Various articles have shown up in the news recently regarding a prediction that the Earth’s human population would reach 7 billion by the end of 2011.  We are all familiar with the “hockey stick” graph of human population growth.  This graph has been commonly used to show the exponential rise in human population and therefore illustrate how our impact on the Earth is greatly increasing every day.  It was used, with great success, in Al Gore’s 2006 documentary “An Inconvenient Truth” to exemplify how easy it is for the human population to do great harm to our environment as our population continues to rocket to unprecedented levels.  The more humans the Earth harbors, the more power we have to cause harm.  However, the catastrophic damage predicted by theories about global warming are based on humans continuing this trend of careless resource consumption at an astronomical rate.  The negative effects of human caused climate change, which are predicted to occur over the next couple centuries, may not be our most pressing worry.  As the Earth’s food production resources are pushed to their extremes, we face a dilemma, can the Earth support very many more people?

The maximum population of a certain species that an environment can accommodate sustainably is called the “carrying capacity.” When populations increase beyond their carrying capacities, detrimental consequences can occur (Wright 2004).  In Ronald Wright’s book, “A Short History of Progress,” he uses the example of the former population on Easter Island to show the effects of this type of strain on a system.  The population of Easter Island increased far beyond the population that the island’s resources could have sustained (Wright 2004).  This resulted in mass deaths and eventually the total loss of the Easter Island population (Wright 2004).  Various studies based on modern technologies and accounting for future increases in production often put the earths carrying capacity at around 10 billion humans.  When we go over this number we cannot simply leave the island, not can we invent new technologies that allow us to create more resources than the Earth can supply.  Once a population begins to consume more than its environment can provide, it is only a matter of time before a system collapse occurs (Wright 2004).  Now for the really bad news: at the currently estimated rate of growth, the Earth’s population is expected to reach 9.3 billion humans by the year 2050.

New technology is the only real way we as humans can exploit the maximum possible carrying capacity of the Earth.  Technologies that allow us to better exploit natural food resources will help us accommodate more people but only to an extent.  When the process of agriculture began during the Neolithic period, the human population began to increase.  This same trend occurred again during other revolutions until finally the “Green Revolution,” which occurred in the mid 20th century, caused a massive increase in agricultural technological innovations, which greatly increased our food production capabilities.  With these new technologies, we finally saw the near vertical rise in human population seen in the last 50-100 years depicted in the hockey stick graph.  This is a classic example of an unchecked system going into an “exponential runaway” as described by Gregory Bateson (1972).  Bateson also explains “that a population of health individuals cannot be directly limited by the available food supply” (1972).  Eventually this will cause a “breakdown of the system” in which our society will not be able to sustain itself due to a lack of resources (mainly food), leading to mass starvation and system collapse.  As predicted by Wright, humans will inevitably meet their demise at the cost of their own strive for progress (2004).

As humans, we can live without much of the modern day comforts we consider part of life, but we cannot live without food.  Food is one of our most important commodities and we must be careful not to expect the Earth to supply more food than it possibly can.  Unfortunately by increasing our food production through technology, our food systems are now tied into other fragile and non-renewable systems.  For example, modern agricultural practices are reliant on oil.  When the Earths fossil fuel reservoirs are finally emptied, we will no longer be able to produce nearly as much food and the carrying capacity of the Earth will drop dramatically.  With such a dramatic and quick drop, mass starvation is likely to occur.  Another example is agriculture’s reliance on water.  As groundwater reservoirs are emptied, regions in the world become incapable of producing enough food.  This can already be seen in places like China where food production is declining due to an unsustainable amount of ground water being used.  If humans cannot find more sustainable methods of food production, system collapse due to starvation may be our most pressing concern to date.

Sources:

Bateson, Gregory (1972).  Effects of Conscious Purpose on Human Adaptation.  From steps to an Ecology of Min, pp 440-447. New York: Ballantine Books.

Wright, R. (2004). A Short History of Progress. Anansi Press.

http://www.cnn.com/2009/TECH/science/08/12/world.population/

http://www.cfr.org/china/china-vs-earth/p13233

http://www.un.org/esa/population/publications/popnews/Newsltr_87.pdf

http://news.bbc.co.uk/2/hi/in_depth/6496585.stm

http://www.un.org/esa/population/publications/wpm/wpm2001.pdf