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Article Excerpt
Introduction
It is increasingly accepted that accumulations of carbon dioxide and other greenhouse gases, in large part, are a result of human activity and are causing significant changes to the Earth's climate, notably increases in average temperatures (Houghton et al. 2001). However, the most recent report (2001) of the Intergovernmental Panel on Climate Change (IPCC) also outlines changes in the frequency, spatial distribution and magnitude of a number of climatic conditions, extremes and weather events likely to occur in coming decades (McCarthy et al. 2001). Many of these changes, if manifested, pose significant risks to human well-being. Drawing on scholarship in fields such as natural hazards and disaster management, the IPCC suggests that such factors as the extent of exposure, the sensitivity of the systems involved and the adaptive capacity of those exposed influence the vulnerability of human populations. It further suggests that the degree of vulnerability of a given population to risk may be reduced through enhancement of that population's adaptive capacity.
The IPCC notes that many human settlements can be expected to face an increased potential of flooding because of increased heavy precipitation events and sea-level rise (McCarthy et al. 2001). Higher maximum temperatures and more hot days are expected to occur over nearly all land areas, and increased summer continental drying and associated risk of summer drought is likely to occur over mid-latitude continental areas (McCarthy et al. 2001). Such changes in climatic conditions may be expected to pose concerns for areas of agricultural production (Bryant et al. 2000; Reilly et al. 2003).
Many human settlements in such environments have long been exposed to the risks of flooding or drought. Such manifestations of climate change can therefore be described as exacerbations of existing risks to which such communities are already exposed. In other words, the climatic conditions listed above represent potential increases in frequency, extent or magnitude of existing climatic or weather-related risks.
Because the likely manifestations of climate change include exacerbations of risks for which insurance may be obtainable, use of insurance can be considered as one the many possible adaptive options for climate change (Tol 1998; Vellinga and Mills 2001; Smit and Skinner 2002). In affluent societies, insurance is a mechanism that has been formed to assist people in coping with the adverse impacts of a wide range of events, both certain (e.g., death) and uncertain (e.g., automobile accidents). Many types of insurance have developed in response to risks associated with climatic conditions and weather events, such as crop failure and damage to property caused by storms, wind or floods, as well as events such as fire for which climatic conditions may be a contributing factor. While use of such types of insurance may potentially play a role in improving the capacity to cope with climate risks, it will be argued in the following discussion that, in some circumstances, insurance may have the conflicting effect of increasing the exposure of people and economic activities to such risks. Exposure to climate change will be shown to be not simply a measure of changes in biophysical or climatological conditions at a given place and time, but a product of human processes as well.
The aims of this paper are threefold. First, we set forth the concepts of risk and vulnerability from the research literature, which have become central to assessing the potential effects of climate change on human populations. Second, we reveal that although exposure and adaptive capacity are often treated separately, in climate change literature, they are not mutually independent variables and that they are invariably interconnected, and we thus offer a re-conceptualized model of climate-related risk to illustrate more closely these interconnections. This model is pertinent to those seeking to reduce human vulnerability to climate change risks, because actions taken to reduce exposure may cause changes in adaptive capacity--or vice versa. Third, we illustrate these ideas with examples of insurance for crop- and flood-related risks. In many western countries, governments subsidise such insurance, which serves to make the insurance more widely available; thus, more people who experience these types of losses are compensated. While this might seem to increase the ability of these populations to cope with a higher level of risk exposure, subsidization also tends to increase the number of people and economic activities exposed to the very risks that are being insured against.
Human Vulnerability to Climate Change
Many definitions have been offered to describe human vulnerability to natural conditions that may have adverse consequences (Cutter 1996; Clark et al. 1998; Liverman 2001; Weichselgartner 2001). Most describe vulnerability as the potential to experience harm or loss from some event or condition, and this potential is related to factors that affect the likelihood of the event or condition occurring and the ability to cope with or adjust to the effects of the event, if and when it occurs.
Human vulnerability to the broad range of risks associated with climate change can be represented with the model (1) (after Smit and Pilifosova 2003):
[V.sub.slit] = f([E.sub.slit], [AC.sub.sli]t) (1)
where V = vulnerability, E = exposure, AC = adaptive capacity, s = a given system or community, l= a given location, i = a given climatic stimulus and t = a given period of time. This model acknowledges that the vulnerability of a given community or system to climate change is specific to particular stresses or stimuli at particular locations and periods of time. There are two principal elements of vulnerability distinguished in the model. E refers to the probability or incidence of hazardous conditions relative to the presence of humans at a particular location at a particular time. AC refers to the ability of those exposed to...
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