Severe drought may have ended an empire 3,000 years ago, study claims

Hittites were one of the most prominent civilizations in central Anatolia around the 1300s BC. A recent study published today has shown that a devastating drought in 1198–1196 contributed to the end of the Hittite empire.

The study's lead author Sturt W. Manning and his team worked on whether a similar climate change event could bring the end of the Hittites, as did to other Bronz Age civilizations.

As per the study, thinner tree rings indicate drier years since less water typically results in slower tree growth. Secondly, using a technique called carbon-13 stable-isotope analysis on tree samples, it is possible to pinpoint drier periods by looking for higher-than-average levels of 13C, which is a gauge of the relative abundance of 13C to 12C isotopes in the samples.

The authors also looked at samples for cellular structural alterations in severe drought. The results from these data types were correlated, and Manning and the team could compare them to the continuous annual historical sequence of Gordion tree rings.

It was drier than average

According to the authors' findings, the thirteenth and tenth centuries BC were drier than average, and the years 1198–1196 BC had a severe three–year drought. These dates are intimately related to the Hittite Empire and correlate to the turbulent time documented towards the end of the Bronze Age.

The authors emphasized how dry and prone to drought central Anatolia was. As shown by the enormous grain silos that were a common sight in central Hittite cities and the development of extensive water infrastructure projects, such as dams, that picked up steam in the thirteenth century BC, communities living in such landscapes developed coping mechanisms for the years with inadequate rainfall.

The abandonment of Hattusa (capital) during the latter decades of the Hittite Empire is one of the numerous mysteries of Hittite research. The causes for Hattusa's abandonment have been discussed in the absence of archaeological evidence supporting the city's destruction by battle or conquest, with climatic change and the ensuing droughts and famines being one of the contenders.

The study was published in Nature.

Study abstract:

The potential of climate change to substantially alter human history is a pressing concern, but the specific effects of different types of climate change remain unknown. This question can be addressed using palaeoclimatic and archaeological data. For instance, a 300-year, low-frequency shift to drier, cooler climate conditions around 1200 bc is frequently associated with the collapse of several ancient civilizations in the Eastern Mediterranean and Near East1–4. However, the precise details of synchronized climate and human-history-scale associations are lacking. The archaeological–historical record contains multiple instances of human societies successfully adapting to low-frequency climate change5–7. It is likely that consecutive multi-year occurrences of rare, unexpected extreme climatic events may push a population beyond adaptation and centuries-old resilience practices5,7–10. Here we examine the collapse of the Hittite Empire around 1200 bc. The Hittites were one of the great powers in the ancient world across five centuries11–14, with an empire centred in a semi-arid region in Anatolia with political and socioeconomic interconnections throughout the ancient Near East and Eastern Mediterranean, which for a long time proved resilient despite facing regular and intersecting sociopolitical, economic and environmental challenges. Examination of ring width and stable isotope records obtained from contemporary juniper trees in central Anatolia provides a high-resolution dryness record. This analysis identifies an unusually severe continuous dry period from around 1198 to 1196 (±3) bc, potentially indicating a tipping point, and signals the type of episode that can overwhelm contemporary risk-buffering practices.