SYMP 20-1
The energy crisis: Physics, ecology, economics
Despite the low price of gas, humanity faces an energy crisis. We use the paradigm of an earth-space battery to show that the organic chemical energy essential for sustaining the functionality of the biosphere, human population, and economy is being rapidly exhausted.
1) Physics: Simple physics explains the unique impact of living things, including humans, on the energy balance of the earth relative to the thermodynamic equilibrium of outer space. 400 million years of photosynthesis (NPP) slowly charged a vast battery of organic chemical energy in the form of living biomass and fossil fuels. In the last few centuries this battery has been rapidly discharged by destruction of living biomass and combustion of fossil hydrocarbons. Living biomass is required to maintain the climate, biogeochemical processes, and biodiversity of the earth. Fossil hydrocarbons are required to sustain and grow the human population and economy.
2) Human ecology: Humans have drawn down the battery to grow the global population to the present 7.2 billion. Hunter-gather societies, where individuals met their metabolic needs by foraging for wild animals and plants, were in approximate equilibrium between NPP and human consumption. In contemporary society, energy expended for food far exceeds human metabolism. In the US, per capita energy expenditure for food production, distribution, and preparation is approximately 15% of total energy use and 15 times the human metabolic rate; approximately 90%, comes from fossil fuels. A small proportion of industrial farmers use machinery, water, fertilizers, and pesticides to feed the increasingly urban global population.
3) Economics: Humans have also drawn down the battery to grow the global economy. The industrial-technological-informational economies of the most developed countries consume about 100 times more energy per capita than the near-subsistence economies of the least developed countries. About 50% of recoverable stocks of petroleum have been burned in the last 200 years – 32 billion barrels of oil last year alone. Nevertheless most economists continue to discount the importance of “peak oil.”
Results/Conclusions
The earth-space battery has been rapidly discharged to grow a large unsustainable bubble of human population and economy. The only sustainable condition for humanity is a return to an approximate equilibrium between NPP and human metabolism, with a consequent reduction in population and standard of living. This will not be accomplished without suffering and sacrifice. But the longer the delay, the greater will be the inevitable catastrophic crash.