Vulnerabilities

The effect of a sea level rise on estuaries will tend to enlarge their vertical and horizontal extent, resulting in the penetration of tides further upstream. The inland penetration of saltwater could also result in the contamination of low-lying coastal aquifers and other freshwater sources. Coastal aquifers, along with estuaries and wetlands, are also at risk due to saltwater intrusion (1).

Saltwater intrusion of groundwater will probably become more frequent during the summer under conditions of both reduced freshwater discharge and sea level rise. Salinisation of these aquifers is unlikely to extend more than 200 m further inland, and at present coastal aquifers are of little economic importance, reducing this impact of environmental change. But a continued expansion in coastal populations and industrial pressures on freshwater resources, as well as changing agricultural land uses at the coast, may create negative feedbacks to coastal resilience (2).

Salt water intrusion due to sea-level rise is mostly a very slow process that may take several centuries to reach equilibrium (3). Even small rates of groundwater pumping from coastal aquifers are expected to lead to stronger salinization of the groundwater than sea-level rise during the 21st century (4).

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Ireland.

1. Environmental Protection Agency (2003)
2. Devoy (2008)
3. Webb and Howard (2011), in: IPCC (2014)
4. Ferguson and Gleeson (2012); Loaiciga et al. (2012), both in: IPCC (2014)