18.5. Adaptive Capacity and its Determinants
18.5.1. Vulnerability and Adaptive Capacity
Considerable attention has been devoted to the characteristics of systems (communities
or regions) that influence their propensity or ability to adapt (as part of
impact and vulnerability assessment) and/or their priority for adaptation measures
(as a basis for policy development). These characteristics have been called
determinants of adaptation. Generic concepts such as sensitivity, vulnerability,
susceptibility, coping range, critical levels, adaptive capacity, stability,
robustness, resilience, and flexibility have been used to differentiate systems
according to their likelihood, need, or ability for adaptation (Sprengers et
al., 1994; De Ruig, 1997; Klein and Tol, 1997; Smithers and Smit, 1997;
Adger and Kelly, 1999; Kelly and Adger, 1999). These characteristics influence
(promote, inhibit, stimulate, dampen, or exaggerate) the occurrence and nature
of adaptations and thereby circumscribe the vulnerability of systems and their
residual impacts. In the hazards literature, these characteristics are reflected
in socially constructed or endogenous risks (Blaikie et al., 1994; Hewitt,
1997). Together (in whole or part), they represent the adaptive capacity of
a system.
Table 18-5 lists terms that are commonly used to characterize the adaptive
propensity of systems to climate stimuli. There is considerable overlap in the
basic concepts captured in these terms. Particular terms have been employed
to distinguish natural from socioeconomic systems or to differentiate the condition
of a system before adaptation from its condition after adaptation (Klein and
Nicholls, 1998). These distinctions are important and can be captured without
narrowing the meaning of widely used terms. Thus, ecosystem vulnerability is
different from socioeconomic vulnerability.
| Table 18-5: Terms to describe characteristics of
systems that are pertinent to adaptationa (from Smit et al.,
1999). |
 |
| Sensitivity |
Degree to which a system is affected by or responsive
to climate stimuli (note that sensitivity includes responsiveness to both
problematic stimuli and beneficial stimuli)
|
| Susceptibility |
Degree to which a system is open, liable, or sensitive
to climate stimuli (similar to sensitivity, with some connotations toward
damage)
|
| Vulnerability |
Degree to which a system is susceptible to injury, damage,
or harm (one part—the problematic or detrimental part—of sensitivity)
|
| Impact Potential |
Degree to which a system is sensitive or susceptible to
climate stimuli (essentially synonymous with sensitivity)
|
| Stability |
Degree to which a system is not easily moved or modified
|
| Robustness |
Strength; degree to which a system is not given to influence
|
| Resilience |
Degree to which a system rebounds,
recoups, or recovers from a stimulus |
| Resistance |
Degree to which a system opposes
or prevents an effect of a stimulus |
| Flexibility |
Degree to which a system is pliable
or compliant (similar to adaptability, but more absolute than relative) |
| Coping Ability |
Degree to which a system can successfully
grapple with a stimulus (similar to adaptability, but includes more than
adaptive means of "grappling") |
| Responsiveness |
Degree to which a system reacts
to stimuli (broader than coping ability and adaptability because responses
need not be "successful") |
| Adaptive Capacity |
The potential or capability of a
system to adapt to (to alter to better suit) climatic stimuli or their effects
or impacts |
| Adaptability |
The ability, competency, or capacity
of a system to adapt to (to alter to better suit) climatic stimuli (essentially
synonymous with adaptive capacity) |
|
Adaptive capacity refers to the potential, capability, or ability of a system
to adapt to climate change stimuli or their effects or impacts. Adaptive capacity
greatly influences the vulnerability of communities and regions to climate change
effects and hazards (Bohle et al., 1994; Downing et al., 1999; Kelly and Adger,
1999; Mileti, 1999; Kates, 2000). Vulnerability has been described as the "capacity
to be wounded" (Kates et al., 1985). Human activities and groups are considered
sensitive to climate to the degree that they can be affected by it and vulnerable
to the degree that they can be harmed (Rayner and Malone, 1998). Because vulnerability
and its causes play essential roles in determining impacts, understanding the
dynamics of vulnerability is as important as understanding climate itself (Liverman,
1990; Handmer et al., 1999).
With regard to climate change, the vulnerability of a given system or society
is a function of its physical exposure to climate change effects and its ability
to adapt to these conditions. Chambers (1989) distinguishes between these two
aspects of differential vulnerability: physical exposure to the hazardous agent
and the ability to cope with its impacts. Thus, vulnerability recognizes the
role of socioeconomic systems in amplifying or moderating the impacts of climate
change and "emphasizes the degree to which the risks of climate catastrophe
can be cushioned or ameliorated by adaptive actions that or can be brought within
the reach of populations at risk" (Downing, 1991).
The significance of climate variation or change depends on the change itself
and the characteristics of the society exposed to it (Ausubel, 1991a; Rayner
and Malone, 1998; Munasinghe, 2000). These characteristics of society determine
its adaptive capacity and its adaptability. Adaptive capacity refers to the
ability to prepare for hazards and opportunities in advance (as in anticipatory
adaptation) and to respond or cope with the effects (as in reactive adaptation).
Studies of similar hazardous events recurring at different times in a given
region show vastly different consequences because of societal transformations
that occurred between the events. For example, rainfall and temperature fluctuations
in western Europe have far milder effects on human well-being today (society
generally is less vulnerable) than they did in the medieval and early modern
periods, essentially as a result of enhanced adaptive capacity that reflects
changes in practices, economics, and government programs (Abel, 1976; De Vries,
1977; Rayner and Malone, 1998). Similarly, particular climate events or hazards
can have "vastly different consequences for those on whom they infringe
because of differences in coping ability" (Rayner and Malone, 1998). An
extreme climatic event will result in higher losses of life in a developing
country than in a developed country because of differential adaptive capacity
(Burton, et al., 1993; Blaikie et al., 1994; Kundzewicz and Takeuchi, 1999).
Martens et al. (1999) describe potential adaptations to deal with increases
in disease incidence associated with climate change but note that in most poor
developing countries, socioeconomic, technical, and political barriers will
mean that the changed health risks will not be addressed.
" In developing countries overall social, environmental, and economic
vulnerability enhances the effects of droughts and other climatic events.
Overpopulation (relative to current productivity, income, and natural resources),
poverty, and land degradation translate into a poor capacity to face any kind
of crisis. Poor people have no insurance against loss of income. Weak economic
structures mean difficulties in maintaining jobs during an economic failure.
Degraded marginal lands become totally unproductive when precipitation decreases.
As a result, these regions have difficulty in facing climatic crises, although
such crises are recurrent. Any extreme climatic event can become a social
catastrophe when combined with the social-political characteristics of the
region. For example, the droughts and internecine wars in Ethiopia interact
to increase the adverse effects of both. Although developing regions are more
vulnerable to climate changes than are developed countries, the degree of
vulnerability varies in each specific region." (Magalhães, 1996)
Research on comparative adaptive capacity and vulnerability is evolving, and
its difficulties are well recognized (Bohle et al., 1994; Downing, 1996; Handmer
et al., 1999; Kelly and Adger, 1999). Estimates of adaptive capacity tend to
be based on premises such as the position that highly managed systems (such
as agriculture), given sufficient resources, are likely to be more adaptable
(and at a lower cost) than less managed ecosystems (Strzepek and Smith, 1995;
Burton, 1996; Toman and Bierbaum, 1996). It is also widely accepted that systems
with high levels of capacity to cope with historical and/or existing stresses
can be expected to have high adaptive capacity for stresses associated with
climatic change (Ausubel, 1991a). Such premises have formed the basis for broad
assessments of sensitivity and adaptability (USNAS, 1992). Of course, sensitivity
and adaptive capacity vary according to the climate change-related stress being
considered. Thus, adaptive capacity to gradual changes in mean temperature may
be high (or not much needed), but adaptive capacity to changes in the magnitude
or frequency of extreme climatic conditions may not be so high (Appendi and
Liverman, 1996).
