Archaeologically, this decline is indicated by the cessation of monumental inscriptions[3] and the reduction of large-scale architectural construction at the primary urban centers of the Classic Period.
[citation needed] Although termed a collapse, it did not mark the end of the Maya civilization but rather a shift away from the Southern Lowlands as a power center; the Northern Yucatán in particular prospered afterwards, although with very different artistic and architectural styles, and with much less use of monumental hieroglyphic writing.
In Quirigua, 49 kilometres (30 mi)[7] north of Copán, the last king Jade Sky began his rule between 895 and 900, and throughout the Maya area all kingdoms similarly fell around that time.
[8] A third piece of evidence of the progression of Maya decline, gathered by Ann Corinne Freter, Nancy Gonlin, and David Webster, uses a technique called obsidian hydration dating.
[citation needed] Another piece of evidence used by historians to date the Classic Mayan decline is the absence of architecture in the central Maya area after 830.
[10] From climate change to deforestation to lack of action by Maya kings, there is no universally accepted collapse theory, although drought has gained momentum in the first quarter of the 21st century as the leading explanation, as more scientific studies are conducted.
A study by anthropologist Elliot M. Abrams came to the conclusion that buildings, specifically in Copán, did not require an extensive amount of time and workers to construct.
[citation needed] It has been hypothesized that the decline of the Maya is related to the collapse of their intricate trade systems, especially those connected to the central Mexican city of Teotihuacán.
Widespread disease could explain some rapid depopulation, both directly through the spread of infection itself and indirectly as an inhibition to recovery over the long run.
Shimkin specifically suggests that the Maya may have encountered endemic infections related to American trypanosomiasis, Ascaris, and some enteropathogens that cause acute diarrheal illness.
Paleoclimatologists have discovered abundant evidence that prolonged droughts occurred in the Yucatán Peninsula and Petén Basin areas during the Terminal Classic.
[23] In 1995, Hodell, Curtis, and Brenner published a paleoclimate record from Lake Chichancanab on the Yucatán Peninsula that showed an intense, protracted drought occurred in the 9th century AD and coincided with the Classic Maya collapse.
[25] The drought theory provides a comprehensive explanation, because non-environmental and cultural factors (excessive warfare, foreign invasion, peasant revolt, less trade, etc.)
[27] The role of drought in the collapse of Classic Maya civilization has remained controversial, however, largely because the majority of paleoclimate records only provide qualitative data, for example whether conditions were simply "wetter" or "drier".
The lack of quantitative data makes it difficult to predict how climatic changes would have affected human populations and the environment in which they lived.
This quantitative climate data can be used to better predict how these drought conditions may have affected agriculture, including yields of the Maya's staple crops, such as maize.
[31] Other critics of the megadrought theory, including David Webster, note that much of the evidence of drought comes from the northern Yucatán and not the southern part of the peninsula, where Classic Maya civilization flourished.
"[39] In a separate publication, Weiss illustrates an emerging understanding of scientists: Within the past five years new tools and new data for archaeologists, climatologists, and historians have brought us to the edge of a new era in the study of global and hemispheric climate change and its cultural impacts.
The climate of the Holocene, previously assumed static, now displays a surprising dynamism, which has affected the agricultural bases of pre-industrial societies.
Instead, it is likely that multiple mechanisms were involved,[31] including solar variability,[41] shifts in the position of the Intertropical Convergence Zone,[42] changes in tropical cyclone frequency[28] and deforestation.
[43] The exceptional accomplishments of the Maya are even more remarkable because of their engineered response to the fundamental environmental difficulty of relying upon rainwater rather than permanent sources of water.
Intensive agricultural methods were developed and utilized by all the Mesoamerican cultures to boost their food production and give them a competitive advantage over less skillful peoples.
[48] The agricultural techniques utilized by the Maya were entirely dependent upon ample supplies of water, lending credit to the drought theory of collapse.