Vulnerability, Impacts and Adaptation of Coastal Zones to Global Change - Vulnerability of Coastal Ecosystems and Adaptation - page 167

of beach nourishment and, lastly, the costs of protecting port
infrastructures.
Developed countries have a greater capacity to adapt to the impacts
of climate change on their coastal zones, but the value of coastal
assets subject to the risk of flooding and submersion is considerably
higher than in developing countries. It is very likely that from now
until the end of the century, the increase in adaptation costs will make
the protection of all coastal assets impossible in many developed
countries. It therefore becomes necessary to make choices and
prioritize the assets for protection.
The vast majority of adaptation cost estimates have been made
from a strategic point of view of protection, and mostly with hard
engineering structures. It is more difficult to make cost estimates for
accommodation strategies, due to the greater diversity of adaptation
options and the greater variability of costs in different regions of the
world. In the future, it is particularly important to develop further, the
cost estimates of facilitating the adjustment of the ecosystems
themselves since it is likely that the conservation of natural coastal
systems constitutes an adaptation approach with more chance of being
successful in the medium and long-term. It is also necessary to bear in
mind that, for highly urbanized low elevation coastal regions,
vulnerable to the risk of flooding and submersion, the acceleration in
the annual rate of increase of GMSL will lead to situations where hard
coastal protection infrastructures can be seriously damaged or
ruptured, which could be catastrophic.
There are still few studies concerning the adaptation of coastal
zones in multisecular time horizons where the rise in GMSL could
reach several meters. In Tol et al. [TOL 06], we can find an analysis
and discussion on adaptation in three European regions - the deltas of
the Rhône and Rhine and the City of London - to an extreme scenario
where, starting in 2030, the GMSL rises five meters during a period of
about 100 years, due to the collapse of the West Antarctic Ice Sheet.
In these examples, the likely adaptation strategies for responding to
the risk of flooding and submersion vary between the retreat from
highly vulnerable urban zones, accommodation and protection with
very large and high dykes. The situation will be even more difficult in