Climate change, impacts and vulnerability in Europe ... - MemoFin.fr

Climate impacts on environmental systems3.2.4 Coastal erosionRelevanceCoastal erosion is the process of wearing awaymaterial from a coastal profile due to imbalance inthe supply and export of material from a certainsection. It takes place in the form of scouring inthe foot of the cliffs or dunes or at the sub-tidalforeshore. Coastal erosion takes place mainly duringstrong winds, high waves and high tides and stormsurge conditions, and results in coastline retreat andloss of land (Mangor, 2001).More than 5 million people in Europe are livingin areas at risk from coastal erosion and marineflooding (defined as being below 5 m elevation,but not further than 1 km distance from thecoastline) ( 42 ). The increasing human use of thecoastal zone has turned coastal erosion from anatural phenomenon into a problem of growingimportance for societies. Adverse impacts of coastalerosion most frequently encountered in Europe canbe grouped in three categories: 1) coastal flooding asa result of complete dune erosion, 2) underminingof sea defences associated with foreshore erosionand coastal squeeze, and 3) retreating cliffs, beachesand dunes causing loss of lands of economic andecological value (Conscience, 2010).Coastal erosion in Europe causes significanteconomic loss, ecological damage and societalproblems. Loss of property, residential andcommercial buildings, infrastructure, beach width,and valuable coastal habitat causes millions of eurosworth of economic damage each year and presentssignificant management issues. At the same timeprotection is expensive. For example, in France someEUR 20 million is spent each year on mitigationmeasures and in the Netherlands the annualbudget for sand nourishment amounts to someEUR 41 million (Marchand, 2010).Past trendsMany European coasts are endangered because theyare being affected by coastal erosion. Accordingto the Eurosion Project ( 43 ) (Eurosion, 2004),about 20 000 km of coasts faced serious impactsin 2004. Most of the impact zones (15 100 km) areactively retreating, some of them in spite of coastalprotection works (2 900 km). In addition, another4 700 km have become artificially stabilised.Figure 3.8 shows the pattern of erosion and accretionin Europe, including statistics for all Europeanseas. The largest percentage of eroding coasts isfound along the Mediterranean and North Seas. TheBaltic Sea is the only sea where the proportion ofaccumulative coasts is larger than that of erodingcoasts, mostly due to the isostatic land uplift in thenorthern parts of the Baltic. In total, ca. 15 % of theEuropean coastline was eroding, and about the samelength was accreting (almost exclusively in northernEurope); 40 % was stable, and data was missing forthe remaining 30 %. Other climate change driversthat may exacerbate erosion rates are increasedstorminess, higher waves and changes in prevalentwind and wave directions.Key messages: 3.2.4 Coastal erosion• Coastal erosion in Europe causes significant economic loss, ecological damage and societal problems.About one quarter of the European coastline for which data is available is currently eroding.• Projections for coastal erosion are not available. Future climate change, in particular rising sea levels, isexpected to accelerate coastal erosion.( 42 ) Calculation by EEA, based on the 2001 population census.( 43 ) See http://www.eurosion.org.110 Climate change, impacts and vulnerability in Europe 2012