Circular regenerative processes originally in the
biosphere, e.g., the carbon cycle which can be thought of as beginning and ending with atmospheric carbon dioxide and involving living organisms by processes of photosynthesis and ultimate degradation. Life cycles exist in the form of mass-energy conversions in the universe as well as in the form of the utilization (production, consumption and recycling) of resources in an economy, also called the business cycle. The circular process often leads to fluctuations of rhythms, e.g., economic recession and boom accompanied by fluctuations in unemployment, capital investment, trade, etc. (
Krippendorff )
