Giani Gradinaru greenhouse gas emissions it is not possible to differentiate regions or periods in which radioactive pollution has a significant impact on human health or water is polluted with nitrates. On the other hand, environmental characteristics are not discrete. The variation of one of them corresponds with changes in others according to more or less known equivalences. Thus by knowing the level of greenhouse gas emissions it is possible to formulate an opinion about the acidification, since the pollutants come from the same source. Such patterns made environmental quality assessment a huge challenge for science. The results are individual indicators based on the supposition that their correlation with other environmental characteristics is strong enough to indicate the overall state of the environment; lists of indicators systematized according to different criteria (importance, environmental themes, environmental factors etc.) or conceptual models (PSR approach pressure-state-response, the 3E1I model – economy, equity, environment, institutions); and composite indexes that integrate a selection of indicators on the basis of rational conceptual underpinning. Some CEIs address environmental quality as a dimension of sustainable development. Each of these categories of solutions has a close score in terms of advantages and disadvantages. The higher operational potential, strengthening of construction methodologies and increasing availability of data enhanced the attractiveness of CEIs. In the last decades, there were built numerous CEIs, a quasi-complete list of them being provided recently by Singh et al. (2009). The construction of composite indexes follows a well-known methodology reviewed by OECD and JRC (2008). Nevertheless, the process is not smooth. Choosing indicators, normalization, and allocation of weights are the main phases influenced by subjective interpretations, while the choice of aggregation methods is clarified by Ebert and Welsch (2004), who establish the correspondence between data type and aggregation methods (Singh et al., 2009; OECD and JRC, 2008; Van de Kerk and Manuel, 2008; Böhringer and Jochem, 2007; Lee and Huang, 2007). CEIs are in the focus of scientific community not only as a goal, but also for assessment. There are envisaged the robustness and sensitivity of CEIs and the rational of the conceptual framework. JRC provides an up dated list of these studies. Such an assessment is the one performed by Böhringer and Jochem (2007) for eleven CEIs selected on the base of their „popularity” and information availability on construction methodology. The assessment take in account the methods used for normalization, weighing and aggregation. All eleven indicators fail in respecting the methodologies, some of these failures being beyond the restrains imposed by data availability. The operational potential of CEIs is often outweighed by the need of in depth knowledge about the conceptual framework underpinning their construction (Blanc et al., 2008), the complexity of causal relations that link human activities to environmental quality (Ayres, 2000), availability of data (Saisana and Srebotnjak, 2006), respecting methodological rigor (Böhringer and Jochem, 2007). Thus, a CEI comparable with gross domestic product (GDP) or human development index (IDU) is still not available.
3. International CEIS’ relevance for Romania Ecological footprint, living planet index, and environmental performance index will be assessed in order to reveal their relevance for Romanian environmental policymakers. This will be made by a decision exercise in which the analyzed CEI is considered the sole information source for governmental administration. Ecological footprint (EF) reveals the relation between consumption and availability of natural resources. Comparing EF with the global availability of productive surface provides an indicator of environmental sustainability which could be monitored for the identification of trends. In case that more productive space is needed than the one that is available, the consumption rate is not sustainable. The calculation of EF necessitates data on the low of resources for a number of activities such as transportation, energy and material use, product consumption, waste generation and water use. The impact of these activities is converted in a common currency – global hectares demand (ghd). By using this currency different impacts could be aggregated for calculating the EF of products, individuals, processes, organizations, regions, and countries. The method is using annual data. Calculations could be made at national levels, but there are also methodologies for companies, activity types or persons. The final value of EF is given by the sum for the following categories: built area, forests, pastures, cropped land, and carbon footprint.
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