Mural from Bomapak Mexico
It should be pointed out that Collapse while rare is not unique it has happened to a number of societies in the course of Human History. For example:
1, The Western Roman Empire 350-500 C.E.
Since Stephens and Catherwood explored and described the Mayan cities there has been much speculation about why the cities were abandoned, much of it totally useless. Unfortunately the Maya seem to attract more then their fair share of weirdoes and cranks. Including a truly large number of the wacky who could not and cannot believe that the ancestors of today’s Maya built the cities. The Erich von Daniken Chariots of the Gods, nonsense for example. Who is mentioned here because von Daniken interprets the image on Pacal’s sarcophagus lid as that of an Astronaut in a spaceship. I wonder what Pacal would think? Mr. Von Daniken’s particular conceit is that the Mayans were expecting the "Gods" to return on a certain date and when they did not the Mayans abandoned their cities.2
To get back to reality theories about why the Mayan collapse happened have included, Earthquakes, Famines, Epidemics, Hurricanes, Unbalanced sex-ratios, Foreign invasions and so on and so forth. All the above theories have in common the following. Lack of evidence, wild speculation and simplicity.3 They are also almost all not just partly wrong but completely wrong.4
Rather more serious is the idea proposed by the Great Mayanologist Sylvanus Morley that the Mayans devastated their environment by practicing slash and burn agriculture that turned large areas of the lowlands into savanna leading to collapse due to inability of agriculture to support the population.5
The Great Mayanologist Erich Thompson proposed that the Collapse occurred when exasperated Mayan peasants, tired of taxes and wars, overthrew the system and sacked the cities.6
Both those theories are believed to have some truth in them however both had a series of flaws. Morley’s Agricultural depletion theory was based on the assumption that the Mayans during the Classic period practiced slash and burn agriculture, (also called swidden and milpa), which involved burning down an area of jungle planting 1-3 crops and then letting it lie fallow for years (10-30) before planting again. Of course the population that could be supported by this system was not large and population densities were assumed to be low and the cities assumed to be ceremonial centres. To put it bluntly this is all wrong. The Mayan region was much more thickly populated, the cities real cities, and intensive agriculture by means of terrace farming and irrigation the norm in the lowlands.7
Regarding the peasant revolt theory it was based on a view of Mayan society has a huge mass of peasant labourers ruled by a tiny class of Aristocrats/Priests residing in ceremonial centres. This is also very wrong. We now know about the existence of a large class of "petty" nobility with a far from insignificant "middle" class. And of course the cities had large populations.8
The lack of evidence for either savanna creation or a mass peasant revolt does not help these theories either.9 This does not mean these theories do not have value. The decipherment of the Glyphs has brought to forth various new theories and the creation of new theories. The following are some things to keep in mind.
Lintel from Yaxchilan Mexico
1, Mayan cities had been abandoned before the best example of this is El Mirador about 100 C.E.
2, The Maya had cyclical view of time expecting things to repeat, at least on a general level each 256 years of the short count.
3, There are clear signs of environmental degradation and population pressure before the collapse.
5, The population did not collapse and did not decline noticeably until several centuries after the collapse.
6, The Maya Collapse is similar to other collapses.10
It now appears that the collapse occurred for a variety of interrelated reasons. The most likely reasons seem to be a combination of environmental degradation and severe competition between the city-states.
It has been suggested that the concept "marginal returns " offers a way of looking at the problem. In marginal returns the idea is for example: 1X effort = 1Z result, however,2X effort = 1 & 1/2 result, not 2Z result. Or to put it another way it costs for example:it costs $100 to build a bridge 10 meters long, however it costs, $300 to build a bridge 20 meters long. The idea is that all systems have "costs" which tend to go up exponentially in relation to their results. Thus a pyramid 40 meters high takes 4 times the effort, cost, etc., of one 50 20 meters high. This applies to all "systems". The "marginal return" tends to get less. In other words you get less bang for your buck the more you try to do. In this concept has Mayan society got more complex, more ornate, has more temples were built, the aristocracy got larger there was a tendency to get less for the effort, cost, in maintaining the whole system. The idea is that in the late 8th century the cost became to great in relation to the returns, and the system radically simplified i.e., collapsed. 11
The Mayan agricultural system of irrigation and terrace agriculture was apparently developed to support a growing population and to provide the economic surplus to support the elite and the cities. For a considerable period of time the system continued to expand fueled by demand for more people for building projects, pay taxes and to provide bodies for intercity competition. In the late 8th century the system was capable of supporting the population but it was having increasing difficulty doing that and supporting the cities. It was the apparent impossibility of doing both by about 800 C.E. that caused the collapse. Certainly there is some evidence of increasing hunger and disease by the late 8th century. Also it appears that the elite was much larger by the late 8th century than before and a greater burden to carry. Further building projects were on average more extravagant/costly than ever. Wars between the city-states were getting worst. 12
Also the system had been under stress for quite sum time because of the inability of the Maya to politically unify resulting in continual wars between the cities. By 400 C.E., the Mayan world was dominated by two "Super" states Kalak’mul and Tikal (Mutul). Each one lead a constellation of vassals and allies who acknowledged the over lordship of one or the other "Super" state. The conflict was never resolved instead both alliances fought themselves into exhaustion. The competition lead to escalating conflict, competition and steadily increasing expense and effort. The result was that beginning in the late 8th century a great simplification began to happen. 13.
For example in Copan the local nobles apparently decided they did not need a King or monumental architecture or the expense of Royal politics and after Yax-Pac died (820 C.E.) made sure they did not have one. In Bonampak the locals may have overthrown the government. In other place like Dos Pilas, Aguateca ex-victims sacked and destroyed them both. In other places the inhabitants simply abandoned the city i.e., Yaxchilan, Palenque. In some places like Kalak’mul the place was occupied for several decades after the collapse but then abandoned. In many place temporary smaller centres were established independent from any control has the city-states disintegrated before they too collapsed. 14
The Maya in the Classic age also apparently knew of and used the short count dating system which placed a date within a 256 recurring period of time. The Maya believed that events in a general sense repeated themselves in each 256-time period. Thus for example Tikal (Mutul) was defeated and sacked by Caracol in 562 C.E.. The katun (20 year period) in which this disaster happened was due to start c. 800 C.E.. The "Hiatus" that resulted from the sack lasted in Tikal and many of its allies for over 100 years. With that date approaching it is possible that many Maya acted accordingly and created, to some extent, a self-fulfilling prophecy?16
In the end the cities were abandoned and left to the jungle while the Maya were left to pick up the pieces for the cost of maintaining a steady escalating complex, expensive system was too much, and besides was not disaster inevitable?
What is remarkable is that it is all too likely that the Maya may have something to teach us about the limits to "endless" growth.
Glyphic Panel from Palenque Mexico