Coastal erosion is a "mega-sized problem" that must be tackled by re-engineering Irish society to "retreat from the shoreline," a conference on geological hazards has been told.
Among the measures the Government should consider for dealing with the issue is a buy-out of properties in areas threatened by coastal erosion, according to Prof Julian Orford of the School of Geography at Queen's University, Belfast.
Prof Orford told the conference in Dublin yesterday that Ireland had a history of defending its coastline in a piecemeal fashion. Future problems had also been hastened by an over-reliance of built responses, such as concrete bulwarks and barriers.
"Mitigation of erosion through engineered coastal defences is proving now to be short-term in success. These measures are generally expensive, unsustainable and provide insufficient benefit for society to be regarded as the best response to coastal erosion for future decades, especially given accelerated rates of coastal retreat," he told the conference organised by the Institute of Geologists of Ireland.
Planning was also piecemeal, he said, with responsibility for coastal zones divided between a web of overlapping authorities.
According to Prof Orford, the shoreline constantly adjusts its structure to coastal "forcing" through changes in sea level, tidal range and sediment supply.
Climate change was leading to higher sea levels, which were increasing by up to 2 mm a year along parts of the southern coast. While these amounts seemed small, they had major effects, including accelerated erosion and more frequent extreme weather events such as severe storms.
Coastal erosion was only a problem where humans were involved, but in Ireland the lack of proximity between society and shorelines up to the 20th century saved our society from the level of coastal hazard experienced elsewhere.
The economic growth of the late 20th century had generated a further phase of coastal development, including second homes and retirement properties, had further increased the tension between a static human infrastructure based on shorelines that were constantly shifting, Prof Orford explained.
"Adaptation should recognise that we cannot build our way out of trouble and that holding the line by way of coastal defences should only be considered for highly-valued societal functions; otherwise, retreat from the shoreline needs to be the governing principle for future adaptation."
Prof Orford said that retreat or set-back from the coast should be the main option for tackling coastal erosion by the year 2020.
According to Mr Tom Bolger of the Office of Public Works, flooding was a natural phenomenon frequently attributed to climate change.
Inappropriate development was often as much a contributory fact where this occurred.
