Science in Society Archive

Announcing an Important Scientific Publication

Sustainable Systems as Organisms?

The authors Dr. Mae-Wan Ho and Robert Ulanowicz present a new conceptual model for understanding sustainable systems as organisms that is opposed to the dominant model of unlimited growth. It is a breakthrough to understanding energy relationships in living systems that updates the ecological approach of Eugene and Howard Odum.

"It is the most important scientific paper I have written in my life so far," says Dr. Mae-Wan Ho, " and I owe it to my co-author Robert Ulanowicz."


Schrödinger (1944) marvelled at how the organism is able to use metabolic energy to maintain and even increase its organisation, which could not be understood in terms of classical statistical thermodynamics. Ho (1993, 1998a) outlined a novel "thermodynamics of organized complexity" based on a nested dynamical structure that enables the organism to maintain its organisation and simultaneously achieve non-equilibrium and equilibrium energy transfer at maximum efficiency. This thermodynamic model of the organism is reminiscent of the dynamical structure of steady state ecosystems identified by Ulanowicz (1983, 2003).

The healthy organism excels in maintaining its organisation and keeping away from thermodynamic equilibrium - death by another name - and in reproducing and providing for future generations. In those respects, it is the ideal sustainable system. We propose therefore to explore the common features between organisms and ecosystems, to see how far we can analyse sustainable systems in agriculture, ecology and economics as organisms, and to extract indicators of the system’s health or sustainability.

We find that looking at sustainable systems as organisms provides fresh insights on sustainability, and offers diagnostic criteria for sustainability that reflect the system’s health.

In the case of ecosystems, those diagnostic criteria of health translate into properties such as biodiversity and productivity, the richness of cycles, the efficiency of energy use and minimum dissipation. In the case of economic systems, they translate into space-time differentiation or organised heterogeneity, local autonomy and sufficiency at appropriate levels, reciprocity and equality of exchange, and most of all, balancing the exploitation of natural resources - real input into the system - against the ability of the ecosystem to regenerate itself.

Get the full paper here:

Article first published 25/05/05

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