A Hierarchy of Natural Resources with Respect to Sustainable Development—A Basis for a Natural Resources Efficiency Indicator

Abstract

To resolve complex issues and establish guidelines for industry, politicians need data that can be transformed into indicators for policy decisions. Using a four-level hierarchy of natural resources as a base, a meaningful resource efficiency indicator can be developed as a tool for such policy decisions.

According to this concept, sustainable development implies substituting materials at a higher level of the hierarchy, either by material from a lower level, or by resources from the technosphere that replace resources from the same level in the geosphere. Energy resources occupy the highest level of the four-level hierarchy. Most problems concerning natural resources can be solved with enough affordable energy: water can be recycled after use; saline water can be desalinated; soil erosion through deforestation can be reduced by lessening the need for biofuel; cut-off grades in metal deposits can be lowered to increase available reserves; and lower-quality scrap metal can be recycled. The next hierarchy level is represented by raw materials derived from occurrences that developed over geological time and were formed by natural enrichment (e.g., all metal deposits and some non-metallic deposits such as barite or phosphate). This level also includes deposits of the technosphere that can be recycled. The third level comprises materials available in almost unlimited amounts on Earth, such as granite, sandstone, and clay, but also those raw materials that can be produced from air (e.g., nitrogen fertilizer), or from sea water (e.g., boron, potassium, or magnesium). Wood used for construction purposes is included in this third level because it is a renewable resource. The lowest level represents waste and residue materials from the technosphere that are potential raw materials for secondary use. Because energy resources occupy the top of this hierarchy, it makes sense to conserve energy by using more raw materials of lower ranking, rather than materials from the top levels. It then follows that in order to measure resource efficiency it is not appropriate to use a pure indicator, such as “total tonnage of natural resources produced or consumed in relation to the gross national product.” Instead, in establishing guidelines for political decisions designed to improve resource efficiency in a national economy, resource efficiency should mainly be measured in terms of an energy efficiency indicator.