Vulnerability, Impacts and Adaptation of Coastal Zones to Global Change - Vulnerability of Coastal Ecosystems and Adaptation - page 166

adaptation. Even considering the most disastrous scenarios for GMSL
rise by the end of the century, it is economically preferable to protect
the higher risk regions of the coast with dykes and other hard
structures [NIC 06, NIC 08] than to do nothing. The estimated
economic advantage of adaptation - defined as the difference between
the costs of the impacts without adaptation and the sum of the
adaptation costs plus the costs of the residual impacts - in Europe, in
2020, varies between 3.8 and 4.2 billion euros [RIC 10]. The same
models indicate that these values increase as we approach the end of
the century.
The costs associated with the impacts of GMSL rise and with
adaptation are very variable depending on the country and the regions.
Some developing countries, such as for example small economically
developing islands with low elevation, have a very limited capacity to
support the costs of implementing an adaptation strategy and the costs
of the residual impacts. The projected costs of adaptation and residual
damage, for a GMSL rise between 0.6 m and 1.3 m until the end of the
century, are between 1% and 9% of GDP in developing countries with
coastal zones vulnerable to flooding and submersion [ANT 10,
HIN 13]. Some of the most vulnerable countries are the low elevation
small island developing states in the tropical regions of the Pacific
Ocean (Salomon Islands, Marshall Islands, Kiribati, Tonga, Tuvalu
and Vanuatu), the Indian Ocean (Maldives and Seychelles) and the
Caribbean Sea (Antigua, Barbados and Nevis) [ANT 10]. China,
India, Bangladesh, Thailand, Myanmar, Vietnam, the Philippines,
Mozambique, Egypt and Nigeria are also developing countries with
coastal zones that are particularly vulnerable to GMSL rise. It is likely
that some of the most vulnerable countries, especially the small island
developing states, will reach the limit of their capacity to adapt before
the end of the century. In this situation, it will be necessary to have
recourse to retreat strategies, to the planned migration of populations
to other countries or to strategies involving the construction of
protection structures with outside aid. A World Bank study on the
adaptation costs in countries in developing regions [WOR 10]
concludes that the main component of the adaptation costs comes
from the construction and maintenance of dykes for coastal and river
protection in populated areas close to the coast, followed by the costs