TOWARD A MASS BALANCE FOR HUMANITY

Garrett Hardin’s classic essay, ‘The Tragedy of the Commons’ (1968), eloquently expresses the finite nature of the non-renewable resource base on which human technological society depends: “In a finite world…the per capita share of the world's goods must steadily decrease”. While this statement is quite well-understood, estimating the total mass of those non-renewable resources remains a daunting challenge. In this presentation, a strategy to derive reasonable estimates of 1) the total quantity of non-renewable resources available to humanity, 2) the quantity of those resources utilized by human technological society to date, 3) the total quantity utilized annually, and 4) model projections for future use are outlined from the perspective of systems dynamics and mass transfer modeling. From the systems perspective, the non-renewable resource base is characterized as a relatively small number of discrete global reservoirs: soils, non-renewable energy resources (fossil and nuclear fuels), metals, glass resources (primarily geological deposits of quartzose sand), cement and industrial minerals (primarily limestone and other alumino-silicate minerals used in the built environment), and water. First approximations of the global quantity of matter in each reservoir will be presented with suggestions regarding likely future limitations. Quantifying the material flux of non-renewable resources through the human-environmental system is crucial to developing strategies for sustaining technological civilization. Thus, the mass balance of humanity is an important emerging concept in studies of sustainability and resilience of the global human-environmental system.