Why did the Classic Maya cities decline?

The decline of the Classic Maya lowland cities, mostly between the eighth and eleventh centuries CE, is usually attributed to several overlapping factors rather than one. A summary at worldhistory.org says historians have generally settled on a combination of warfare between city-states, and drought, among main factors, and notes these were not always found together in a single city. The weight given to drought is the main point of disagreement. [1]

Paleoclimatologists have found abundant evidence that droughts coincided with the collapse. A review in Annual Reviews compiles climate proxy data indicating that droughts from the ninth to eleventh century were the most severe and frequent in Maya prehistory. Its authors conclude that drought clearly contributed to the unusual severity of the collapse and helped prevent the kind of recovery seen after earlier setbacks. In the drier northern lowlands, a later political collapse around 1000 CE appears linked to ongoing extreme drought. [2]

One explanation concerns water. The PAGES article describes the Elevated Interior Region, including Tikal and Caracol, as far above perennial water sources. The Maya built reservoirs there and tended to overbuild them to cope with variable rainfall, but such systems may not have survived severe drought. Drought could have led to crop failure, famine and refugees, and then to rejection of rulers, warfare or shifting trade routes. [3]

Many archaeologists maintain that drought cannot explain the timing or the complex nature of the changes. The Annual Reviews article itself notes that archaeological evidence points to an earlier start for the economic and political processes that broke up states in the southern lowlands, before the major droughts. The PAGES article similarly says that, although droughts are well documented in several periods, the archaeological evidence for collapse in those periods remains coincidental. [2] [3]

Lidar research in the Western Maya Lowlands, led by Charles Golden of Brandeis and Andrew Scherer of Brown, found terraces and drainage channels in rural communities around La Mar, suggesting people there grew more than enough food. Hilltop forts point to ongoing conflict between kingdoms. Golden said the Maya probably did not collapse because of a drought, and that even if drought was a significant problem, communities faced it in different ways. [4]

A modeling study published in PMC links dry conditions to the growth of Classic cities and to warfare, which peaked in the seventh century when urbanization was at its height. It argues that the process then ran in reverse. In the Terminal Classic, the climate was favorable for rural dry farming, warfare was declining, farmland around cities had been degraded by canopy and soil loss, and agricultural infrastructure was falling into decline. At a tipping point, urban residents would have gained by leaving or by forcing concessions from elites. Postclassic cities were less hierarchical and lacked the Classic kingship systems. The authors also mention possible food insecurity, disease and outmigration. [5]

A Smith College resource adds that deforestation likely made the natural droughts worse, and that crop failure may have raised tensions between city-states. [6]