Closed Loop

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Problem

With the exception of sunlight and cosmic dust, the Earth is a closed system with a fixed amount of resources

Applies to all systems of reasonable size and complexity. Scale ranges from very large to medium, and long to medium timescales (see But section).

Drivers:

• Earth's resources believed to be inexhaustible
• belief that natural systems have an infinite capacity to absorb our waste
• belief that there is an 'away'
• negative connotation of 'waste'
• apparent simplicity of linear life cycle ('cradle to grave')
• shift towards synthetic materials that cannot be metabolized (either by natural or current technical systems)
• "Capitalism, as it is typically understood and practised, requires continual group and often some sort of 'free' input (in the form of water, air, waste disposal, unfair labor, etc.)" (Denise DeLuca)

Therefore

Nature recycle through numerous, interconnected physical and biological pathways. 'Waste' from one organism is a prized resource for others, effectively eliminating the concept of waste.

Examples include:

• hydrological cycle
• carbon cycle
• food webs
• Industrial Ecology
• Design for re-manufacturing (Gadgets That Self-Destruct)
• "Composting, particularly on-site composting. Land links and Farm transition programs that keep local lands in production and help local farmers produce food for local consumption. Community forestry (or other sustainable forestry) and Fire Wise programs that supply fuel for local biomass boilers." (Denise DeLuca)

Closed loop systems rely on Diversity - if all participants use the same inputs and generate the same outputs, it is unlikely that outputs can be linked to input. <Need more detail on exactly how someone might apply this pattern to a design challenge>

But

"Recycling as typically practised is usually not closed loop. It is usually "down cycling" where energy is added and value is diminished with each recycle! It actually encourages people to purchase single-serving containers." (Denise DeLuca)

"Also - 'closed loop' has to be defined within a context. All organic materials are part of a closed loop, but only if you look at the whole ecosystem in which they circulate." (Denise DeLuca)

Describe how application of the pattern may change the context.

Most of our existing technical processes are designed to be linear - resources are mined, manufactured into products, consumed and finally disposed in landfills where neither the embodied energy or materials can be reused.

See Also (Optional)

References to other patterns not mentioned elsewhere