Identifying and Evaluating Impacts - Mining and the Environment: From Ore to Metal - page 397

TABLE 9.1
(Continued)

Health - Changes in health; medical services; medical standards; waste management
Personal security - Freedom from molestation; freedom from natural disasters/hazards; safety measures; security
Political - Authority; level and degree of involvement; priorities; structure of decision-making; responsibility and
responsiveness; resource allocation; local and minority interests; defence needs; contributing or limiting factors;
tolerances
Legal - Restructuring of administrative management; changes in taxes; public policy; statutory laws and acts; air and
water quality standards; safety standards; national building acts; noise abatement by-laws

Source:
Based on SCOPE 5 (1975)

are further discussed in Chapter Thirteen. Value judgements should be avoided at the
early stage of an environmental assessment, since the assessment of change signii cance
(including its nature) follows once changes and their interrelationships are identii ed. Note
that directly related to change is rate of change. A slow change may be acceptable, espe-
cially if it leads to a new stability, whereas rapid change or large l uctuations may place an
intolerable burden on humans and/or ecosystems.
Analyzing environmental change is simple in theory but not an easy task in practice.
The main challenges are differentiating between natural and project-induced change,
appreciating different value systems, acknowledging resource limitations, and understand-
ing the available methodologies to assess environmental changes.

A slow change may be
acceptable, especially if it leads to
a new stability.

Natural versus Project-Induced Change

'Would change occur in the absence of the project?' Even in the absence of humans, the natu-
ral environment undergoes continual change (see also related discussion in SCOPE 5, 1975
on which the following is partly based). This may be on a time-scale of hundreds of mil-
lions of years, as with continental drift and mountain-building, or over a period of a few
years or less, as with siltation of lakes or changes associated with natural geo-hazards such
as l oods, tsunamis, forest i res, or landslides. Some natural changes are irreversible (e.g.
destruction of ancient rain forest), while others are cyclic (e.g. seasonal climate variation or
El Nino events) or transient (e.g. droughts).
The natural environment appears static except where the results of human interven-
tion are evident. This is because most changes are imperceptible. However, changes do
occur and they do so at surprisingly rapid rates. Plant communities advance and retreat
with l uctuations in climate. Individual species of plants and animals invade new territo-
ries or are displaced from existing territories due to evolutionary adaptations or to changes
in climate and habitat that favour some species over others. Pollen preserved in lake bed
sediments show that numerous major changes in vegetation have occurred in Southwest
Australia within the last 1,000 years, in response to climatic changes. Over a time-scale of a
century, extensions or contractions of 40 km or more, have occurred repeatedly.
Superimposed on natural environmental changes are changes caused by human activi-
ties, such as developing a mine. Because the natural environment changes with time, it
is not always easy to distinguish incremental project-induced changes ( Case 9.1 ). But in
order to understand project-induced changes, it is necessary to know what environmental
conditions would have occurred had mine development not taken place. It is not an easy

Even in the absence of humans,
the natural environment
undergoes continual change.

It is not an easy task to
measure present environmental
conditions, the baseline, far less
to assess the signifi cance of past
trends and to extrapolate these
accurately into the future.