Wealth can be seen as the factories,
infrastructure, goods and services the population of a nation dispose of. According
to Tim Garrett,  a scientist who looks at
the economy from the perspective of physics, it is existing wealth that generates
economic activity and growth. This growth demands the

Wealth can be seen as the factories, infrastructure, goods and services the population of a nation dispose of. According to Tim Garrett,  a scientist who looks at the economy from the perspective of physics, it is existing wealth that generates economic activity and growth. This growth demands the use of energy as no activity can take place without its use. He also points out that the use of this energy unavoidably  leads to concentrations of CO2 in the atmosphere.  All this, Tim Garrett says,  follows from the second law of thermodynamics.  If wealth decreases then so does economic activity and growth. The CLD tries to illustrate how wealth, ironically, now generates the conditions and feedback loops  that  may cause it to decline. The consequences are  inevitably economic  stagnation (or secular recession?). 

You can read about the connection Tim Garrett makes between 'Wealth, Economic Growth, Energy and CO2  Emissions' simply by Googling 'Tim Garrett and Economy'.

  In CIV4 a City's Health stock is a flourishing yet complex condition which acts as a City attribute intended to limit growth. Positive and negative feedback impacts City Health flow and derives from many sources: city's site, buildings, wonders, civics, resources, population, etc.    What drives t

In CIV4 a City's Health stock is a flourishing yet complex condition which acts as a City attribute intended to limit growth. Positive and negative feedback impacts City Health flow and derives from many sources: city's site, buildings, wonders, civics, resources, population, etc. 

What drives this flow? When a cities unhealthiness is greater than its health limit, then for each point of population above the health limit consumes 3 food apiece rather than the standard 2 pieces. This further depletes city resources leading to starvation. In addition the city’s health also affects the rate at which it accumulates food. 


For example: too much growth causes overpopulation which leads to an unhealthy city. This unhealthy city leads to less food accumulation thereby resulting in starvation which further compounds the cities unhealthiness.
From Greenhalgh et al  article 2017 jimr  Beyond Adoption: A New Framework for Theorizing and Evaluating Nonadoption, Abandonment, and Challenges to the Scale-Up, Spread, and Sustainability of Health and Care Technologies 
From Greenhalgh et al article 2017 jimr Beyond Adoption: A New Framework for Theorizing and Evaluating Nonadoption, Abandonment, and Challenges to the Scale-Up, Spread, and Sustainability of Health and Care Technologies 
Simple tragedy ​of the commons behavior model.
Simple tragedy ​of the commons behavior model.
This model shows the operation of a simple economy. It demonstrates the effect of changes in the fractional rate of consumption (or the converse the fractional rate of saving.)  In summary, lower rates of consumption (based on production) result in higher rates of production and consumption in the l
This model shows the operation of a simple economy. It demonstrates the effect of changes in the fractional rate of consumption (or the converse the fractional rate of saving.)

In summary, lower rates of consumption (based on production) result in higher rates of production and consumption in the long-run.
Clone of Pesticide Use in Central America for Lab work        This model is an attempt to simulate what is commonly referred to as the “pesticide treadmill” in agriculture and how it played out in the cotton industry in Central America after the Second World War until around the 1990s.     The cotto
Clone of Pesticide Use in Central America for Lab work


This model is an attempt to simulate what is commonly referred to as the “pesticide treadmill” in agriculture and how it played out in the cotton industry in Central America after the Second World War until around the 1990s.

The cotton industry expanded dramatically in Central America after WW2, increasing from 20,000 hectares to 463,000 in the late 1970s. This expansion was accompanied by a huge increase in industrial pesticide application which would eventually become the downfall of the industry.

The primary pest for cotton production, bol weevil, became increasingly resistant to chemical pesticides as they were applied each year. The application of pesticides also caused new pests to appear, such as leafworms, cotton aphids and whitefly, which in turn further fuelled increased application of pesticides. 

The treadmill resulted in massive increases in pesticide applications: in the early years they were only applied a few times per season, but this application rose to up to 40 applications per season by the 1970s; accounting for over 50% of the costs of production in some regions. 

The skyrocketing costs associated with increasing pesticide use were one of the key factors that led to the dramatic decline of the cotton industry in Central America: decreasing from its peak in the 1970s to less than 100,000 hectares in the 1990s. “In its wake, economic ruin and environmental devastation were left” as once thriving towns became ghost towns, and once fertile soils were wasted, eroded and abandoned (Lappe, 1998). 

Sources: Douglas L. Murray (1994), Cultivating Crisis: The Human Cost of Pesticides in Latin America, pp35-41; Francis Moore Lappe et al (1998), World Hunger: 12 Myths, 2nd Edition, pp54-55.

This model also shows the operation of a simple economy. It differs from Model 1 primarily in the representation of all goods in the economy by units of measure of a higher level of abstraction. Thus, the same model can represent economies at different levels.  The simulation demonstrates how differ
This model also shows the operation of a simple economy. It differs from Model 1 primarily in the representation of all goods in the economy by units of measure of a higher level of abstraction. Thus, the same model can represent economies at different levels.

The simulation demonstrates how differing rates of consumption affect Savings.
​Farmers use intensive pesticides to harvest cotton, which is harmful to not only the health of the farmers using them, but also our environment as it pollutes rivers and groundwater that negatively interfere with the ecosystem. Even though these farmers know of the health and environmental risks, t
​Farmers use intensive pesticides to harvest cotton, which is harmful to not only the health of the farmers using them, but also our environment as it pollutes rivers and groundwater that negatively interfere with the ecosystem. Even though these farmers know of the health and environmental risks, they still use harmful pesticides to produce cotton, but why is this so. This stock and flow map should explain what impacts farmers to use pesticides to grow cotton despite the risks and explain the cause and effect relationship their use has on the cotton industry and the environment.
According to Clevo Wilson and Clem Tisdell article, "Why farmer continue to use pesticides despite environmental, health and sustainable costs,"

Pesticide use by farmers:
  • "used to reduce yield losses to pests"
  • "avoid economic losses to ensure economical survival"
  • "increase supply market and reduce market prices"
  • "ignorance of sustainable use"
  • "integral part of commercially grow high yielding varieties so without use, high yields may not be sustained"
  • "damage to agriculture land from the use occurs over long period of time so costs may not look serious short term, but reduces economic welfare in long term"
  • "environmental damage: pollutes rivers and groundwater, destroys beneficial predators and interferes with ecosystem overall"
  • "health risks underestimated"
  • "chemical companies selling it have incentive to push their use by advertising and promotion" (1,9).
A model of the ebb and flow of agricultural societies, like China's history. From Khalil Saeed and Oleg Pavlov's WPI 2006  paper  See also the Generic structure  Insight Map
A model of the ebb and flow of agricultural societies, like China's history. From Khalil Saeed and Oleg Pavlov's WPI 2006 paper See also the Generic structure Insight Map
 The term 'work' has been  used in this model in the sense of economic activity to include not only
work done by people but also by machines. The model shows 8 positive
feedback loops that reinforce work and the need to work. From the perspective of physics, civilisation can be described as a MECHAN

The term 'work' has been  used in this model in the sense of economic activity to include not only work done by people but also by machines. The model shows 8 positive feedback loops that reinforce work and the need to work. From the perspective of physics, civilisation can be described as a MECHANISM FOR USING ENERGY AND DOING WORK.  

Work, however, has some unavoidable consequences. The second law of thermodynamics tells us that any ‘work’ requires the use of energy and that DOING WORK entails the generation of WASTE HEAT. The laws of physics also tell us that CO2 emissions from burning fossil fuels will cause global warming. These unintended and unavoidable consequences are highlighted in the model by prominent arrows.

Can the structure of this system be changed to avoid a foreseeable collapse of civilisation?

Based on the Market and Price simulation model in System Zoo 3. Used in the System Thinking section of Regenerative Economics.
Based on the Market and Price simulation model in System Zoo 3. Used in the System Thinking section of Regenerative Economics.
WIP Summary of MIchael Hudson's  Book  Killing the Host: How Financial Parasites and Debt destroy the Global Economy 
WIP Summary of MIchael Hudson's Book Killing the Host: How Financial Parasites and Debt destroy the Global Economy 
This is part of series of model implemented from "Thinking in Systems" book by Donella Meadows
This is part of series of model implemented from "Thinking in Systems" book by Donella Meadows
 Modern industrial civilisation has created massive
interdependencies which define it and without which it could not function. We all
depend on industrial farming to produce the food we eat, we depend on gasoline
being available at the gas station,  on the
availability of electricity and even on the

Modern industrial civilisation has created massive interdependencies which define it and without which it could not function. We all depend on industrial farming to produce the food we eat, we depend on gasoline being available at the gas station,  on the availability of electricity and even on the bread supplied by the local baker. Naturally, we tend to support the institutions that supply the amenities and goods to which we have become accustomed: if we get our food from the local supermarket, it is likely that we would be opposed to it’s closure. This means that the economic system that relies on continuous growth enjoys implicit societal support and that nothing short of environmental disaster or a shortage of essential raw materials will impede it’s growing indefinitely. It is not hard to work out the consequences of this situation!

 The World3 model is a detailed simulation of human population growth from 1900 into the future. It includes many environmental and demographic factors. THIS MODEL BY GUY LAKEMAN, FROM METRICS OBTAINED USING A MORE COMPREHENSIVE VENSIM SOFTWARE MODEL, SHOWS CURRENT CONDITIONS CREATED BY THE LATEST W

The World3 model is a detailed simulation of human population growth from 1900 into the future. It includes many environmental and demographic factors.

THIS MODEL BY GUY LAKEMAN, FROM METRICS OBTAINED USING A MORE COMPREHENSIVE VENSIM SOFTWARE MODEL, SHOWS CURRENT CONDITIONS CREATED BY THE LATEST WEATHER EXTREMES AND LOSS OF ARABLE LAND BY THE  ALBEDO EFECT MELTING THE POLAR CAPS TOGETHER WITH NORTHERN JETSTREAM SHIFT NORTHWARDS, AND A NECESSITY TO ACT BEFORE THERE IS HUGE SUFFERING.
BY SETTING THE NEW ECOLOGICAL POLICIES TO 2015 WE CAN SEE THAT SOME POPULATIONS CAN BE SAVED BUT CITIES WILL SUFFER MOST. 
CURRENT MARKET SATURATION PLATEAU OF SOLID PRODUCTS AND BEHAVIORAL SINK FACTORS ARE ALSO ADDED

Use the sliders to experiment with the initial amount of non-renewable resources to see how these affect the simulation. Does increasing the amount of non-renewable resources (which could occur through the development of better exploration technologies) improve our future? Also, experiment with the start date of a low birth-rate, environmentally focused policy.









 Causal loop diagram capturing the interactions, trade-offs, and synergies between agriculture (SDG 2), water availability (SDG 6), economic growth (SDG 8), and life on land (SDG 15). Positive feedback linkages are shown as a positive sign (+), whereas negative feedback linkages are shown wi

Causal loop diagram capturing the interactions, trade-offs, and synergies between agriculture (SDG 2), water availability (SDG 6), economic growth (SDG 8), and life on land (SDG 15). Positive feedback linkages are shown as a positive sign (+), whereas negative feedback linkages are shown with a negative sign (−). The purple arrows indicate the enviro-biophysical linkages. The green arrows indicate the socio-economic linkages. The SDG icons are courtesy of the UN SDG communications material. 


Reference - Bandari, Reihaneh, et al. "Participatory Modeling for Analyzing Interactions Between High‐Priority Sustainable Development Goals to Promote Local Sustainability." Earth's Future 11.12 (2023): e2023EF003948.