C6.3.1 Limitations of EIA


The limitations of EIA include:

  • EIA takes place once many strategic decisions have already been made. It can therefore often only address a limited range of alternatives and mitigation measures: those of a wider nature are generally poorly integrated into project planning.
  • Politics and models of decision making may be a disadvantage.
  • Uncertainty is an intrinsic factor.
  • There is an inadequate understanding of the behaviour of the environment.
  • This is a commitment dependent tool
  • EIA is susceptible to bias and personal interests (e.g. developer as well as pressure groups).
  • Quality of data (out of date or of insufficient detail).
  • Limited consultation.
  • Project EIAs are also generally limited to the project’s direct impacts. This approach ignores a wide range of impacts, including:
    • Cumulative impacts (the environmental impacts of multiple plans, projects and other actions).
    • Global impacts (impacts that go beyond the local, project level, e.g. climate change).
    • Indirect, secondary or induced impacts (impacts that occur several steps away from the original action e.g. new houses that generate more vehicle movements that increase air pollution that affect the flora in an area).
    • Synergistic impacts (where impact A + impact B have a total impact of more than A+B e.g. NOx emissions and ozone emissions together cause smog, which has impacts over and above those of just the NOx and ozone separately.
    • Finally, time and budget will be limited to some degree.