Title: The abandonment of classic Maya cities.
Statement: The abandonment of classic Maya cities was caused mainly by a catastrophic drought.

Argument 1: Paleo-climate studies show a serious drought at the end of the Classic period. (Hoddel, D.A., J.H. Curtis and M. Brenner, 1995: "Possible Role of Climate in the Collapse of the Classic Maya Civilization", Nature 375: 391-394.)
Argument 2: Water supplies are scarce in the rainforest and insufficient to cope with a long drought.
Argument 3: The survival of the cities was based on an intensive agriculture that required a regular water supply.
Argument 4: Large populations could not have been maintained with a drastic reduction of food supplies.
Argument 5: The elite residing in the cities was dependant on food tribute for its subsistence.
Argument 6: A drought would have motivated people not involved in food production to abandon the cities.
Argument 7: Such a catastrophy would have caused tensions among social classes leading to a dissolution of the social structure.

The abandonment of classic Maya cities was caused mainly by a catastrophic drought. Paleo-climate studies show a serious drought at the end of the Classic period (Hoddel, Curtis & Brenner, 1995). Water supplies are scarce in the rainforest and probably insufficient to cope with a long drought. The survival of the cities was based on an intensive agriculture that required a regular water supply. Large populations could not have been maintained with a drastic reduction of food supplies. The elite residing in the cities was dependant on food tribute for its subsistence. A drought would have motivated people not involved in food production to abandon the cities. Such a catastrophy would have caused tensions among social classes leading to a dissolution of the social structure.