Transitional wave climate regions on continental and polar coasts in a warming world

Abstract

Wave climate is a primary driver of coastal risk, yet how climate change is altering wave climate is not fully understood. Here we identify transitional wave climate regions, coastlines with a future change in the occurrence frequency of a wave climate, with most of the regions located in south-western and eastern ocean basins. Analysis of the spatio-temporal changes in the atmosphere-driven major wave climates (the easterlies, southerlies and westerlies) under 2 emission scenarios for 2075–2099 and 2081–2099 shows increases in frequency from 5 to 20% for the easterly and southerly wave climates. The projected changes in these regions, in addition to sea-level rise and changes in storminess, can modify the general patterns of the prevailing wave climates and severely alter their coastal risks. Consequently, transitional wave climate regions should be recognized as areas of high coastal climate risk that require focus for adaptation in the near term. Changes in wave climate can pose substantial risk to coastal areas. Here transitional wave climate regions—areas where a wave climate will increase its frequency of occurrence—are identified and classified with implications for understanding future coastal risk.