The different calculations in nature apply concepts
from the natural sciences and try to describe
social processes of production and consumption in
natural science terms. However, the focal point of
these studies is the society and not the different
ecosystems of which humans are a part. For ecologists
this approach can seem limiting, and Carl Folke
argues that it has been too dominant in ecological
economics (personal communication). There is a
strong need to also apply approaches that take their
point of departure in ecosystems and deal with the
relations to human activities from the perspective of
the ecosystem. An example of such an approach
centres on the resilience concept, and it can be seen as
a way of dealing with the scale issue from an
ecological perspective (the following outline draws
heavily on Perrings, 1997; Levin et al., 1998; Folke,
1999). I elaborate on this perspective, which is
central, for example to the work of the Beijer Institute,
because it is important for the discussion of tensions
in the last part of this section.