Environmental Engineering Reference
In-Depth Information
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A clear enough future
Alternative futures
A range of futures
True ambiguity
oArange
of
oNo
basis to
°
A
few
discrete
A single forecast
ruSSi Ie outcomes
What can
forecast the
precise enough for
outcomes that define
ut no natural
be
known?
Mure
detennining strategy
theMure
scenarios
Figure 2.7
Levels of residual uncertainty
Source
: Courtney et al., 1997; 2001; Frommelt, 2008.
tip the balance in favour of another known alternative, and may even open up entirely new
options. A key concept within futures analysis is therefore that of uncertainty. Courtney (1997),
Courtney et al. (2001) and Frommelt (2008) describe different levels of 'residual uncertainty',
depending on the range of possible outcomes (
Figure 2.7
)
. These outcomes range from a
clarity of the future direction as moving in one direction, or the choices made between clearly
defined alternatives, or a range of possibilities placed within a solution space, or a more truly
unknown and random set of futures.
If these alternatives are augmented by a timeline, then a different sort of uncertainty occurs.
Van der Heijden (1996) (
Figure 2.8
) illustrates how the degree of predictability falls with
reduced knowledge of predetermined trends, and the uncertainty rises, the further we look in
time. In the very long term everything is uncertain and strategy is based, at best, on 'hope',
High
Uncertainty
Forecasting Scenario Hope
Predetermineds
Low
Distance into the future
Figure 2.8
Predictability and uncertainty
Source
: Van der Heijden, 1996.
