Chapter 2 Integrated Risk and Uncertainty Assessment of Climate Change Response Policies
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2.6.5.4 Adaptation and vulnerability reduction
Compared to mitigation measures, investments in adaptation appear to be more sensitive to uncertainties in the local impacts associated with the damage costs of climate change. This is not surprising for two reasons. First, while both mitigation and adaptation may result in lower local damage costs associated with climate impacts, the benefits of adaptation flow directly and locally from the actions taken (Prato, 2008). Mitigation measures in one region or country, by contrast, deliver benefits that are global; however, they are contingent on the actions of people in other places and in the future, rendering their local benefits more uncertain. One cannot simply equate marginal local damage costs with marginal mitigation costs, and hence the importance of uncertainty with respect to the local damage costs is diminished (Webster et al., 2003).
Second, politically negotiated mitigation targets, such as the 2 °C threshold appear to have been determined by what is feasible and affordable in terms of the pace of technological diffusion, rather than by an optimization of mitigation costs and benefits (Hasselmann et al., 2003; Baker et al., 2008; Hasselmann and Barker, 2008). Hence, mitigation actions taken to achieve a temperature target would not be changed if the damage costs (local or global) were found to be somewhat higher or lower. This implies that mitigation measures will be insensitive to uncertainty of these costs associated with climate change. Adaptation decisions, in contrast, face fewer political and technical constraints, and hence can more closely track what is needed in order to minimize local expected costs and hence will be more sensitive to the uncertainties surrounding future damage costs from climate change (Patt et al., 2007, 2009).
There are two situations where decisions on adaptation policies and actions may be largely insensitive to uncertainties about the potential impacts of climate change on future damage. The first is where adaptation is constrained by the availability of finance, such as international development assistance. Studies by the World Bank, OECD, and other international organizations have estimated the financing needs for adaptation in developing countries to be far larger than funds currently available (Agrawala and Fankhauser, 2008; World Bank, 2010; Patt et al., 2010). In this case, adaptation actions are determined by decisions with respect to the allocation of available funds in competing regions rather than the local impacts of climate change on future damage (Klein et al., 2007; Hulme et al., 2011). Funding decisions and political constraints at the national level can also constrain adaptation so that choices no longer are sensitive to uncertainties with respect to local impacts (Dessai and Hulme, 2004, 2007).
The other situation is where adaptation is severely constrained by cultural norms and/or a lack of local knowledge and analytic skill as to what actions can be taken (Brooks et al., 2005; Füssel and Klein, 2006; O’Brien, 2009; Jones and Boyd, 2011). In this case, adaptive capacity could be improved through investments in education, development of local financial institutions and property rights systems, women’s rights, and other broad-based forms of poverty alleviation. There is a growing literature to suggest that such policies bring substantial benefits in the face of climate change that are relatively insensitive to the precise nature and extent of local climate impacts (Folke et al., 2002; World Bank, 2010; Polasky et al., 2011). These policies are designed to reduce these countries’ vulnerability to a wide range of potential risks rather than focusing on the impacts of climate change (Thornton et al., 2008; Eakin and Patt, 2011).
