EME 504
Foundations in Sustainability Systems

2.4 Strong Sustainability

Addressing degradation and depreciation of natural capital:

How we approach the idea of sustainable use of resources is directly related to how we decide how much of a resource we can use at any give time. This is measured using three different indicators:

  1. Net Yield (NY): extraction occurs as long as the cost of extraction is lower than the market price.
  2. Maximum Sustainable Yield (MSY): extraction occurs as long as the harvest rate is small or equal to the renewal rate.
  3. Optimum Sustainable Yield (OPS): extraction occurs as long as the use does not affect other parts of the ecosystem, and present and future uses of a resource.

To achieve Strong Sustainability, theoretically, we need to extract resources at the OPS. Clearly, one of the obstacles to address is how to ensure that extraction is not affecting other parts of an ecosystem. A second obstacle is how to predict future use of a particular resource. Can technology minimize the future need for a resource? Or is the opposite true?

It has been argued that strong sustainability is an unattainable ideal and that a more tractable type of sustainability is a more realistic scenario. That is, extracting at the MSY, which in some ways moves us away from environment-centered measurements of sustainability and places us in the territory of economic measurements, or weak sustainability.