Many environmental problems faced today result from the accumulation of multiple small, often indirect effects rather than a few large obvious ones. Examples include loss of tranquility, heathland, and wetland, changes in landscapes, depletion of fish stocks, and global warming. These effects are very hard to manage on a project-by-project basis through EIA. The EIA comes too late, is too detailed, and is too focused on the short term. As such, despite the difficulties of doing so, SEA should make a special effort to consider cumulative, indirect, and long-term impacts (Therivel 2004).
For accumulation of effects from several projects, cumulative effects are used. According to Canter (1996), they are impacts on the environment that result from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency or person undertakes such other actions. Cumulative impacts can result from individually minor, but collectively significant, actions taking place over a period of time.
Cumulative effects may result from combined impacts from many, varied sources or repeated impacts from a single source. Cumulative impacts may be (Treweek 1999) additive (incremental), aggregated (synergistic), and associated (connected).
To evaluate cumulative impacts it is necessary to create a specific conceptual framework on which basis impacts will be identified and thereafter evaluated. Clark (1994) focused attention on the potential of cumulative effects assessment to serve as a predictive tool for gauging the sustainability of proposed development projects. According to this work, we propose the following steps for evaluating these effects:
1. Establish the geographic scope for the analysis and the time frame for the analysis
2. Describe the affected environment(this part includes evaluation of landscape character and ecological stability)
3. Identify other actions affecting the environment
4. Determine the environmental consequences of cumulative effect
5. Determine the magnitude and significance of cumulative effects
Our society and industry relies on large amounts of energy and the world is becoming increasingly dependent on fossil fuels (oil, gas, coal, etc.). The industrialized nations of Western Europe and North America, China, and India depend almost entirely on these fuels, and the developing nations are also increasing their use. It is understood that there is a direct link between the way we produce energy and damage caused by pollution. Finding cleaner and alternative ways of producing energy are now looked upon as being very important for the future of our planet.
On the basis of dozens of evaluated sustainable energy facilities (activities) assessed in the past 10 years as the specific aspects were determined: choice of locality—“brown fields” versus “green areas,” increased emphasis on cumulative impacts evaluation, clear suggestions are strengthening the proposed activities including their visualization and visibility evaluation.
To focus attention on the possibility of cumulative impacts is a way to call attention to disrupting the landscape where humans live. It is important to realize all the projects in harmony with landscape quality and respect its limits. To achieve this objective, it is necessary to accumulate knowledge about the environment from the beginning of the EIA process. A very appropriate way is to present its stability through the coefficients as we have shown in the case study in the Slovak Republic.
Acknowledgments We express our gratitude to the Slovak VEGA grant system for supporting our project 1/0544/11 as a basis for our research.