Thursday, March 01, 2007
Energy as the Catalyst in the Punctuated Equilibrium of Human Population Growth
The history of human cultural evolution is generally regarded as being closely linked to the development and evolution of agriculture. As man (initially in isolated local pockets) learned to plant seeds and grow his food rather than having to find it or chase it, human cultural evolution gradually moved toward the production of surpluses capable of supporting community building and urbanization.
It is generally argued that the "unnatural" growth in human population began with that simple act of planting a seed and the associated act of fixing a harness to an animal and having it pull a plow.
This whole argument, however, is one of observing results in isolation and to miss the underlying cause. The underlying catalyst to the growth of the human population is the exploitation of energy in its broadest context. The advance in human numbers, from the beginning of the history of man on earth, has been punctuated - in the context of Stephen J. Gould's theory of punctuated equilibrium in speciation and evolution - by the discovery, recognition, understanding and exploitation of new forms of energy. Even that first planting of favored seeds around the hunter-gatherer's camp site was a process of exploiting the energy contained within those seeds by which those seeds could reproduce the plant from which they came.
The nature of punctuated equilibrium in the growth of human population is completely different than punctuated equilibrium in the genesis and evolution of species. The spurts of human population growth are caused by our own activity. It is not dependent on genetic evolution but, rather, memetic evolution. We are responsible for our own pattern of punctuated equilibrium. Each spurt in human population growth, most notably that since the beginning of the industrial revolution, are closely linked to the discovery, recognition, understanding and exploitation of a new "energy source" in the broadest context.
What has pushed us into extreme exponential population growth since the beginning of the Industrial Revolution is a series of new and tightly overlapping energy exploitations closely following on a previous series of lower impact energy exploitations. All three fossil fuels had, before the industrial revolution, small scale local use. But other energy exploitations like the use of wind energy for windmills and sails, solar energy use in ovens, water energy in water wheels and the aqueduct systems like those built by the Romans, had all preceded the industrial revolution. But the overlapping cumulative exploitation of coal, oil, natural gas, electricity and nuclear had a truly revolutionary impact on human society and human population. Our numbers grew exponentially from about 850 million in 1700 to 6.5 billion at the beginning of this millennium just three centuries later. It is that cumulative contribution of so many very major new energy resources that has thrown the human population into the most extreme period of punctuated equilibrium and exponential growth in human history.
There is, however, another very worrying aspect of the punctuated equilibrium pattern brought on by the exploitation of new energy sources. Their application follows a standard Gaussian Curve or bell curve, application climbing relatively rapidly to a peak and falling rapidly with the discovery and exploitation of "the next" energy source. The worrying part is that growth in human population - usually local but sometimes, as now, global - follows the same Gaussian Curve. There is a short spurt of human population followed by a short term drop back to a level of stasis as the exploitation of that energy source goes into decline.
The current short (by historical standards) period of exponential growth in human numbers has been the result of a three century series of overlapping and cumulative exploitations of a half dozen unprecedented new energy sources. But the exploitation of all of these energy sources is moving rapidly toward a peak that will occur this century. As each of them peak there will be a corresponding negative impact on human population. This impact will gain negative momentum as the exploitation of each of these energy sources peaks and begins to decline. What is the level of population stasis to which we will decline as all of these energy sources falter? The population when we started up the steep slope of the Gaussian Curve was about 850 million. Most analysts of peak oil and other looming global crises believe the population will stabilize somewhere between one and two billion.
Based on historical trends it is more likely to be the lower figure of one billion.
However, there are approximately two billion people on the planet who arguably survive with no benefit from fossil fuels or any of the other energy sources that have driven our exponential rise in population. I would argue that they do, in fact, benefit indirectly from those energy sources through the importation of food, the mechanical exploitation of water sources, the availability of medicines produced by that exploitation of energy, and through the "manufactured" tools and other materials and goods they use and consume. I still, therefore, believe that the one billion number is more likely.
Historically, as well, the impact of the punctuated equilibrium on population has been localized to the relatively small geographic areas in which exploitation of the energy source is taking place. As a result these local population spurts had only minimal impact on global human population growth. With the growth of global trade in both goods and ideas that was such a key part of the industrial revolution, exploitation of these half dozen new energy sources , for the first time in human history, became global. The population of virtually every nation and region on earth grew - not at the same time or the same rate (Britain was experiencing a population increase of about 3% per year in the early stage of the industrial revolution while the overall world population was roughly static) - as the exploitation of these energy sources grew.
For the first time the Gaussian Curve of energy-mitigated population growth is global, an accumulation of all of the local growth patterns. Since growth in all of these areas, however, depends on the same globally traded energy resources, the slide down the back side of the curve will not be as spread out and gradual as it was on the up slope. This strongly suggests there will be a global population crash when these energy sources and resources go into irreversible decline and all nations experience the loss of benefit from these energy sources at the same time.
Population and Energy - Graham Zabel - http://dieoff.org/page199.htm
The Energy Crisis is Here by Stan Goff - http://www.williambowles.info/guests/energy_crisis.html
World Energy Production, Population Growth, And the Road to the Olduvai Gorge - Richard C. Duncan - http://www.hubbertpeak.com/duncan/road2olduvai.pdf
Tight Squeeze - By Mark Ridley - http://query.nytimes.com/gst/fullpage.html?res=9503EEDA1239F93AA25752C1A963958260
The Scientific Revolution - Introduction - E.L. Skip Knox, Boise State University -
Population Growth, Energy Use, and Pollution: Understanding the Driving Forces of Global Change - http://www.aag.org/hdgc/Population_Growth.html