenges along specific routes, even in the absence of large changes in mean wave height. This study highlights the importance of route-oriented wave climate assessments for maritime applications and demonstrates the usefulness of CORDEX regional climate projections for evaluating future wave-related risks. The findings provide a basis for climate adaptation strategies in maritime transportation, including route planning and risk management under future climate conditions.