1.1
Coastal zones
Key messages

Projected sea-level rise, possible changes in the frequency and intensity of storm surges and
the resulting coastal erosion are expected to have major impacts on low-lying coastal areas
across Europe.

Future global mean sea-level rise in the 21st century is likely to be greater than during the
20th century. It is more likely to be less than 1 m than to be more than 1 m.

Projections of changes in storms currently have high uncertainty. Increases in extreme coastal
water levels will likely be dominated by increases in local relative mean sea level rather than
by changes in storm activity in most locations.

Coastal erosion in Europe causes significant ecological damage, economic loss and other
societal problems. About one quarter of the European coastline for which data is available is
currently eroding.
1.1.1
Overview
Relevance
Coastal zones in Europe are centres of population and economic activity. They are inhabited by
diverse ecosystems, in particular wetland ecosystems. Projected climate change, including sea-level
rise and associated changes in frequency and/or intensity of storm surges and erosion, threaten human
and natural systems at the coasts in various ways. Management of the coastal zones needs to consider
the multiple functions of many coastal areas, which is increasingly occurring through integrated
coastal zone management. Adaptation policies also need to consider the full range of adaptation
options, including measures such as dike building, beach nourishment, rehabilitation of coastal
ecosystems, area-related measures, integrated coastal zone management, and elaboration and
distribution of flood hazard and flood risk maps for costal zones according to the Flood risk
management directive.
Selection of indicators
This section presents the following indicators on threats to the coastal zone that are sensitive to
climate change:

Global and European sea-level rise;

Storm surges.
The final section presents information on coastal erosion. This information is not presented as an EEA
indicator because regular updates of the underlying information base cannot be expected.
Another important risk in low-lying coastal regions is salt-water intrusion into freshwater reservoirs.
Salt-water intrusion can be caused by relative sea-level rise and by overexploitation of groundwater
resources. It can threaten freshwater supply, agriculture and ecosystems in coastal regions. However,
current data availability is insufficient for developing an indicator on salt-water intrusion. Information
on ecological impacts of climate change is not presented in this report due to a lack of data at
European scale. Further information on the economic and health risks associated with sea-level rise is
presented in Subsection Error! Reference source not found..
[Climate change, impacts, and vulnerability in Europe]
1
1.1.2
Global and European sea-level rise
Key messages

Tide gauges show that global mean sea level rose at a rate of around 1.7 mm/year over the 20th
century, but there has been significant decadal variations around this value.

Satellite measurements show a rate of global mean sea-level rise of around 3 mm/year over the
last 2 decades.

Sea level is not rising uniformly at all locations, with some locations experiencing much greater
than average rise.

Projections of global mean sea-level rise in the 21st century range between 20 cm and about 2 m.
Modelling uncertainty contributes at least as much to the overall uncertainty as uncertainty about
future GHG emissions scenarios. It is likely that 21st century sea-level rise will be greater than
during the 20th century. It is more likely to be less than 1 m than to be more than 1 m.

Coastal impacts also depend on the vertical movement of the land, which can either add to or
subtract from climate-induced sea-level change, depending on the particular location.
Relevance
Sea level is an important indicator of climate change because it is associated with significant potential
impacts on settlements, infrastructure, people and natural systems. It acts on time scales much longer
than those of indicators that are closely related to near-surface temperature change (see
Section Error! Reference source not found.). Even if GHG concentrations were stabilised
immediately, sea level would continue to rise for centuries.
Low-lying coastlines with high population densities and small tidal ranges are most vulnerable to sealevel rise, in particular where adaptation is hindered by a lack of economic resources or by other
constraints. In Europe, the potential impacts of sea-level rise include flooding, coastal erosion, and the
loss of flat coastal regions (EEA, 2010). Rising sea levels can also cause salt-water intrusion into lowlying aquifers and endanger coastal ecosystems and wetlands. Higher flood levels increase the risks to
life and property, including sea dikes and other infrastructure, with possible follow-up effects on
tourism, recreation and transportation functions. Damage associated with sea-level rise would
frequently result from extreme events, such as storm surges, the frequency of which would increase as
the mean sea level rises (see Subsection 1.1.3).
Changes in global average sea level result from a combination of several physical processes. Thermal
expansion of the oceans occurs as a result of warming ocean water. Additional water is added to the
ocean from a net melting of glaciers and small ice caps, and from the large Greenland and West
Antarctic ice sheets. Further contributions may come from changes in the storage of liquid water on
land, either in natural reservoirs such as groundwater or man-made reservoirs.
The locally experienced changes in sea level differ from global average changes for various reasons.
Changes in water density are not expected to be spatially uniform, and changes in ocean circulation
also have regionally different impacts. At any particular location there may also be a vertical
movement of the land in either direction, for example due to the post-glacial rebound (in northern
Europe) or to local groundwater extraction.
Past trends
Sea-level changes can be measured using tide gauges and remotely from space using altimeters. Many
tide gauge measurements have long multi-decade time series, with some exceeding more than 100
2
[Climate change, impacts, and vulnerability in Europe]
years. However, the results can be distorted by local effects. Satellite altimeters enable sea level to be
measured from space and give much better spatial coverage (except at high latitudes). However, the
length of the record is limited.
Figure Error! No text of specified style in document..1
level from 1860 to 2009
Note:
Change in global mean sea
Global mean sea level from 1860 to 2009 as estimated from coastal and island sea-level data (1880 –
2009, blue) and from satellite altimeter data (1993 – 2009, grey).
Source: (Church and White, 2011).
Rates of global mean sea-level (GMSL) rise have been estimated at approximately 3 mm/year since
around the mid-1990s (Church and White, 2011). This is greater than the longer term rise during the
20th century of around 1.7 mm/year, which is shown in Figure Error! No text of specified style in
document..1. There is evidence that the contribution from the melting cryosphere has increased
recently (Velicogna, 2009). Both for recent decades and over the longer term historical period, there is
some variability evident about the trend. In particular, there are periods during the 20th century before
the 1990s where the rate of sea-level rise may have reached the recent rate of 3 mm/year for some
years, although the higher rates of sea-level rise were generally sustained for shorter periods than
recently. For a very recent time period, the variability in sea level includes a notable dip, starting in
2010. It has been suggested, based on observations from the GRACE satellite, that this observed
recent dip in sea level may be related to the switch from El Niño to La Niña conditions in the Pacific
and associated changes in precipitation patterns and storage of water on land (NASA, 2012).
It is not yet clear from observations whether the generally increased rate of sea-level rise observed
since the mid-1990s will continue into the future. The many observations of surging outlet glaciers
and ice streams (which could lead to high future rates of sea-level rise) must be balanced by recent
work showing that some outlet glaciers on the Greenland ice sheet have now either stopped
accelerating or even slowed down (Joughin et al., 2010). Modelling work of individual ice sheet
glaciers also shows the potential for decadal and multi-decadal variability in glacier flow (Nick et al.,
2009). There is sufficient evidence, based on recent observations, to be concerned about the
possibility for an increase in the rate of sea-level rise to 2100 beyond that projected by the models
used in the IPCC AR4 (IPCC, 2007) (see Figure Error! No text of specified style in document..2).
However, a greater understanding of the potential for accelerated ice sheet dynamical processes that
[Climate change, impacts, and vulnerability in Europe]
3
could give rise to such rapid sea-level rise is needed from improved physically-based models and
from appropriate palaeo observations before more precise and reliable estimates of future sea-level
rise can be made.
Deviations in the rate of sea-level rise at individual locations are evident in both tide gauge and
satellite studies. Map Error! No text of specified style in document..1 shows the rates of change in
sea level since 1992 for the European region based on satellite observations. Trends in the North Sea
are typically around 2 mm/year, except for some parts of the southern-most North Sea where they are
larger. Parts of the English Channel and the Bay of Biscay show a small decrease in sea level over this
period. The Baltic Sea shows an increase of between around 2 mm/year and 5 mm/year. In the
Mediterranean Sea there are regions with increases of more than 6 mm/year, and with decreases of
more than - 4 mm/year. The Black Sea has seen an increase in sea level of between zero and around
5 mm/year.
Map Error! No text of specified style in document..1
Trend in absolute sea level
across Europe based on satellite measurements (1992–2011)
Source: Figure supplied by Michaël Ablain (produced at CLS/CNES/LEGOS group, also available through
MyOcean).
4
[Climate change, impacts, and vulnerability in Europe]
Map Error! No text of specified style in document..2
Trend in relative sea level at
selected European tide gauge stations (1900–2010)
Note:
These measured trends are not corrected for local land movement. No attempt has been made to
assess the validity of any individual fit, so results should not be treated as suitable for use in planning or
policymaking.
Source: (Woodworth and Player, 2003), Permanent Service for Mean Sea Level (PSMSL), 2012,
"Tide Gauge Data" (http://www.psmsl.org/products/trends/)
The reasons for these big differences, even within a particular sea or basin, are due to different
physical processes being the dominant cause of sea-level change at different locations. For instance,
the Mediterranean Sea is a semi-closed, very deep basin, exchanging water with the Atlantic Ocean
through the narrow Gibraltar Strait only. It is a concentration basin where evaporation greatly exceeds
precipitation and river run-off. Therefore, salinity is one of the main physical parameters influencing
the thermohaline circulation and sea-level variability in the Mediterranean, which may counteract the
thermal expansion due to a rise in temperature. The NAO, interannual wind variability, changes in
global ocean circulation patterns, and the location of large scale gyres are further factors that can
influence local sea level in the European seas.
Map Error! No text of specified style in document..2 shows observed trends in sea level from
selected tide gauge stations in Europe. These trends can differ from those measured by satellites (see
Map Error! No text of specified style in document..1) because of the different time periods covered
and because tide gauge measurements are influenced by vertical land movement whereas satellite
measurements are not. In particular, the lands around the northern Baltic Sea are still rising since the
last ice age due to the post-glacial rebound (Johansson et al., 2002).
A significant recent step forward in projecting future sea levels is an improved understanding of the
contributions to recent sea-level rise. A recent study found good agreement over the four last decades
between observed total global sea-level rise and the sum of known contributions (Church and White,
2011). Table Error! No text of specified style in document..1 summarises the main contributions
based on that study. According to this table, thermal expansion was likely to have been the most
important contributor to sea-level rise throughout the whole period (1972–2008). Sea-level rise has
[Climate change, impacts, and vulnerability in Europe]
5
accelerated in the latter part of that period (1993–2008) when the melting of glaciers and ice caps
became the most important source of sea-level rise.
Table Error! No text of specified style in document..1
budget since 1972
Contributions to the sea level
Component
1972 to 2008
Total from tide gauges
1.83 ± 0.18b
Total from tide gauges and
2.10 ± 0.16
altimeter
1. Thermal expansion
0.80 ± 0.15
2. Glaciers and ice caps
0.67 ± 0.03
3. Greenland ice sheet
0.12 ± 0.17
4. Antarctic ice sheet
0.30 ± 0.20
5. Terrestrial storage
- 0.11 ± 0.19
Sum of components
1.78 ± 0.36
(1.+2.+3.+4.+5.)
Note:
All values are stated in mm/yr.
1993 to 2008
2.61 ± 0.55
3.22 ± 0.41
0.88 ± 0.33
0.99 ± 0.04
0.31 ± 0.17
0.43 ± 0.20
- 0.08 ± 0.19
2.54 ± 0.46
Source: (Church and White, 2011)
Projections
Currently there are two main approaches to projecting future sea level: physically-based models that
represent the most important known processes, and statistical models that apply the observed
relationship between temperature or radiative forcing on the one hand and sea level on the other hand
in the past and extrapolate it to the future. Both approaches produce a spread of results, which results
in large uncertainties around future sea-level rise.
The IPCC AR4 contained several statements on future sea level. Most often quoted is the range of
sea-level rise projected by physically-based models for thermal expansion, glaciers and small ice
caps, the mass balance of the Greenland and West Antarctic ice sheet, and a term to represent the
observed dynamic acceleration of the melting of the major ice sheets. The result is a global average
increase of between 0.18 m and 0.59 m from the 1980–1999 mean to the 2090–2099 mean. The range
depends on both the spread in future GHG emissions and uncertainty from computer models. The
largest sea-level rise contribution was projected to come from the thermal expansion (0.10 to 0.41 m),
followed by melting of glaciers and ice caps (0.07 to 0.17 m) and Greenland ice sheet (0.01 to
0.12 m). The IPCC AR4 went further by including a simple sensitivity study, which allowed for
future linear increases in the dynamic ice sheet component with temperature. Whilst it is not clear that
such a relationship would be linear the calculations suggest an additional 17 cm of rise could occur
during the 21st century. The report acknowledged that limitations in understanding and models meant
that it was not possible to provide with any degree of confidence either a highest plausible 21st
century rise or central estimate of rise for all of the component sea-level terms.
Since publication of the IPCC AR4, further progress has been made in understanding and simulating
sea-level changes (Church and White, 2011). However, global physical models are still particularly
limited in their representation of ice sheet processes (Nicholls et al., 2010). Since current
understanding suggests that the potential for 21st century sea-level rise significantly above the AR4
range would largely result from potential increases in the ice sheet dynamical contributions, the lack
of suitable physically-based models is still a significant hindrance to making reliable projections.
Statistical models of sea-level rise are also available. These models use observed relationships
between changes in sea level and either surface air temperature or radiative forcing (Rahmstorf, 2007;
Vermeer and Rahmstorf, 2009). The statistical models are then combined with 21st century
projections of radiative forcing or temperature and used for projection purposes. Typically, they
produce larger sea-level rise projections than current physically-based models. Future projections
based on this approach have limitations because the balance of contributions to sea-level rise during
the future may not be the same as the balance during the tuning period of these statistical relationships
6
[Climate change, impacts, and vulnerability in Europe]
(Lowe and Gregory, 2010). However, the differences between the two modelling approaches may also
be interpreted as indicating the scale of processes not well represented in physically-based models.
In view of these limitations to future projections purely from models, some studies have combined
understanding from current physical models with other strands of evidence to provide information on
possible high-end sea-level rise amounts. Evidence stands include maximum rates of sea-level rise at
the last interglacial and plausible kinematic constraints on future ice flows. A synthesis of high-end
sea-level rise estimates based on all sources of information available is provided in Figure Error! No
text of specified style in document..2.
Figure Error! No text of specified style in document..2
Range of high-end estimates of
global sea-level rise published after the IPCC AR4
Note:
Range of high-end global sea-level rise (metre per century) estimates published after the IPCC Fourth
Assessment Report (AR4). AR4 results are shown for comparison in the three left-most columns.
Source: (Nicholls et al., 2010).
The major conclusion from recent studies is that it is still not possible to rule out GMSL increases
during the next century of up to approximately 2 m. However, the balance of evidence suggests
increases significantly in excess of 1 m are still considered much less likely than lower rates of sealevel rise. This is consistent with the results of the Thames Estuary 2100 study in the UK (Lowe et al.,
2009) and a recent study in the Netherlands (Katsman et al., 2011). The latter, for example, combined
modelling and expert judgement to derive a plausible high-end global scenario of 21st century sealevel rise of 0.55 to 1.15 m. However, they again concluded that although the probability of larger
increases is small, it was still not possible to rule out increases approaching around 2 m based on
palaeo-climatic evidence (Rohling et al., 2008). In summary, the highest projections available in the
scientific literature should not be treated as likely increases in 21st century sea level, but they are
useful for vulnerability tests against flooding in regions where there is a large risk aversion to
flooding, or the consequences of flooding are particularly catastrophic.
Specific projections for regional seas
[Climate change, impacts, and vulnerability in Europe]
7
Future projections of the spatial pattern of sea-level rise also remain highly uncertain. There was little
improvement in reducing this uncertainty between the IPCC Third and Fourth Assessment Report.
Recent model improvements, however, may reduce this uncertainty in the future. One study produced
estimates of sea-level rise around the UK based on results from the IPCC AR4 (Lowe et al., 2009).
This study estimates absolute sea-level rise (which exclude changes in land level) around the UK for
the 21st century in the range of 12 cm (the lower bound of the Low emission scenario) to about 76 cm
(the upper bound of the High emission scenario). Larger rises could result from an additional ice sheet
term, but this is more uncertain. Another study estimated the plausible high-end scenario for 21st
century sea-level rise on the North Sea coast of the Netherlands in the range 40 to 105 cm (Katsman
et al., 2011). Making multi-decadal regional projections for relatively small isolated and semi-isolated
basins, such as the Mediterranean, is even more difficult than for the global ocean. One study made
projections for the Mediterranean Sea based on the output of 12 global climate models for 3 emission
scenarios (Marcos and Tsimplis, 2008). The results project an ocean temperature-driven sea-level rise
during the 21st century between 3 and 61 cm over the basin, which needs to be combined with a
salinity-driven sea-level change between - 22 and 31 cm.
1.1.3
Storm surges
Key messages

Several large storm surge events have caused loss of life and damage to property in Europe
during the past century. The most notable event occurred in 1953 when more than 2 000
people were killed, and there was massive damage to property around the coastline of the
southern North Sea.

There is strong evidence that extreme coastal water levels have increased at many locations
around the European coastline. However, this appears to be predominantly due to increases in
time mean local sea level at most locations rather than to changes in storm activity.

Large natural variability in extreme coastal sea levels makes detecting long-term changes in
trends difficult in the absence of good quality long observational records.

Multi-decadal projections of changes in storms and storm surges for the European region
currently have high uncertainty. The most recent studies indicate that increases in extreme
coastal water levels will likely be dominated by increases in local relative mean sea level,
with changes in the meteorologically-driven surge component being less important at most
locations.
Relevance
A storm surge is a temporary deviation in sea water level from that of the astronomical tide caused by
changes in air pressure and winds. Most concern is centred on positive surge events where the surge
adds to the tidal level and increases the risk of coastal flooding by extreme water levels. Changes in
the climatology of extreme water levels may result from changes in time mean local sea level (i.e. the
local sea level relative to land averaged over a year), changes in storm surge characteristics, or
changes in tides. Here the focus will be on changes in the storm surge characteristics, which are
closely linked to changes in the characteristics of atmospheric storms, including the frequency, track
and intensity of the storms. The height of surges is also strongly affected by regional and local-scale
geographical features, such as the shape of the coastline. Typically, the highest water levels are found
on the rising limb of the tide (Horsburgh and Wilson, 2007). The biggest surge events typically occur
during the winter months in Europe.
The most obvious impact of extreme sea levels is flooding (Horsburgh et al., 2010). The most well
known coastal flooding event in Europe in living memory occurred in 1953 due to a combination of a
8
[Climate change, impacts, and vulnerability in Europe]
severe storm surge and a high spring tide. The event caused in excess of 2 000 deaths in Belgium, the
Netherlands and the UK, and damaged or destroyed more than 40 000 buildings. Currently around
200 million people live in the coastal zone in Europe, and insurable losses due to coastal flooding are
likely to rise during the 21st century, at least for the North Sea region (Gaslikova et al., 2011). In
addition to the direct impact of flooding, increases in the frequency of storm surges can also
exacerbate other coastal problems, such as erosion, salt water intrusion, migration or river flooding.
Past trends
Producing a clear picture of either past changes or future projections of storm surges for the entire
European coast line is a challenging task because of the impact of local topographical features on the
surge events. Whilst there are numerous studies for the North Sea coastline, fewer are available for
the Mediterranean and Baltic Seas, although this situation is starting to improve. The uncertainty in
future projections of storm surges remains high and is ultimately linked to the uncertainty in future
mid-latitude storminess changes (see Section Error! Reference source not found.). This is an area
where current scientific understanding is advancing quickly, with some of the latest climate models
simulating significant differences in mid-latitude storm development, evolution and movement
(Scaife et al., 2011) compared to the generation of climate models used in current studies of future
storm surges.
The most comprehensive global studies of trends in extreme coastal sea level and storm surges
examined trends from hourly tide gauge records at least for the period since 1970, and for earlier
periods of the 20th century for some locations (Woodworth and Blackman, 2004; Menéndez and
Woodworth, 2010). The results show that changes in extreme water levels tend to be dominated by
the change in the time mean local sea level. In the north-west European region there is clear evidence
of widespread increase in sea level extremes since 1970, but much less evidence of such a trend over
the entire 20th century. When the contribution from time mean local sea level changes and variations
in tide are removed from the recent trends, the remaining signals due to changes in storminess are
much smaller or even no longer detectable.
Additional studies are available for some European coastal locations, but typically focus on more
limited spatial scales. A study that examined the trend in water levels at 18 sites around the English
Channel found that the rates of change in extreme water levels were similar to the rates observed for
mean sea level change (Haigh et al., 2010). However, the study also noted sizeable variations in storm
surge heights, with the largest surge intensity occurring in the late 1950s. This large natural variability
makes it difficult to detect changes in the rate of change in water level extremes. A similar
conclusion, that the change in annual maximum sea levels are increasing at a rate not significantly
different from the observed increase in mean sea level, was found in separate analyses for Newlyn in
the UK for the period 1915–2005 (Araújo and Pugh, 2008) and for 73 tide gauges along the Atlantic
and Mediterranean coastlines in southern Europe (Marcos et al., 2011). In contrast, significant
increases in storm surge height during the 20th century were found along the Estonian coast of the
Baltic Sea (Suursaar et al., 2009).
We conclude that whilst there have been detectable changes in extreme water levels around the
European coastline, most of these are dominated by changes in time mean local sea level. The
contribution from changes in storminess is currently small in most European locations and there is
little evidence that any trends can be separated from long-period natural variability.
Projections
Future projections in storm surges can be made using either dynamic or statistical modelling of storm
surge behaviour driven by the output of general circulation climate models (Lowe et al., 2010).
Several climate modelling studies have projected changes in storm surge height and frequency for the
21st century, mostly using the SRES A1B, A2 or B2 scenarios (see Subsection Error! Reference
source not found.). The results critically depend on the simulated changes in mid-latitude storms; this
[Climate change, impacts, and vulnerability in Europe]
9
topic remains a highly uncertain and rapidly evolving scientific field. The limited number of studies
that separate out any long-term climate change signal from multi-decadal climate variability suggests
that changes in atmospheric storminess are likely to be less important than increases in mean local sea
level
Early studies on future changes in surge magnitude in the North Sea region all identified certain areas
where increase in surge magnitude were projected, but they did not agree over its magnitude or even
which regions will be affected (Lowe et al., 2001; Hulme et al., 2002; Lowe and Gregory, 2005;
Woth et al., 2005; Beniston et al., 2007; Debernard and Røed, 2008). Furthermore, most of these
studies have not adequately considered that changes in various indices of storminess over the
European region exhibit decadal and multi-decadal oscillations (Sterl et al., 2009) (Jenkins et al.,
2007).
Two recent studies addressed some of the deficiencies in earlier studies by using ensemble
simulations of climate models to drive a surge model of the North Sea for the period 1950–2100. One
study found no significant change in the 1 in 10 000 year return values of storm surges along the
Dutch coastline during the 21st century (Sterl et al., 2009). The other study projected small changes in
storm surge heights for the 21st century around much of the UK coastline. Most of these changes
were positive but they were typically much less than the expected increase in time mean local sea
level over the same time period (Lowe et al., 2009). However, larger increases in storm surge for this
region during the 21st century cannot yet be ruled out.
A study on the Mediterranean region projected a reduction in both the number and frequency of storm
surge events during the 21st century (Marcos et al., 2011). A study on the Baltic Sea projected
increases in extreme sea levels over the 21st century that were larger than the time mean local sealevel rise for some future scenarios simulated by some of the climate models used (Meier, 2006). The
largest changes in storm surge height were in the Gulf of Finland, Gulf of Riga and the north-eastern
Bothnian Bay. A study on storm surges around the coast of Ireland projected an increase in surge
events on the west and east coasts but not along the southern coast (Wang et al., 2008). However, not
all of the changes were found to have a high statistical significance.
At some locations, such as Hamburg, local changes in bathymetry caused by erosion, sedimentation
and waterworks can have a much larger impact than climate change (von Storch and Woth, 2008).
Finally, recent work has shown that sea-level rise may also change extreme water levels by altering
the tidal range (Pickering et al., 2012).
1.1.4
Coastal erosion
Key messages

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, is expected to accelerate coastal erosion.
Relevance
Coastal erosion is the process of wearing away material from a coastal profile due to imbalance in the
supply and export of material from a certain section. It takes place in the form of scouring in the foot
of the cliffs or dunes or at the sub-tidal foreshore. Coastal erosion takes place mainly during strong
winds, high waves and high tides and storm surge conditions, and results in coastline retreat and loss
of land (Mangor, 2001).
10
[Climate change, impacts, and vulnerability in Europe]
More than 5 million people in Europe are living in areas at risk from coastal erosion and marine
flooding (defined as being below 5 m elevation, but not further than 1 km distance from the
coastline) (1). The increasing human use of the coastal zone has turned coastal erosion from a natural
phenomenon into a problem of growing importance for societies. Adverse impacts of coastal erosion
most frequently encountered in Europe can be grouped in three categories: 1) coastal flooding as a
result of complete dune erosion, 2) undermining of sea defences associated with foreshore erosion and
coastal squeeze, and 3) retreating cliffs, beaches and dunes causing loss of lands of economic and
ecological value (Conscience, 2010).
Coastal erosion in Europe causes significant economic loss, ecological damage and societal problems.
Loss of property, residential and commercial buildings, infrastructure, beach width, and valuable
coastal habitat causes millions of euros worth of economic damage each year and presents significant
management issues. At the same time protection is expensive. For example, in France some EUR
20 million is spent each year on mitigation measures and in the Netherlands the annual budget for
sand nourishment amounts to some EUR 41 million (Marchand, 2010).
Past trends
Many European coasts are endangered because they are being affected by coastal erosion. According
to the Eurosion Project (2) (Eurosion, 2004), about 20 000 km of coasts faced serious impacts in 2004.
Most of the impact zones (15 100 km) are actively retreating, some of them in spite of coastal
protection works (2 900 km). In addition, another 4 700 km have become artificially stabilised.
Figure Error! No text of specified style in document..3 shows the pattern of erosion and accretion in
Europe, including statistics for all European seas. The largest percentage of eroding coasts is found
along the Mediterranean and North Seas. The Baltic Sea is the only sea where the proportion of
accumulative coasts is larger than that of eroding coasts, mostly due to the isostatic land uplift in the
northern parts of the Baltic. In total, ca. 15 % of the European coastline was eroding, and about the
same length was accreting (almost exclusively in northern Europe); 40 % was stable, and data was
missing for the remaining 30 %. Other climate change drivers that may exacerbate erosion rates are
increased storminess, higher waves and changes in prevalent wind and wave directions.
1
2
Calculation by EEA, based on the 2001 population census.
See http://www.eurosion.org/ online.
[Climate change, impacts, and vulnerability in Europe]
11
Figure Error! No text of specified style in document..3
Coastline dynamics in Europe
Source: Deduce project (3) (http://www.deduce.eu/IFS/IFS26.pdf).
In some regions in Europe, coastal erosion can reach up to 2 m per year. The average annual rate of
erosion at the Holderness Coast in north-east England is around 2 m per year (Sistermans and
Nieuwenhuis, 2004). Erosion rates of more than 2 m per year during the period 1991–2001 were
observed at Forte Novo in the central Algarve in Portugal (Andrade et al., 2001).
Projections
Coastal erosion will be increased by climate change. Sea-level rise is one of the most important
drivers for accelerated erosion because it implies an increase in sediment demand, as retreating
coastline and higher sea levels will raise extreme water levels, allow waves to break nearer to the
coast and transmit more wave energy to the shoreline. Other climate change drivers that may
exacerbate erosion rates are increased storminess, higher waves and changes in prevalent wind and
waves directions (Marchand, 2010).
3
See http://www.deduce.eu/ online.
12
[Climate change, impacts, and vulnerability in Europe]