Can World3 be simplified? This is a model of the global human ecology. Closed systems are defined for carbon and land. An open system is defined for non-renewable non-fossil fuels in which the sink is external.  Energy is modeled as an open system with inflow from converters and outflow to various energy-driven human activities.
Model is in template form. Units are Tonnes (carbon or mineral (copper) ), Tonnes per Year, Hectares, Hectares per Year. 
Ready for input of real world values.  --CB 24Feb16
We have started putting real world data into the model.  Fill in stocks and flows by March 11. Be sure to cite the source of the data in the Notes section. --CB 5mar2016
Here is the land portion filled out to the best of our extent. All data has been acquired from the Food and Agricultural Organization of the United Nations (FAO, and Science ( Values for degraded and unusable land were calculated from total land. Agricultural land values were also calculated using calories produced globally over calories per hectare, and the values were consistent.  
J.N., T.R., L.B., Land group

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