Coastal vulnerability, resilience and adaptation to ... - OceanDocs

tations to sea-level rise (for a more elaborate discussion see Klein and Nicholls, 1999). It was
used as the basis of assessments in at least 46 countries. The assessments aimed at identifying
populations and resources at risk and the costs and feasibility of possible responses to adverse
impacts. Quantitative results were produced in 22 country case studies (shown in Table
4) and eight subnational studies (Nicholls, 1995b).
It is important that the quantitative results in Table 4 are interpreted as being indicative
only. Studies using the Common Methodology were meant to serve as preparatory assessments,
identifying priority regions and priority sectors and providing an initial screening of
possible measures. Scientific uncertainties are compounded by uncertainties surrounding future
socio-economic developments and by the fact that the damage cost estimates are sensitive
to the use of discount rates. In addition, the impacts shown in Table 4 have been assessed
assuming a one-metre rise in sea level by 2100, whereas the latest scientific information,
as presented in Section 3.1, suggests a lower global mean sea-level rise. On the other
hand, one can argue that the results may well represent underestimates, because impacts on
non-market values have not been assessed and because the studies assume sea-level rise to
be a gradual process. As shown by West and Dowlatabadi (1999) and West et al. (2001), superimposing
current storm-surge variability on a gradual rise in sea level can lead to estimates
of damage costs that are an order of magnitude different from those based only on
gradual changes, where perfect foresight is assumed (cf. Yohe et al., 1996; Yohe and Neumann,
1997).
As noted by Klein and Nicholls (1999), many studies that used the Common Methodology
faced a lack of the accurate and complete data necessary for impact and adaptation assessment.
This has limited its applicability, which has led to the development of alternative assessment
methodologies (e.g., Kay and Hay, 1993; Gornitz et al., 1994). Nonetheless, no
other methodology has been applied as widely and evaluated as thoroughly as the Common
Methodology (e.g., Kay et al., 1996). Thus, it has contributed to understanding the consequences
of sea-level rise and encouraged long-term thinking about coastal zones. It also became
a model for assessing impacts and adaptation in non-coastal systems.
In 1994, the IPCC published its Technical Guidelines for Assessing Climate Change Impacts
and Adaptations (Carter et al., 1994), which provide generic guidance to countries that
wish to assess their vulnerability to climate change. For a range of socio-economic and physiographic
systems, the United Nations Environment Programme (UNEP) Handbook on Methods
for Climate Change Impact Assessments and Adaptation Strategies (Feenstra et al., 1998) then
offers a detailed elaboration of the IPCC Technical Guidelines, including for coastal zones
(Klein and Nicholls, 1998). The similarities and differences between the IPCC Common Methodology
and the IPCC Technical Guidelines are discussed in Klein and Nicholls (1999). Klein et
al. (1999) evaluate the guidance on adaptation assessment provided by the IPCC Technical
Guidelines.
Adaptation can play an important part in reducing the potential impacts of climate
change in coastal zones. In both the IPCC Common Methodology and the IPCC Technical
Guidelines, the guidance provided for adaptation assessment is limited. Rather than evaluating
a range of options using some formal decision-making framework (e.g., cost-benefit or
multi-criteria analysis), studies tended to consider only a protection versus a do-nothing scenario.
However, there are many different ways and options to respond to the impacts of sealevel
rise (see Section 4.3).
In fact, many of the early studies used a so-called “dumb farmer” scenario 2 : they assumed
that present-day behaviour and activities would continue unchanged in the future, irrespective
of how they might be affected by climate change. By ignoring any adaptation,
these studies did not distinguish between potential and residual impacts and thus their damage-cost
values represent serious overestimates. On the other hand, the studies, which are
not unique to agriculture, served to generate awareness of the potential magnitude of impacts
and the need for anticipatory adaptation.
2
The dumb farmer is a metaphor for any impacted economic agent that does not anticipate climate change or
act upon its manifestation. Instead, it continues to act as if nothing has changed. By not responding to changing
circumstances, the agent reduces its profitability or fails to take advantage of emerging opportunities. It thus
incurs larger damages than would have been the case had some adaptation taken place. The clairvoyant
farmer, on the other hand, has perfect knowledge and foresight and is able to minimise damages or maximise
benefits. As always, reality will be somewhere in between.
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