Page 36 - Sustainability Communication Interdisciplinary Perspectives and Theoritical Foundations

2 Strong Sustainability as a Frame for Sustainability Communication 19

The concept of weak sustainability assumes far-reaching substitutability among
different types of capital. Accordingly, a fair bequest package consists of a constant
(cumulative) total level of capital. In practice, this means that nature can be con-
sumed, provided that other capital reserves (man-made capital, human capital) are
built up in its place. This would make it possible to envisage a future world where
there were for example no forests, provided that all of the functions forests currently
fulfil (production of wood, leisure functions, balancing effect on regional climate
systems, etc.) can be satisfactorily fulfilled by artificial means (synthetic substances,
nature films on TV, air conditioning etc.).
Weak sustainability envisages the different capital stocks of society in terms of
an overall portfolio, in which natural capital is only one among a number of different
stocks. The ideal portfolio manager would consider possibilities of substitution by
trying to maximise the net present value. From this point of view the preservation of
natural resources would be a meaningful and feasible goal only if it proved to be
more efficient when compared to other income types. For the sake of comparability,
natural resources have to be expressed in monetary terms. The deontological mean-
ing of intergenerational duties can only be described in terms of a constraint imposed
on maximization paths. The ethical idea is thus expressed as ‘non-declining utility
over time’.
Considering presumed limits of substitution between different capital stocks,
advocates of strong sustainability, like Herman Daly (1997), plead for a diversely
structured legacy. Regardless of the increase of other capital stocks, natural capital
should be at least maintained at a constant level for the sake of future generations.
Intuitively striking examples for the complementarity among capital stocks are the
relations between fish and fishing boats, forests and lumber mills, crude oil and
refineries etc. However, in principle this does not preclude the possibility of limited
substitution in particular cases. For Daly (1997) the assumption of complementarity
is a sufficient argument to justify the rule of strong sustainability, according to which
natural capital should not decline over time (the constant natural capital rule – CNCR).
However, further arguments can be introduced to justify the CNCR. In fact, it is not
only about whether or not and to what extent nature can be substituted in the pro-
duction process, but also about whether ‘we’ would want the ongoing substitution
of nature with regard to the capabilities approach or, in other words, whether ‘we’
can justify this substitution in the eyes of future generations.
The concept of strong sustainability relies on a ‘biospheric’ framing: According
to Daly (1997) the biosphere is characterised by living structures with a high degree
of internal complexity, i.e. negentropic structures. The whole industrial economy is
fundamentally reliant on the autopoietic regeneration of these very negentropic
structures that, together with raw materials, constitute a specific type of capital,
stocks and funds, which provides beneficial flows to human systems. Moreover,
nature is not only seen as a repository of resources, but also as an interlinked eco-
logical background in which economy and society are embedded.
The task of philosophical scrutiny is to develop a well-founded judgment that
provides a guide to a reasoned choice between these two concepts of sustainability.
The judging process takes place in due consideration of ethical principles and in a