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to be given to development, the environment and social considerations, as well as short and long-term perspectives (Visser, 2004).

6.6.13 Tools for assessing adaptation needs and options

Since the TAR, many more tools have become available to support assessments of the need for adaptation and to identify appropriate interventions (Table 6.10).

6.6.1.4 Adaptation options

Figure 6.11 illustrates the evolution of thinking with respect to planned adaptation practices in the coastal zone. It also provides examples of current adaptation interventions. The capacity of coastal systems to regenerate after disasters, and to continue to produce resources and services for human livelihoods and well-being, is being tested with increasing frequency. This is highlighting the need to consider the resilience of coastal systems at broader scales and for their adaptive capacity to be actively managed and nurtured.

Those involved in managing coastal systems have many practical options for simultaneously reducing risks related to current climate extremes and variability as well as adapting to climate change (Yohe, 2000; Daniel, 2001; Queensland

Government, 2001; Townend and Pethick, 2002). This reflects the fact that many disaster and climate change response strategies are the same as those which contribute positively to present-day efforts to implement sustainable development, including enhancement of social equity, sound environmental management and wise resource use (Helmer and Hilhorst, 2006). This will help harmonise coastal planning and climate change adaptation and, in turn, strengthen the anticipatory response capacity of institutions (Few et al., 2004a). The timeframes for development are typically shorter than those for natural changes in the coastal region, though management is starting to address this issue. Examples include restoration and management of the Mississippi River and delta plain (Box 6.4) and management of coastal erosion in Europe (Eurosion, 2004; Defra, 2006; MESSINA, 2006). Identifying and selecting adaptation options can be guided by experience and best practice for reducing the adverse impacts of analogous, though causally unrelated, phenomena such as subsidence (natural and/or human-induced) and tsunami (Olsen et al., 2005). Based on this experience, it is highly advantageous to integrate and mainstream disaster management and adaptation to climate variability and change into wider coastal management, especially given relevant lessons from recent disasters (Box 6.5).

Table 6.10. Selected tools that support coastal adaptation assessments and interventions.

Description

Selected examples

Indices of vulnerability to sea-level rise

Thieler and Hammar-Klose, 2000; Kokot et al., 2004

Integrated models and frameworks for knowledge management and adaptation assessment

Warrick et al., 2005; Dinas-Coast Consortium, 2006; Schmidt-Thomé, 2006

Geographic information systems for decision support

Green and King, 2002; Bartlett and Smith, 2005

Scenarios - a tool to facilitate thinking and deciding about the future

DTI, 2002; Ledoux and Turner, 2002

Community vulnerability assessment tool

NOAA Coastal Services Center, 1999; Flak et al., 2002

Flood simulator for flood and coastal defences and other responses

Discovery Software, 2006; Box 6.2

Estimating the socio-economic and environmental effects of disasters

ECLAC, 2003

ICZM process sustainability - a score card

Milne et al., 2003

Monetary economic valuation of the environment

Ledoux et al., 2001 ; Ohno, 2001

Evaluating and mapping return periods of extreme events

Bernier et al., 2007

Methods and tools to evaluate vulnerability and adaptation

UNFCCC, 2005

Coastal adaptation (IPCC CZMS, 1990)

Adaptation objectives (Klein and Tol, 1997)

Adaptation responses (after Cooper et al., 2002; Defra, 2001)

Example

Protect

Accommodate

Retreat

-► Increased robustness

-► Land claim; empoldering

Estuary closure -► Dyke; beach nourishment

Increased flexibility ■

'Flood proof buildings Floating agricultural systems

Enhanced adaptability

Retreat the line-

Limited intervention No intervention -

-► Managed realignment Ad hoc seawall Monitoring only

Reversing maladaptive — trends

Improved awareness and preparedness

Sustainable adaptation-^ Wetland restoration

• Community-focussed adaptation

-► Flood hazard mapping; flood warnings

Figure 6.11. Evolution of planned coastal adaptation practices.

Klein et al. (2001) describe three trends: (i) growing recognition of the benefits of 'soft' protection and of 'retreat and accommodate' strategies; (ii) an increasing reliance on technologies to develop and manage information; and (iii) an enhanced awareness of the need for coastal adaptation to reflect local natural and socio-economic conditions. The decision as to which adaptation option is chosen is likely to be largely influenced by local socio-economic considerations (Knogge et al., 2004; Persson et al., 2006). It is also important to consider adaptation measures that reduce the direct threats to the survival of coastal ecosystems. These include marine protected areas and 'no take' reserves. Moser (2000) identified several factors that prompted local communities to act against coastal erosion. These included: (i) threats of or actual litigation; (ii) frustration among local officials regarding lack of clarity in local regulations, resulting in confusion as well as exposure to litigation; and (iii) concern over soaring numbers of applications for shoreline-hardening structures, since these are perceived to have negative, often external, environmental impacts. The particular adaptation strategy adopted depends on many factors, including the value of the land or infrastructure under threat, the available financial and economic resources, political and cultural values, the local application of coastal management policies, and the ability to understand and implement adaptation options (Yohe, 2000).

6.6.2 Costs and benefits of adaptation

The body of information on costs of adaptation has increased dramatically since the TAR, covering the range from specific interventions to global aggregations. Most analyses quantify the costs of responses to the more certain and specific effects of sea-level rise. Selected indicative and comparative costs of coastal adaptation measures are presented in Table 6.11. They reveal a wide range in adaptation costs. But in most populated areas such interventions have costs lower than damage costs, even when just considering property losses (Tol, 2002, 2007). Climate change affects the structural stability and performance of coastal defence structures and hence significantly raises the costs of building new structures (Burgess and Townend, 2004) or upgrading existing structures (Townend and Burgess, 2004). Financial cost is not the only criterion on which adaptation should be judged - local conditions and circumstances might result in a more expensive option being favoured, especially where multiple benefits result.

6.6.3 Limits and trade-offs in adaptation

Recent studies suggest that there are limits to the extent to which natural and human coastal systems can adapt even to the more immediate changes in climate variability and extreme events, including in more developed countries (Moser, 2005; Box 6.6). For example, without either adaptation or mitigation, the impacts of sea-level rise and other climate change such as more intense storms (Section 6.3.2) will be substantial, suggesting that some coastal low-lying areas, including atolls, may become unviable by 2100 (Barnett and Adger, 2003; Nicholls, 2004), with widespread impacts in many other areas. This may be reinforced by risk perception and disinvestment from these vulnerable areas. Adaptation could reduce impacts by a factor of 10 to 100 (Hall et al., 2006; Tol, 2007) and, apart from some small island nations, this appears to come at a minor cost compared to the damage avoided (Nicholls and Tol, 2006). However, the analysis is idealised, and while adaptation is likely to be widespread, it remains less clear if coastal societies can fully realise this potential for adaptation (see Box 6.6).

Adaptation for present climate risks is often inadequate and the ability to manage further increases in climate-related risks is frequently lacking. Moreover, increases in coastal development and population will magnify the risks of coastal flooding and other hazards (Section 6.2.2; Pielke Jr et al., 2005). Most measures to compensate and control the salinisation of coastal aquifers are expensive and laborious (Essink, 2001). Frequent floods impose enormous constraints on development. For example, Bangladesh has struggled to put sizeable

Table 6.11. Selected information on costs and benefits of adaptation.

Optimal (benefit-cost) coastal protection costs and remaining number of people displaced given aim rise in sea level (Tol, 2002) (see also Figure 6.11).

Region

Protection Costs (109 US$)

Number of People Displaced (106)

Africa

0 0

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