The specific options for adaptation are wide-ranging. Often the existing capital assets could be used to the end of their design life and rebuilt to suit higher sea levels and increased risks of coastal erosion and flooding. In some cases, however, there may be a need for costly raising or relocation of railways, ports, bridges, dams, highways, electricity lines, and so forth; in other cases, the preferred option may be to build protective dikes, seawalls, and pumping systems. "Softer" options include setbacks of development zones, beach nourishment, dune protection, and phased retreat plans-options that increasingly are perceived as viable alternatives, especially in coastal zones facing high development pressures. These options are set out in guidelines issued by the Australian Institution of Engineers (1991).
The time frame for response to sea-level rise is sufficient, in principle, to allow for the development of suitable coastal policies and management practices to adjust. At present, however, in Australia coastal hazards are generally not well accommodated within current coastal management planning frameworks. This was highlighted for Australia in the Report of the Coastal Zone Enquiry (Resource Assessment Commission, 1993), which recommended a National Coastal Action Plan. The approaches to coastal hazard management of the six Australian states are summarized in Kay et al. (1996). In most cases, there is some way to go to factor in the relatively long-term issue of climate change.
In New Zealand, the overarching national policies attempt to guide and encourage adaptation at the local level. The RMA requires that alternative options be systematically evaluated during local resource consent procedures (s.32). The New Zealand Coastal Policy Statement directs that a "precautionary approach" should be adopted and states that reliance on coastal protection works should be avoided; an emphasis should be placed instead on the enhancement of natural protective features of coastal systems and on the location and design of new developments to avoid hazardous situations. This policy framework in New Zealand is a potentially powerful mechanism for promoting adaptation to reduce the impacts of climate change in the coastal zone. However, it is too soon to assess its effectiveness because very few regional and district policies and plans have completed the lengthy public submission and appeal processes required.
For the future, a key strategy for the Australasia region will be to consider adaptation options within the context of integrated coastal zone management (IPCC 1996, WG II, Section 9.6.4). Within this increasingly accepted approach, the necessary detailed hazard mapping, monitoring, and policy development can occur, and a range of sociocultural, structural, legal, financial, economic, and institutional measures can be developed to deal with any additional climate-related risks. Such advance planning may substantially reduce the later costs of adaptation.
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