Sustainability indicators: geology meets economy

Abstract Suggestions for defining and measuring sustainable development can broadly be placed in two categories: weak and strong sustainability. The concept of weak sustainability assumes that manufactured and natural capital are close substitutes. This means that the costs of environmental deterioration (e.g. groundwater damage) can be compensated by benefits from manufactured capital (e.g. income). Thus, environmental damage is valued in monetary units. The concept of strong sustainability denies the degree of substitution that weak sustainability assumes, at least for some critical elements of natural capital. This paper endorses the use of strong sustainability indicators, especially for critical loads and critical levels. These have to be pointed out by environmental scientists and/or geologists. Nevertheless, the costs and benefits of avoiding critical impacts have to be taken into consideration. Hence, a combination of strong and weak sustainability indicators is suggested.