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Systems in Focus: Environment

One of the greatest environmental challenges we face is how to do more with less: Less raw materials, less pollution, less damage to the environment. This model shows the life-cycle assessment for the aggregate products manufactured and consumed in a firm, an industry, a region, a nation, or the world. It focuses on solid waste, though it would be easy to add air or water pollution generated and energy consumed at each stage.

The parameters in this model were anchored around one data point: The amount of solid waste discarded each year in the United States of America. Existing levels of resources were grossly estimated from a cursory glance at the literature. Population growth (not modeled), growth in the rate of extraction of nonrenewable resources, and sales demand are all based on the target GDP growth rate. Note that demand rises to meet production, as in Say's Law. In reality, these are simple approximations, but they suit the purpose of this model.

Systems in Focus: Environment model

Systems in Focus: Environment Model

The model includes four policy parameters with regards to controlling the amount of solid waste generated. The target GDP growth rate sets how much the government wants the economy to grow each year. The recycling rate controls the fraction of discarded goods that are recycled. The waste fraction controls the fraction of waste generated in the recycling processing. Finally, the average life controls the average lifetime of goods which, through planned obsolescence and technology improvements, continues to get smaller every year.

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