Featured Stories
Free energy flow density as a measure of complexity
The astrophysicist Chaisson (2001) has proposed an interesting link between energy and complexity. Organisms can be viewed as dissipative structures: Ordered objects whose structure can be maintained thanks to a steady input of high-quality energy. The free energy flow density (ɸ) necessary to sustain such a non-equilibrium structure is a measure of complexity. It can be expressed in erg per second per gram or, more commonly, in mW per kg (1 erg = 107 joule). The free energy flows are [...]
Population overshoot, collapse and recovery: the role of climate change in medieval Europe.
How fragile the situation was in medieval times is illustrated in the historical reconstruction of population numbers in medieval France between the year 1000 CE and 1800 CE (Figure 4.8). The graph above shows France’s population and average Northern Hemisphere temperature relative to the period 1961–1990 (Mazoyer and Roudart 1997). Detailed analyses of agricultural practices and techniques reveal an increase in potential population density since the Carolingian era. A farmer in Mediterranean Europe needed in 900 CE about 16 hectares [...]
The Textbook
Written by prof. dr. B.J.M. de Vries, it provides an integrated, system-oriented introduction to the concepts, theories and issues surrounding the quest for a sustainable future for Planet Earth.Knowledge Base
We are building a knowledgebase of links, institutions and educational material, based on our understanding of sustainability science, as presented in the book.Models and Games
In this section we are collecting games, models and other interactive tools that can be used to teach sustainability science.Other Stories from our Blog
Energy: the Colosseum, slaves and containerships
The energy needed to deliver energy has always been a concern for societies. ‘All our societies require enormous flows of high-quality energy just to sustain, let alone raise, their complexity and order (to keep themselves […]
Networks: one way to understand system behaviour
Systems consist of elements and their interrelations or linkages. The theory which focuses on these linkages is called network theory. It is of great help to understand how systems behave and is being applied to […]
The Kaibab narrative: management on ill-understood systems
Numerous models of ecosystems have been made – but sometimes one wonders whether somewhere a reality can be found which more or less is described by such a model. The term empirical validation may be […]
Forests in Japanese history
Forests in Japan have been under pressure already for millennia (Totman 1989). More than 2000 years ago, rice culture caused the first dramatic modifications of woodlands and bronze and iron smelting started to put pressure […]
Demographic and territorial overshoot: India and Russia
Several historical accounts reinforce the impression that large populations of humans were living close to the environment’s carrying capacity and went through periods of severe food shortages and associated violence and hardship. One such a […]
Book and Website Reviews
Top-down or bottom-up, that is the question?
Every now and then I meet friends who have given up on changing the world: “It is too complex, too violent, too far away, and I feel powerless in the face of it. So I [...]
A simple introduction to system dynamics for sustainability – a report by Hördur Haraldson
We humans make mental ‘maps’ of processes around us in order to live and survive. Many of those maps are simplified, based on a limited set of acquired habits and experienced events. The maps also [...]
System dynamics for real-world complexity: a book by Erik Pruyt
In 2013, Dr. Erik Pruyt (Delft Technical University) has released a book on system dynamics, titled Small System Dynamics Models for Big Issues: Triple Jump towards Real-World Complexity. It is set up as an interactive [...]
Games for sustainability education, research and policy
One way to explore integration of the natural and the social sciences is the construction and use of simulation games and policy exercises (cf. Chapter 10 and 12). Since 2013 several websites have come online [...]