Geoscience Reference
In-Depth Information
typically formulated as risks, where the consequences of a given outcome are evalu-
ated alongside their probability of occurring. This may involve a prescriptive model
of the decision process, such as Cost Benefi t Analysis (Nas, 1996) or Multi-criteria
Decision Analysis (Herath and Prato, 2006), in which risks are evaluated, and pos-
sibly aggregated, systematically. Risk assessments typically ignore wider processes
of decision making, where problem defi nition and choice of decision framework are
crucial. Consequently, they are often criticised for their cursory treatment of people
as producers of uncertainty and risk. Particularly when risk assessments are under-
taken for policy and decision-making purposes (often the case in society-nature
issues), risk is now recognised as having multiple sources, multiple means of con-
ceptualisation, and multiple infl uences on decision making.
This chapter provides an overview of the origins, nature and implications of
uncertainty and risk for environmental research and decision making. First, it estab-
lishes a theoretical framework and consistent terminology for discussing uncertainty
and risk (second section). The third section focuses on causes of uncertainty and
risk in geographical enquiry, which are separated into psychological, social, and
situational factors. Approaches for assessing and communicating uncertainty
and risk are considered in the fourth section. Here, quantitative approaches to
assessing and controlling uncertainty are compared with more recent, deliberative
understandings (see Chilvers, this volume).
Alongside strategies for assessing uncertainty and risk, there are several pre-
scriptive strategies for managing them. These include the Precautionary Principle
(Harremoës et al., 2002), Life Cycle Analysis (Ciambrone, 1997), adaptive environ-
mental management (Holling, 1978), and ecological modernisation (Young, 2000).
This chapter focuses on the conceptual aspects of uncertainty and risk. (Further
details on these applied aspects can be found in Chapters 26 and 28 of this
volume.)
The Nature of Uncertainty and Risk
Discussions about uncertainty and risk are complicated by the varying ways in
which these concepts are defi ned and applied, both within and between disciplines.
Numerous taxonomies of imperfect knowledge have been proposed in recent years.
These include taxonomies for general types or levels of imperfect knowledge, such
as error, indeterminacy, uncertainty, and ignorance (Suter et al., 1987; Smithson,
1989), schemes that focus on particular sources of imperfect knowledge (Wätzold,
2000; Regan et al., 2002), and schemes that employ some combination of the two
(Walker et al., 2003). As the major sources of uncertainty vary between cases, it is
common for detailed studies to employ different terminologies.
Here,
uncertainty
is regarded as a lack of confi dence about our knowledge. Our
confi dence may vary from being certain that something is correct, incorrect (i.e., in
error) or irrelevant, to accepting that we have no useful knowledge for some practi-
cal application, such as decision making. Uncertainty occurs at varying levels in
between. It may be viewed as temporary, where some aspects of the environment
cannot be resolved in practice (e.g., direct observations of groundwater fl ow), or a
permanent condition, where some aspects cannot be resolved in principle (e.g., the
evolutionary state of humans 10
6
years into the future). The latter is known as
indeterminacy
. No distinction is made here between 'scientifi c uncertainty' and the
numerous 'other' uncertainties that affect environmental decision making, such as
