25 / 60
25
.
reducing vulnerability, possibly in hybrid solutions combining
‘grey’, engineered infrastructure with ‘green’ natural coastal
protection (Spalding et al. 2013), and including key local
stakeholders (Barbier, 2015). Coastal ecosystems can play a
role in making cities and human settlements safe even in the
case of coastal megacities. A recent study for New York City
(Aerts et al., 2014) shows that wetland restoration and beach
nourishment can be used in a hybrid approach to reducing
vulnerability to flooding.
In terms of providing protection from extreme events, coral
reefs, seagrasses, mangroves and dunes, can also, in certain
circumstances, provide protection against storm surges by
forming barriers along coastlines.
Number of people who may receive risk reduction benefits from reefs by country
10 000 - 50 000
330 000 - 670 000
50 000 - 120 000
670 000 - 2 150 000
120 000 - 330 000
more than 2 150 000
Coral reefs
Source:Ferrario&
etal
,
Theeffectivenessofcoral reefs
for coastal hazard risk reduction and adaptation
,2013
Pacific
Ocean
Pacific
Ocean
Atlantic
Ocean
Indian
Ocean
Coastal communities across the globe are increasingly at risk from storms and flooding as a side effect of climate change paired
with rapid human-led coastal development. Nature- based solutions like coral reefs offer a low-cost opportunity to reduce risk
and also can be paired with other ecosystems services such as tourism and fish production. The map above shows the number of
people by country that may derive a risk reduction benefit from reefs. The countries are grouped by the number of people living
below 10m elevation and within 50 km of a coral reef to demonstrate the capacity for coral reefs to protect coastal communities.
Such ecosystems can act in a similar manner to breakwaters
or shallow coasts. In this way, coastal ecosystems play a role
in reducing the impacts of climate change (SDG13
take urgent
action tocombat climatechangeand its impacts
), particularly the
increased frequency of storms and sea level rise. Importantly,
recent studies have also found that salt marshes can adjust
to sea-level rise and can reduce coastal erosion and increase
accretion, depending on a range of site-specific variables, as a
part of adaptation to climate change (Fagherazzi et al., 2013;
Shepard et al., 2011).