This study aims to quantify the potential impact of global climate change on Ireland's marine resource, which is of significant economic and social importance. Global climate models predict warming of the Earth's atmosphere and oceans, which will consequently affect mean sea levels, the frequency and severity of extreme weather events, winds and ocean waves. Such changes need to be carefully assessed for long‐term marine and coastal planning. We derived future wave climate projections for Ireland using the EC‐Earth global climate model and the WAVEWATCH III wave model, by comparing the future 30‐year period 2070–2099 to 1980–2009 for the RCP4.5 and the RCP8.5 forcing scenarios. This data set is currently the highest resolution wave projection data set available for Ireland. EC‐Earth predicts decreases in means (up to 3%) and extremes (up to 14% for the 95th percentile) of 10 m wind speeds over the North Atlantic Ocean (5–75°N, 0–80°W) by the end of the century. Similarly, the model projections show decreases in the frequency and intensity of wind storms crossing Ireland but these changes are not statistically significant. The WAVEWATCH III model predicts an overall decrease in mean (up to 15%) and extreme (up to 15% for the 95th percentile) annual, boreal winter and summer significant wave heights around Ireland.

Ireland has a highly energetic wave and wind climate, and is therefore uniquely placed in terms of its ocean renewable energy resource. The socio-economic importance of the marine resource to Ireland makes it critical to quantify how the wave and wind climate may change in the future due to global climate change. Projected changes in winds, ocean waves and the frequency and severity of extreme weather events should be carefully assessed for long-term marine and coastal planning. We derived an ensemble of future wave climate projections for Ireland using the EC-Earth global climate model and the WAVEWATCH III^® wave model, by comparing the future 30-year period 2070–2099 to the period 1980–2009 for the RCP4.5 and the RCP8.5 forcing scenarios. This dataset is currently the highest resolution wave projection dataset available for Ireland. The EC-Earth ensemble predicts decreases in mean (up to 2 % for RCP4.5 and up to 3.5 % for RCP8.5) 10 m wind speeds over the North Atlantic Ocean (5–75° N, 0–80° W) by the end of the century, which will consequently affect swell generation for the Irish wave climate. The WAVEWATCH III^® model predicts an overall decrease in annual and seasonal mean significant wave heights around Ireland, with the largest decreases in summer (up to 15 %) and winter (up to 10 %) for RCP8.5. Projected decreases in mean significant wave heights for spring and autumn were found to be small for both forcing scenarios (less than 5 %), with no significant decrease found for RCP4.5 off the west coast in those seasons.

The western coast of Ireland possesses one of the highest wave energy resources in the world and consequently is a promising location for the future deployment of Wave Energy Converters (WECs). Most wave climate studies for this region have focused primarily on the offshore area since it enjoys higher energy densities. However, recent studies have shown that nearshore locations offer a similar potential for the exploitation of wave energy as offshore sites [13]. Furthermore, the proximity of WEC devices to the shore will likely reduce losses in power transport, and facilitate access for maintenance activities. In this context, we analyse the wave climate over a ten year period for several nearshore sites off the Irish West Coast. The wave climate is estimated using a spectral wave model, WaveWatch III, forced with wind and spectral wave data from the ECMWF (European Centre for Medium Range Weather Forecast) operational archive. The wave model is validated with wave buoy data from intermediate to shallow depths (< 60 m). Our focus is on two aspects of the wave climate resource assessment. Firstly, we characterise the directionality of the wave energy resource (mean direction, directional spread) which affects the site selection, design and performance of nearshore WECs. Secondly, we discuss the climate data from the perspective of accessibility for maintenance. When selecting sites for the deployment of WECs, a balance needs to be found between two opposing criteria: the existence of sufficiently long, continuous time intervals of calm sea states (weather windows) which are necessary for maintenance activities to take place, and a high, consistent level of wave energy density, essential for economically viable wave energy extraction.

The Marine Institute of Ireland operates a network of weather buoys around Ireland. A wave of 32.3 m height (crest–trough) was recorded by one of these buoys, the M6 buoy, off the coast of Ireland in October 2020. In this paper, the technological evolution of this network is explored, with a particular emphasis on this extremely high wave. Raw data and bulk parameters collected during the event are presented, and the wider met-ocean context is outlined. In addition, wave data across the buoy deployment period from dual wave sensors installed on the buoy are analysed. Differences in calculation methods are discussed, rogue incidence rates are calculated, and the sensors are found to be generally in good agreement for key sea state parameters. Considerations specific to this network of buoys are described, including recent advances in technology that may affect continuity of historic records. Wave data from the buoys are found to be robust; the importance of keeping technological changes in mind and using the full raw dataset for analysis purposes are highlighted.