At the Rock of Cashel, climate change threatens the past – and the future
Climate change represents the single greatest threat to heritage sites like the Rock of Cashel.
That’s according to Terri Sweeny Meade, the Office of Public Works (OPW) assistant principal architect with responsibility for conservation.
Ms Sweeny Meade said that a number of pieces of research had been done on the Rock of Cashel to understand how climate change might affect it. They are now being used to inform the OPW’s conservation efforts.
A 2024 study led by William Megarry from Queen’s University Belfast’s School of Natural and Built Environment highlighted a number of key threats posed to Ireland’s heritage sites, including the Rock of Cashel, by climate change.
“The study identified potential risks of soil erosion, structural damage and altered microbiological activity,” Ms Sweeney Meade said.
“These all affect our conservation efforts because, once you know that these are the hazards that you’re facing, you can start to work in tandem with each hazard and see are there inter-relationships between the different hazards and are they going to happen at different rates.”
The Rock of Cashel was the original seat of the high kings of Munster, including Brian Boru, who was crowned there in 978 before becoming high king of Ireland. It was granted to the Church in 1101, and is one of Ireland’s most important historical sites.
Conservation efforts first began on the Rock of Cashel in 1875, carried out by Thomas Newenham Deane.
Since then, conservation teams have continuously worked to preserve the monument, which is on the Unesco Tentative World Heritage Sites list.
Michele O’Dea, a senior architect in the OPW, was responsible for some “groundbreaking” works on how best to preserve the monument, Ms Sweeny Meade said.
“Michele wrote about the conservation works at Cormac’s Chapel in 2018, and that’s important because all of us who have worked on the monument since then are still keeping the same pieces of conservation work going,” she said.
Ms O’Dea’s work focused on rainfall penetrating the walls of Cormac’s Chapel and degrading its frescoes, which depict scenes from the early life of Christ and are believed to have been painted in the mid-12th century.
With increased rainfall predicted due to climate change, Ms Sweeny Meade said that carrying on conservation efforts such as these will help to protect the building into the future.
Another project that aims to protect the Rock of Cashel from increased rainfall levels is concealed guttering that collects rainwater and stops it from soaking into the ground and making the land that the buildings sit on unstable.
“They put in a rainwater gutter that is concealed, but it’s accessible. And the water is collected so it doesn’t go down into the rest of the site and weaken the foundations,” Ms Sweeny Meade said.
This project is something that can be built on if there are higher amounts of rainfall as a result of climate change, she added.
In the medium term, works to protect the building’s south gable are due to get under way shortly. Old mortar will be removed and any cracks in the building’s gable will be repaired to ensure that rain doesn’t find its way into the old stone building and make it unstable, ensuring it remains intact for future generations to enjoy.