Modelling catastrophic change The simplest mathematical equation that represents bifurcations and catastrophic change is a first order differential equation of the form: (eqn. 1) Solving for the attractors (dX/dt = 0), it is seen that one root is X = 0 and it represents a globally unstable attractor and the other two roots are [...]
Already for decades, ecologists are aware that proper modelling and management of fisheries has to incorporate the behaviour of fishermen. An early example was a model of two different fishing strategies (Allen and McGlade 1987). A more recent analysis investigates different harvesting strategies in an anegnt-based simulation model (ABM) (Brede and de Vries 2009). Let [...]
There are some empirical, illustrative case-studies in which catastrophic did happen. The first classical example is the interactive dynamics between the spruce budworm, its predators and the boreal forest in North America (Holling 1986; Meadows 2008). When the budworm became a ‘pest’ and northern forests were sprayed with the insecticide known as DDT to control [...]
Definitions Systems consist of elements and their interrelations or linkages. The relations between elements have received ever more attention in science, reinforced by the advent of ICT and in its applications in social media and AI. In particular information flows connecting elements are of great societal relevance. As Harari (2024) warns: "... humankind gains enormous [...]
History of Kaibab plateau 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 too strong, the aim is model-based story-telling. There are some interesting real-world stories to tell about [...]
Change is an elementary phenomenon in life. It is most visible in movement of matter. It is useful to look at a simple, well observable and controllable system: a mass m at the end of a spring. It is the classical model of linear elasticity, associated with the 17th-century British scholar Hooke. Change is in [...]
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 tend to assume single and linear relationships between causes and effects. Assuming that more cars (A) cause more traffic accidents [...]
There are quite some book on system dynamics which make a connection with sustainable development problems and solutions. Based on personal contacts, I choose two for a brief intrduction. The first one is the book Managing Complexity in Social Systems - Leverage Points for Policy and Strategy (2nd ed. 2023) by Christoph Mandl. The seond [...]
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 about games for sustainability. Some of these are (very) simple games about public goods, used in what has become known [...]