Strong vs Weak Sustainability: two different approaches to Sustainable
development. The former defines development as non-consumption of natural
capital the latter defines development as non-consumption of overall total
capital (including human and social capital).
In the late 70s as the environmental issue started to unfold
and to be addressed by economists, different theories questioning the resource
paradigms. starting from the same question on how can we make the generations
yet to come have the same opportunities of satisfying their needs as we have
been able to do. Two theories emerged over the others, Strong and Weak
Sustainability. In a nutshell, according to Strong Sustainability the
consumption and regeneration of natural resources (natural capital) due to a
generation should balance each other out, whereas according to Weak
Sustainability, the balance should be in overall resources, including human and
social capital.
Indeed, according to Weak Sustainability variations of different
types of capital such as natural capital or manufactured capital can be
accepted as long as the aggregate total capital remains constant or increase.
On the other hand, Strong Sustainability advocates stress the fact that
consumption of natural capital is usually not reversible, while manufactured
capital can be restored with new goods. One more feature that is highlighted by
Strong Sustainability is that manufacturing capital can not be perfectly
exchanged with natural capital as natural capital is required for any kind of production
and provides security, basic materials for a good life, health, and good social
relations. Eventually, the whole Strong Sustainability point, comes down to
find the “critical natural capital” that is the threshold of defining how far can
we go in consuming resources without irremediably affecting the well-being of
the generations yet to come.
Basically, one example of a Weak Sustainability approach is
the concept of carbon tax. If you do not know what I am writing about, check in
our dictionary! Back to the carbon tax, as we do think that a certain amount of
pollution is not undermining human well-being as long as it can be compensated,
the degradation in natural capital due to CO2 emissions can be offset by an
increase in public capital
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From an operative point of view Weak Sustainability is much
more implementable in the short run than Strong Sustainability. In fact, one of
the main issues with Strong Sustainability is defining the tolerance threshold:
this is due to multiple factors. First, before even debating the norm there is the
need to a scientific assessment of the well-being that natural capital provides
to the public, but this is very difficult due to the fact that the “natural
service” provided is a “multidimensional” service, of whom not only humans
benefit. Second, the definition of such a threshold involves cultural values
that may differ from nation to nation, thus leading to different norms.