ABSTRACT
Prognostications on human ecological sustainability are difficult to make because the governing variables are related in a complex, nonlinear, nonstationary manner. Also, changes in variables often occur slowly, dulling our perception of them. For example, we can take the record of atmospheric CO2 concentration ([CO2]) over time and use various numerical extrapolation programs to predict what the [CO2] will be in 2050, or even in 2100. There is a certain mathematical purity in doing this, which inspires confidence in the results, but this confidence is necessarily based on the past (and present) [CO2] records, plus estimates of future emissions and the conditions that affect them. The actual future value of [CO2] in 2050 will be influenced by, among other things, the world population growth, our future rate of combustion of all carbon-containing fuels, the types of fuels themselves, and the global phytomass (CO2 uptake for photosynthesis and release by decay). Fuel combustion, in turn, depends on the population, the economies of countries, and their rates of development, whether the world’s vast oil, natural gas (NG), and coal reserves are successfully exploited, whether societies will learn to live with less energy in general, and whether renewable energy sources (solar, wind, hydro, tidal, wave) continue to be developed. Further fossil fuel (FF) prospecting, energy conservation, and the development of non-FF sources are all connected to the economies of countries. Economies around the world at present are in flux (look at the United States; the United Kingdom; the European Union including Greece, Italy, Spain, etc.). Inflation of FF energy prices means less FFs will be burned, particularly in countries having recessions; their standards of living will fall.
