Environmental baselines are constantly changing, so the baseline description should also include predictions of likely future environmental conditions without the adoption of the strategic action. For instance, think back at what changes have happened in just the last five years in terms of mobile phone technology and use, genetically modified organisms, and obvious effects of climate change.
In some cases, the future baseline environment may be similar to today's: for instance, soil types generally change little over time, and it may be difficult to perceive climate change in the short term. In other cases, the baseline environment may change drastically even without the proposed strategic action. For instance, traffic levels may go up sharply in an area, increasing air pollution; or some large coal-fired power stations may come to the end of their life and be closed down, decreasing air pollution.
Predicting the future baseline conditions will enable the SEA to include a meaningful comparison with the 'future no-action' scenario. Predictions of future environmental conditions can be based on:
- an extrapolation of existing trends;
- development briefs, economic development plans, land use plans (draft as well as current);
- traffic and employment forecasts; and
- assumptions about new technologies (e.g. new automotive technology or forms of power generation).
A range of future conditions can be described using different scenarios, for instance best-case and worst-case scenarios. An example is shown below
Example of future baseline scenarios: from the Dutch Ten-Year Programme on Waste Management (Verheem, 1996)
"As a basis for the development of alternatives for the programming of final waste disposal capacity, two scenarios for the development of waste production to be expected in the future were developed: the "policy scenario" and the "headwind scenario". The policy scenario assumed that national objectives regarding waste prevention, reduction, separation, quality improvements and producer/consumer responsibility, as set out in legislation and national environmental management plans, would be fully achieved. It also assumed that future European waste management policy would be in line with policies established in north-western European countries. The headwind scenario assumed that these objectives would not be fully achieved, and that therefore more waste would have to be dealt with.
[The table below] indicates the different amounts of different types of waste to be expected (and thus that would need processing) in the future, following both scenarios. As a reference, the amounts of waste produced in the existing situation are given.
|Source: Verheem 1996||Type of waste||Present situation (year 1990)||Policy scenario (year 2000)||Headwind scenario (year 2000)|
|Normal domestic waste||4,680||2,203||3,532|
|Coarse domestic waste||540||438||470|
|Construction and demolition waste||3,500||1,996||4,006|
|Shredder waste (car wrecks)||120||136||153|
|Separate vegetable and garden waste||280||2,634||2,151|
Do you notice anything interesting about these scenarios?
Although total waste under the "headwind scenario" is greater than under "present situation", its composition is quite different, with less normal domestic waste and more vegetable/garden waste. Clinical waste also goes down over time. These reflect assumptions about trends that would happen regardless of the plan, e.g. improved sorting of waste at source, and increased composting.