The Use of Reference Values in Indicator-Based Methods for the Environmental Assessment of Agricultural Systems

Abstract

Many indicator-based methods for the environmental assessment of farming systems have been developed. It is not the absolute values of the indicators that reveal whether the impact of a system is acceptable, but rather the distance between these values and some reference values. We reviewed eight frameworks for the environmental assessment of agricultural systems that define reference values for their indicators. We analyzed the methods used to establish reference values and explored how to improve these methods to increase their usage and relevance. This analysis revealed a striking diversity of terminology, sources, and modes of expression of results. Normative reference values allow the assessment of a single system with a previously defined value; Relative reference values are based on indicator values for similar systems or a reference system. Normative reference values can be Science-based or Policy-based. A science-based normative reference value can be a Target value, which identifies desirable conditions, or an Environmental limit, which is the level beyond which conditions are unacceptable. The quantification of the uncertainty of reference values is a topic which is barely explored and warrants further research. Reference values present a means of introducing site specificity into methods for environmental assessment which seems, at present, largely under-exploited.

Elimination Method of Multi-Criteria Decision Analysis (MCDA): A Simple Methodological Approach for Assessing Agricultural Sustainability

“…"Normative reference values are defined based on science or policy (Experts and stakeholders may be involved), whereas relative reference values are based on indicator values for similar systems or a reference/ideal system. Normative reference values allow comparison of a system with previously defined reference values" [33] (p. 433). To produce a sustainability assessment which is robust, comparable, and transparent among stakeholders, it is important to clarify what type of reference point is being used in the sustainability assessment, as well as how the reference points were determined and why [33].…”

“…Normative reference values allow comparison of a system with previously defined reference values" [33] (p. 433). To produce a sustainability assessment which is robust, comparable, and transparent among stakeholders, it is important to clarify what type of reference point is being used in the sustainability assessment, as well as how the reference points were determined and why [33]. In the current study, relative reference values are used.…”

“…Reference values (Reference value is also referred to as "threshold", "fair earthshare", "critical flow" and "sustainability standard" [33] (p. 433) or thresholds are important considerations for elimination methods. Reference values can be determined using normative and relative considerations.…”

Advantages and limitations of exergy indicators to assess sustainability of bioenergy and biobased materials

“…It is remarkable that most methods for the assessment of agricultural sustainability (Acosta-Alba and Van der Werf, 2011;van der Werf et al, 2007;Van Passel and Meul, 2011), fall within the category of composite indicators. The sustainability analysis touches upon very diverse range of aspects that cannot be aggregated without having to turn to composite metrics in the end.…”

Sustainable development of agriculture: contribution of farm-level assessment tools

“…An overview of available tools was established using the search engine Scopus and the snowball method. The following list of reviews and scientific papers on sustainability assessments were identified through a literature study (Acosta-Alba and Van Der Werf, 2011;Binder et al, 2010;FAO, 2013a;Galan et al, 2007;Halberg et al, 2005;Marchand et al, 2012;Marta-Costa and Silva, 2013;Schader et al, 2014;Van Cauwenbergh et al, 2007;Van Der Werf et al, 2007;Van Passel and Meul, 2012). In addition, several recently developed tools that were presented at scientific conferences were added to the list and the developers were contacted to discuss the characteristics of the tools.…”