The purview of this book is the physical economy which are constrained by physical laws of a planet. Money economy is a social invention which is not bound to physical laws. Resources and sinks are needed to sustain the ecosystem. Renewable resources do regenerate, but these resources need time to regenerate. Should their extraction rate be faster than the rate they regenerate will reduce the stock. Nonrenewable resources are those which continuously reduce the total stock and will need to be substituted for should the stock run out. New source discoveries can increase the available stock, but the total stock of the resource will still diminish. The environment can recycle pollutants but if there are too many pollutants in the environment can overwhelm and destabilize ecosystem. The authors findings indicate that resources are being used too quickly and that the burden of waste on the environment is already showing negative impacts on health.
The authors created varies simulations based on system dynamics to show potential futures. The models show that resources needed for an expanding population and physical products will have to cope with many problems arising due to varied constraints. More and more capital inputs will be needed to deal with the problems. Eventually, capital will not be able to cope with increased problems thereby making further industrial growth impossible. The authors do not profess to accurately predict events, but they do claim to be able to rule out potentialities given current knowledge. They attempt to properly define expectation of resources use in the future. Their hope is that their predictions will be a catalyst to take action to make their predictions wrong. The authors use their expertise in dynamic systems to elaborate their values. They try to have an internally consistent paradigm which focuses on the changes in interconnections between material and immaterial elements.
The authors express three potential futures which are sigmoid growth, overshoot and oscillation, and overshoot and collapse. Sigmoid growth occurs when limits are respected and the responses to signals are quick and accurate which results in a smooth accommodation to the limits. Overshoot and oscillation occur when limits are surpassed and there is a delay in response. The corrections reduce stress on limits while over time overshooting them again until some equilibrium is set. Overshoot and collapse occur when the there is a delay to overstressed environmental limits which degrade the resource base leading to collapse.
Many systems tend to overshoot due to rapid change, limits to change, and limits in controlling the change. The problem is not with growth but exponential growth. With linear increase, the new stock does not depend on how much has already been accumulated which means that problems can be foreseen more easily and corrected. Exponential increase in new stock is proportional to what is already accumulated which means harder to control, predict interactions, and course corrections. Exponential growth cannot continue ad infinitum as there are only a finite amount of resources and space. With exponential growth, there is less time to take effective action.
Growth oriented policies are favored because they seem to fix a variety of national ailments. The authors favor a sustainable society which has the ability to rectify mistakes and increase quality of life rather than reckless abandon consumption. To rectify many problems will take a structural change in the system, not growth. Current practices need to change to sustain life within the ecosystem. Resources are needed to sustain life but the resources may not be sufficient. Agriculture is able to feed many more people but feed them inadequately. Recent increased agricultural was due to many policies which damaged the very environment needed to produce food.
The book is well written and provide some epistemological references to understanding the model. There are sections of the book which read like a technical manual on resources which at times can distract from the general situation. They provide complexity within the details. They do provide evidence that world change can save devastation with policies such as those which prevented further damage to the ozone layer. Even though this is a 30-year update to the original book, the authors do not give much references any major changes within the predictions and results.
What is needed is a structural change away from growth policies to a sustainable system. Technology can reduce some stress on the ecosystem but it will take social consumption changes to get to the root problem. Within the current economy, there are many techniques which can utilize resources more efficiently thereby providing more time to make other changes. What is needed is more accurate and constant information regarding the various sources and sinks. Transitioning to a sustainable system does not require no economic growth. Economic growth is permissible in the system, but that resources need to be used in a sustainable manner.
Pages to read: 444
1st Edition: 2010
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