What distinguishes strong sustainability from weak sustainability?

The distinction between strong sustainability and weak sustainability primarily revolves around the treatment and value of natural capital versus manufactured capital. Strong sustainability asserts that natural capital (the world's stocks of natural assets, including geology, soil, air, water, and all living things) has a unique and irreplaceable value. This perspective holds that certain natural resources cannot be substituted or converted into manufactured goods without losing their ecological functions and services. Therefore, strong sustainability advocates for the preservation and protection of natural ecosystems as critical to the well-being of future generations.

On the other hand, weak sustainability operates on the premise that manufactured capital can substitute for natural capital. In this framework, economic growth and development may be pursued with the understanding that human-made assets can effectively replace or replicate the services provided by the natural environment. This viewpoint tends to prioritize manufactured capital over natural capital, suggesting that as long as overall capital is maintained or increased, the degradation of natural resources may be acceptable.

Recognizing this fundamental difference in philosophy helps clarify why identifying weak sustainability as prioritizing manufactured capital is significant in discussions about sustainable practices and policies. This choice highlights the core debate about the extent to which humanity can continue to utilize natural resources without compromising the ecosystem services upon which we depend.