Weak and strong sustainability

Weak sustainability

The concept of weak sustainability assumes that natural capital can be substituted with human-made capital, such as technology or infrastructure, so that the overall capital stock can be maintained for future generations. The approach follows the principle of “non-declining utility over time”. Focusing on economic growth and human welfare, it allows for trade-offs between environmental degradation and development as long as total capital remains constant. This relies on the belief that technological advancements can mitigate natural resource depletion or environmental harm. In contrast, critics argue that the concept underestimates the unique value of natural systems and therefore often link it to mainstream economic models (such as neoclassical approaches) prioritising short-term gains. Unlike, for instance, the above mentioned three pillars model which emphasises equitable integration of all three dimensions, weak sustainability allows for trade-offs that can undermine ecological integrity.

Strong sustainability

The concept of strong sustainability emphasises the unique value of natural capital, asserting that human-made capital cannot fully substitute for ecosystem services and natural resources. It prioritises the preservation of critical natural systems, like biodiversity and climate systems, for future generations, viewing them as irreplaceable. Consequently, economic activities have to operate within ecological limits, avoiding depletion or degradation of natural systems. The approach advocates for systemic changes to reduce resource extraction and pollution and thus does not necessarily follow an anthropocentric concept but rather assigns a moral value to nature itself.

Strong sustainability contrasts with weaker sustainability models by rejecting the idea that technology or wealth can fully compensate for environmental losses. However, also differently to the nested dependency model, which explicitly structures the three dimensions in hierarchical dependency, strong sustainability focuses on ecological limits without defining this hierarchy.