Editing World3 (section)

=== Nonrenewable resources system ===
The nonrenewable resource system starts with the assumption that the total amount of resources available is finite (about 110 times the consumption at 1990s rates for the World3/91 model). These resources can be extracted and then used for various purposes in other systems in the model. An important assumption that was made is that as the [[nonrenewable resources]] are extracted, the remaining resources are increasingly difficult to extract, thus diverting more and more industrial output to resource extraction.

The model combines all possible nonrenewable resources into one aggregate [[Variable (computer science)|variable]], {{var|nonrenewable_resources}}.<ref name="dynamics_of_growth">{{cite book |last1=Meadows |first1=Dennis L. |last2=Behrens, III |first2=William W. |last3=Meadows |first3=Donella H. |last4=Naill |first4=Roger F. |last5=Randers |first5=Jørgan |last6=Zahn |first6=Erich |title=Dynamics of Growth in a Finite World |date=1974 |publisher=Wright-Allen Press, Inc. |location=Cambridge, Massachusetts |isbn=0-9600294-4-3}}</ref>{{rp|387}}  This combines both energy resources and non-energy resources.  Examples of nonrenewable energy resources would include oil and coal.  Examples of material nonrenewable resources would include [[Aluminium|aluminum]] and [[zinc]].  This assumption allows costless substitution between any nonrenewable resource.  The model ignores differences between discovered resources and undiscovered resources.<ref name="dynamics_of_growth" />{{rp|381}}

The model assumes that as greater percentages of total nonrenewable resources are used, the amount of effort used to extract the nonrenewable resources will increase.
The way this cost is done is as a variable {{var|fraction_of_capital_allocated_to_obtaining_resources}}, or abbreviated {{var|fcaor}}.<ref name="dynamics_of_growth" />{{rp|393-8}}  The way this variable is used is in the equation that calculates industrial output.  Basically, it works  as {{code|code=effective_output = industrial_capital*other_factors*(1-fcaor)}}.  This causes the amount of resources expended to depend on the amount of industrial capital, and not on the amount of resources consumed.<ref name="dynamics_of_growth" />{{rp|390-3}}

The consumption of nonrenewable resources is determined by a nonlinear function of the per capita industrial output.  The higher the [[Per capita income|per capita]] industrial output, the higher the nonrenewable [[resource consumption]].

[[Image:World3 nonrenewable resource sector.svg]]