Sea levels around Ireland are rising at their fastest rate in at least 100 years, with the pace of increase accelerating significantly since 2000, according to new research led by Maynooth University.

The study, which reconstructs a century of sea-level change between 1925 and 2024, provides the most comprehensive assessment yet of long-term changes around the Irish coast.

Researchers at the university’s ICARUS Climate Research Centre combined tide-gauge measurements from six locations, including newly digitised historical records from Cork, Tarbert in Co Kerry and Galway.

The findings show that the current rate of sea-level rise is several times higher than the average recorded during most of the 20th century, reflecting the wider global acceleration associated with man-made climate change.

The research, published in the scientific journal Ocean Science under the title A Century of Sea-Level Change in Ireland (1925–2024), also highlights significant differences in the rate of change between locations.

Between 1925 and 2024, Belfast recorded the lowest long-term modelled rate of sea-level rise, while Tarbert in Co Kerry recorded the highest.

The differences reflect the influence of local and regional factors, including vertical land movement, environmental conditions and measurement effects.

Researchers also compared the Irish records with global sea-level datasets, finding that measurements around Ireland have followed the upward trajectory of global sea levels since the 1990s.

The study’s century-long perspective was made possible by the digitisation of historical observations that had previously been preserved in paper records. This allowed researchers to examine changes over a much longer period than was possible using existing modern tide-gauge data.

Dr Patrick McLoughlin, lead author and postdoctoral researcher at Maynooth University’s ICARUS Climate Research Centre, said the findings showed that the rate of sea-level rise experienced today was markedly different from the average across most of the previous century.

“This century-long record gives us a much clearer picture of how sea level around Ireland has changed over time,” he said.

“The key finding is that the rate we are seeing today is very different from the average rate across most of the twentieth century. Sea level is rising faster, and understanding that acceleration, including its local variations, is crucial for planning for future coastal change.”

Dr Gerard McCarthy, associate professor and principal investigator for the sea-level research at Maynooth University, said the study was the culmination of a decade of research.

“For many years, Irish sea level records were too short to conclusively show sea level rise here,” he said.

“The study is the culmination of 10 years of sea level research in Ireland, building on data from the National Tide Gauge Network and extending to the past century using painstaking data archaeology.”

He said the research demonstrated that climate change-driven sea-level rise was increasingly affecting Ireland.

Dr Glenn Nolan, director of Marine Environment and Food Safety Services at the Marine Institute, said the findings highlighted the importance of long-term ocean observation programmes and advanced analysis in informing climate adaptation policy.

The research involved scientists from the University of Limerick, University College Cork and Trinity College Dublin, alongside Maynooth University.

The findings have implications for coastal communities, infrastructure providers and planning authorities, particularly as they assess future flood risks, coastal erosion and the resilience of vulnerable areas.

Researchers said understanding both the acceleration in sea-level rise and the differences between individual locations would be important in preparing for future changes along Ireland’s coastline.