Environmental Engineering Reference
In-Depth Information
The second type of instrument includes command and control regu-
lations. Situations may occur where economic activities need to be
restrained in areas that are especially rich in biodiversity to protect the
resource for present and future generations and yet it may not be pos-
sible to control market behaviour using incentives. Command and control
environmental regulations may be used in such circumstances. Regulatory
control involves the direct limitation or reduction of activities that degrade
an environmental resource in accordance with some legislated or agreed
standard (Barbier et al., 1994).
This is especially important where development initiatives that threaten
biological diversity involve uncertainty. In the case of risk, as opposed to
uncertainty, it is possible to completely list the range of possible outcomes,
and to assign an estimated probability to each outcome. Given this infor-
mation, and preferences over risk and return, rational decision-making
is possible. In circumstances of uncertainty, however, where the range of
possible outcomes is unknown, it is not possible to determine the expected
proi tability of a project. Although in the case of species extinctions a
probability can be attached to the loss of species, the total consequence of
this in terms of the loss of environmental services and ecosystem support
and duration of these ef ects cannot be known with certainty. Decision-
making in the presence of uncertainty relies not on rational comparison of
all options, but on adoption of some decision rule that has appealing prop-
erties (Common, 1995). It has been argued that a precautionary approach
to the conservation of biological resources should be adopted.
The policy of taking action before uncertainty about possible envi-
ronmental damage is resolved has been referred to as the 'precautionary
principle'. One justii cation for this is that the costs of damage to bio-
logical resources may exceed the costs of preventative action (Jackson
and Taylor, 1992). Also, irreversible damage may occur such as species
extinctions. The emphasis is thus on avoiding potentially damaging
situations in the face of uncertainty over future outcomes. It has been
proposed for decisions taken over the Convention on Biodiversity and
has been used in conjunction with the Montreal Protocol (Myers, 1992;
Haigh, 1993).
Ciriacy-Wantrup (1968) and Bishop (1978) have proposed 'the safe
minimum standards' approach, which involves setting quantitative, and
qualitative limits for, say, the preservation of species and their habitats. A
programme is developed to maintain such limits unless the costs of doing
so are 'unacceptably high'. Hanley et al.
(1991) indicate that sites of special
scientii c interest (SSSI) in the United Kingdom provide an example of
this approach in practice. These sites may be lost if the costs of conserva-
tion are prohibitive in terms of the government's conservation budget, but
