International assessments of the vulnerability.pdf - Climate ...

International assessments of the vulnerability of the coastal zone to climate change, including an Australian perspective
have generally not been considered in this report, but it is noteworthy that Hoegh-
Guildberg and Hoegh-Guildberg (2004) do undertake a study using the SRES
scenarios in relation to impacts on the Great Barrier Reef.
The IPCC CM has also been a stimulus for development of methods for vulnerability
assessment in the Asian region (McLean and Mimura, 1993) and throughout the
Pacific region, including the SPIM approach (Yamada et al. 1995; Kaly et al 1999;
Mimura and 2000; Hay et al 2003). However, in the Australian context the CM was
seen as being deficient, and less prescriptive approaches have been suggested for
testing on a jurisdictional basis (Kay et al., 1996; Harvey et al., 1999).
Although Australia is treated in global assessments, it is important to recognise that
these are often based on data-poor or deficient coastal descriptors that do not
adequately capture the variability of the Australian coast in time or space. In the most
recent modelling developments, the DIVA dataset has been considerably extended
from the earlier segmentation of world coasts primarily on a national basis. However,
despite the fact that DIVA undertakes calculations based on at least 188 coastal
segments around the Australian coast, it does not produce output at finer spatial
resolution than state level. Within Europe the jurisdictional boundaries are at much
smaller scale, and the relative vulnerabilities that are generated are of greater use in
terms of coastal management initiatives.
5.1 Metrics for analysis
One of the issues that needs to be considered is the metrics that are used to measure
vulnerability. A range of metrics assessing associated physical, biological and socioeconomic
impacts is reviewed in a forthcoming OECD report that considers sea-level
rise over the next 500 years (Nicholls et al., 2006). This report explores the issues,
develops methods to estimate the long-term dangers of climate change, and considers
the benefits of actions to mitigate the risks for coastal areas (Nicholls et al., 2006). It
summarises the issue of metrics based on discussions at a workshop and through a
questionnaire survey. Metrics are required, first to assess the exposure to climate
change, and secondly to consider the impact. This approach has utility also in studies
of erosion, independently of whether that is caused by climate change; for example
the EUROSION study in Europe adopted a series of indicators of pressure (equivalent
to exposure) and impact (Doody et al., 2004). Global sea-level rise scenarios (and
preferably ‘local’ sea-level rise scenarios) and elevation data are a prerequisite for
most metrics (Table 8). Some metrics measure exposure, others measure impacts,
costs of adaptations and residual risks.
The metrics outlined in Table 8 and used in the majority of global assessments of
vulnerability are not parameters that can be easily generalised for the considerable
length of the Australian coastline. There might be scope to develop approaches such
as the segmentation of the coast and calculation of vulnerability at segment level
within Australia if it is considered that the metrics generated could be meaningful in
the Australian context. However, it would be necessary to examine coasts at a
considerably finer scale than can presently be handled by models designed to establish
the relative vulnerability between different nations.
Australian Greenhouse Office, Department of the Environment and Heritage, 2006
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