8.6.3 Limits to adaptation

Constraints to adaptation arise when one or more of the prerequisites for public-health prevention have not been met: an awareness that a problem exists; a sense that the problem matters; an understanding of what causes the problem; the capability to influence; and the political will to influence the problem (Last, 1998). Decision-makers will choose which adaptations to implement where, when and how, based on assessments of the balance between competing priorities (Scheraga et al., 2003). For example, different regions may make different assessments of the public-health and environmental-welfare implications of the ecological consequences of draining wetlands to reduce vector-breeding sites. Local laws and social customs may constrain adaptation options. For example, although the application of pesticides for vector control may be an effective adaptation measure, residents may object to spraying, even in communities with regulations to assure appropriate use. Increasing awareness of climate-change-related health impacts and knowledge diffusion of adaptation options are of fundamental importance to better decision-making.

Although specific limits will vary by health outcome and region, fundamental constraints exist in low-income countries where adaptation will partially depend on development pathways in the public-health, water, agriculture, transport, energy and housing sectors. Poverty is the most serious obstacle to effective adaptation. Despite economic growth, low-income countries are likely to remain poor and vulnerable over the medium term, with fewer options than high-income countries for adapting to climate change. Therefore, adaptation strategies should be designed in the context of development, environment, and health policies. Many of the options that can be used to reduce future vulnerability are of value in adapting to current climate and can be used to achieve other environmental and social objectives. However, because resources used for adaptation will be shared across other problems of concern to society, there is the potential for conflicts among stakeholders with differing priorities. Questions also will arise about equity (i.e., a decision that leads to differential health impacts among different demographic groups), efficiency (i.e., targeting those programmes that will yield the greatest improvements in public health), and political feasibility (McMichael et al., 2003a).