Drought ain't all that bad

So we've had a look at the main debates surrounding the Mayan collapse. Here I want to emphasize the central role complex societal-environmental interactions play in civilization collapse, the appreciation of which has become central to contemporary understandings of societal decline.

Lane et al (2014) combines proxy evidence taken from multiple reports relating to the Terminal Classic Period drought. The drought events experienced by the Mayans throughout their history is thought to have been caused by seasonal movements of the Inter Tropical Convergence Zone (ITCZ). Its southward movement results in dryer conditions of the Yucatan Peninsula, including the Mayan lowlands. Due to the global influence of the ITCZ, evidence of this southward movement can be found elsewhere, such as China, the Dominican Republic and the Lesser Antilles.

Map showing differences in position of ITCZ. Source: PNAS

Gypsum records and ostracod ­¹⁸0 level increases from Mexico, speleothems records from Guatemala and changes in Titanium concentrations from the Cariaco Basin all demonstrate a drought occurring in the Terminal Classic Period and indicate reduced precipitation levels over the Mayan lowland at this time. Despite this evidence of drought often being used to explain the collapse of the Mayans however, some very different responses close-by suggest that this may not be a suitable explanation.

Lane et al point out Caribbean populations would have experienced similar drought conditions to the Mayans. Although populations were not nearly the same size as the Mayan civilization, Caribbean populations responded positively to this climatic change. The Ostionoid culture increased agricultural production and subsequently experienced population growth. Populations in the Lesser Antilles also experienced a ‘dynamic period’ during which they expanded their territory and developed more sophisticated socio-political systems.

Map showing Yucatan Peninsula and Lesser Antilles. Source: GoogleMaps

The clear difference in response to the Terminal Classic Period drought illustrates the importance of societal response to a climate event. It’s important not to overlook the range of socio-political variables that are at play.

Some art from the Ostionoid culture. Source: National Museum of the American Indian

Armstrong (2014) supports this by stressing the point that collapse of any civilization is complex and it’s unlikely that a single factor would be the only cause. By analysing the pollen record taken from a lake sediment core from Guatemala, Armstrong concludes that drought caused a ‘chaotic spiral of adversities’. Armstrong summarizes that drought posed obstacles that the Maya could not overcome, which led to political instability and the breakdown of the social system. Here it is important to remember Lane et al.’s argument that socio-political factors are as important as drought in the success of a civilization’s response to climate change.

It would be difficult and pretty silly to try and argue that climate had no influence over the Mayan collapse. However we need to remember that other factors can prove to be just as important.

Before leaving the Mayans alone and moving onto the next case study, I’ll leave you with a quote from Armstrong: “The collapse of the Classic Maya empire functions as a warning to current and future generations: humans are not separate from the natural world but they are a part of it.”