6.6.5 The links between adaptation and mitigation in coastal and low-lying areas
Adaptation (e.g., coastal planning and management) and mitigation (reducing greenhouse gas emissions) are responses to climate change, which can be considered together (King, 2004) (see Chapter 18). The response of sea-level rise to mitigation of greenhouse gas emissions is slower than for other climate factors (Meehl et al., 2007) and mitigation alone will not stop growth in potential impacts (Nicholls and Lowe, 2006). However, mitigation decreases the rate of future rise and the ultimate rise, limiting and slowing the need for adaptation as shown by Hall et al. (2005). Hence Nicholls and Lowe (2006) and Tol (2007) argue that adaptation and mitigation need to be considered together when addressing the consequences of climate change for coastal areas. Collectively these interventions can provide a more robust response to human-induced climate change than consideration of each policy alone.
Adaptation will provide immediate and longer-term reductions in risk in the specific area that is adapting. On the other hand, mitigation reduces future risks in the longer term and at the global scale. Identifying the optimal mix is problematic as it requires consensus on many issues, including definitions, indicators and the significance of thresholds. Importantly, mitigation removes resources from adaptation, and benefits are not immediate, so investment in adaptation may appear preferable, especially in developing countries (Goklany, 2005). The opposite view of the need for urgent mitigation has recently been argued (Stern, 2007). Importantly, the limits to adaptation may mean that the costs of climate change are underestimated (Section 6.6.3), especially in the long term. These findings highlight the need to consider impacts beyond 2100, in order to assess the full implications of different mitigation and adaptation policy mixes (Box 6.6).