The researchers reconstructed sea level measurements from six locations around the Irish coast, Belfast, Malin Head, Dublin Port, Cork, Galway and Tarbert in the Shannon Estuary, by combining modern tide-gauge data with historical records, some recovered and digitised. This allowed them to extend the analysis back to 1925.
The study found that sea levels rose by just 1.3cm in the 50 years from 1925 to 1975, but by about 9cm in the 31 years from 1993 to 2024. By 2024, the annualised rate had reached an estimated 4.26mm. Overall, sea levels around Ireland have risen by almost 12cm since 1925. The acceleration is consistent with global patterns linked to human-induced climate change.
The rate of rise varied around the coast. Tarbert in Co Kerry recorded the highest long-term rate, followed by Galway; Cork and Malin Head had equal rates, followed by Dublin Port and Belfast. The differences are partly explained by the ongoing movement of the Earth's crust following the last Ice Age, with land in parts of the northeast still rising relative to other areas, while parts of the southwest experience less uplift or subsidence.
Dr Patrick McLoughlin, lead author and a postdoctoral researcher at Maynooth University's ICARUS Climate Research Centre, said the findings provide a much clearer picture of how sea levels around Ireland have changed. "The key finding is that the rate we are seeing today is very different from the average rate across most of the 20th century," he said. Dr Gerard McCarthy, an oceanographer and associate professor who led the wider sea-level research programme, said the findings represented the culmination of ten years of scientific work and described the process as painstaking data archaeology. He said the study shows that "climate change-driven sea-level rise is coming home to roost for Ireland." The researchers warn that continued increases will heighten the potential for coastal flooding and inundation, creating growing challenges for communities, infrastructure providers and planning authorities.