IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability

17.1 Concepts and methods

This chapter is an assessment of knowledge and practice on adaptation since the IPCC Third Assessment Report (TAR). In the TAR, adaptation and vulnerability were defined, types of adaptation were identified, and the role of adaptive capacity was recognised (Smit et al., 2001). Notable developments that occurred since the TAR include insights on: a) actual adaptations to observed climate changes and variability; b) planned adaptations to climate change in infrastructure design, coastal zone management, and other activities; c) the variable nature of vulnerability and adaptive capacity; and d) policy developments, under the United Nations Framework Convention on Climate Change (UNFCCC) and other international, national and local initiatives, that facilitate adaptation processes and action programmes (Adger et al., 2005; Tompkins et al., 2005; West and Gawith, 2005).

This chapter assesses the recent literature, focussing on real-world adaptation practices and processes, determinants and dynamics of adaptive capacity, and opportunities and constraints of adaptation. While adaptation is increasingly regarded as an inevitable part of the response to climate change, the evidence in this chapter suggests that climate change adaptation processes and actions face significant limitations, especially in vulnerable nations and communities. In most of the cases, adaptations are being implemented to address climate conditions as part of risk management, resource planning and initiatives linked to sustainable development.

This chapter retains the definitions and concepts outlined in the TAR and examines adaptation in the context of vulnerability and adaptive capacity. Vulnerability to climate change refers to the propensity of human and ecological systems to suffer harm and their ability to respond to stresses imposed as a result of climate change effects. The vulnerability of a society is influenced by its development path, physical exposures, the distribution of resources, prior stresses and social and government institutions (Kelly and Adger, 2000; Jones, 2001; Yohe and Tol, 2002; Turner et al., 2003; O’Brien et al., 2004; Smit and Wandel, 2006). All societies have inherent abilities to deal with certain variations in climate, yet adaptive capacities are unevenly distributed, both across countries and within societies. The poor and marginalised have historically been most at risk, and are most vulnerable to the impacts of climate change. Recent analyses in Africa, Asia and Latin America, for example, show that marginalised, primary resource-dependent livelihood groups are particularly vulnerable to climate change impacts if their natural resource base is severely stressed and degraded by overuse or if their governance systems are in or near a state of failure and hence not capable of responding effectively (Leary et al., 2006).

Adaptation to climate change takes place through adjustments to reduce vulnerability or enhance resilience in response to observed or expected changes in climate and associated extreme weather events. Adaptation occurs in physical, ecological and human systems. It involves changes in social and environmental processes, perceptions of climate risk, practices and functions to reduce potential damages or to realise new opportunities. Adaptations include anticipatory and reactive actions, private and public initiatives, and can relate to projected changes in temperature and current climate variations and extremes that may be altered with climate change. In practice, adaptations tend to be on-going processes, reflecting many factors or stresses, rather than discrete measures to address climate change specifically.

Biological adaptation is reactive (see Chapter 4), whereas individuals and societies adapt to both observed and expected climate through anticipatory and reactive actions. There are well-established observations of human adaptation to climate change over the course of human history (McIntosh et al., 2000; Mortimore and Adams, 2001). Despite evidence of success stories, many individuals and societies still remain vulnerable to present-day climatic risks, which may be exacerbated by future climate change. Some adaptation measures are undertaken by individuals, while other types of adaptation are planned and implemented by governments on behalf of societies, sometimes in anticipation of change but mostly in response to experienced climatic events, especially extremes (Adger, 2003; Kahn, 2003; Klein and Smith, 2003).

The scientific research on adaptation is synthesised in this chapter according to: current adaptation practices to climate variability and change; assessment of adaptation costs and benefits; adaptive capacity and its determinants, dynamics and spatial variations; and the opportunities and limits of adaptation as a response strategy for climate change.