Climate change

The late Bronze Age collapse of Mediterranean society and the role of catastrophic climate change events

Ancient climate events teach us about present-day climate change and its effects on vulnerable regions like the arid Mediterranean, requiring preparation and adaptation.


The Mediterranean Bronze Age was a time of many ancient mysteries, social dramas, and political intrigues. None has captured the collective imaginations of historians, archaeologists, and palaeoclimatologists more than the Late Bronze Age Collapse.

The Late Bronze Age Collapse was an interval occurring around 3,200 years ago when every major civilisation throughout the central and eastern Mediterranean region—from Italy and Greece, through Turkey and the Middle East, down to Egypt and parts of Northern Africa—experienced societal destabilisation, culminating in a near-simultaneous societal collapse event

Local and regional governments, Emperors and Kings, regional and interregional trade routes, and everything that was once orderly and urban ceased to exist. Even communities as small as towns were abandoned by the inhabitants as a huge movement of immigrants and refugees surged across the Mediterranean.

In Egypt, the rulers declared that the swaths of immigrants coming in from across Europe and the Near East were terrible warriors called “The Sea Peoples”. It was said that they came to ransack and destroy villages and towns, kill the men, steal the women, and leave nothing but ruin in their wake

In truth, however, the illusive “Sea Peoples” were likely colourful stories and historical myths, invented by the political leaders of Ancient Egypt to ensure their society was wholly against the outsiders, who were in actuality merely desperate refugees fleeing from the toppling Mediterranean empires and townships, abandoning their homes as entire societies, and civilisation itself, collapsed around them. Exactly why the Late Bronze Age Collapse occurred has been the subject of much debate among scientists, with a recent focus on Bronze Age climate change as the potential trigger. The theory is that as the climate become drier and more arid, the Mediterranean civilisations stopped being able to use agriculture to produce food for themselves and their livestock, freshwater sources ran dry, and a mass migration followed, all resulting in the cessation of the civilisations dependant on these basic needs.

An Ancient Mystery

In order to test the climate theory, a widespread review of all Bronze Age climate research was conducted, identifying 92 studies to examine in closer detail. All these datasets were tested against stringent criteria so that only the best were selected for further analyses. Of the original 92, the 24 climate records spread across the central and eastern Mediterranean with the most precise and accurate dating and the most detailed results were selected so that the final understanding would comprise only the highest quality data.

Figure 1. Location of sites providing palaeoclimate and archaeological records in the (a) eastern Mediterranean and (b) Levant. Credit: Calian Hazell (author)

Record types included cave stalagmite deposits, ocean and lake sediment cores, and terrestrial sediment outcrops. Stalagmites are records of anciently formed carbonates, which entrap within the molecules of carbon and oxygen that form them, precise values for local rainfall and temperature for anything up to a seasonal resolution over thousands of years. Sediment cores and outcrops are useful as they contain fossil pollen, showing us exactly which trees and plants thrived at specific times. As specific trees and plants live only under certain environmental conditions, the types and numbers present can tell us what the climate was like at the time. All of this climate data could then be directly compared to local archaeological sites in order to examine how societal shifts correlated with environmental changes.

Climate or Primate?

The results show that, while in some cases, archaeological collapse sites correlate with intervals of increasingly dry climatic shifts, this is not always the case. At some sites, increasingly arid conditions are met with no corresponding societal decline, while in some rare cases, climate reconstructions suggest more humid environmental conditions, and yet the archaeology still suggests societal abandonment of towns and cities. 

Most interestingly, several regional datasets suggest no consensus on wide-scale, synchronous climatic shifts. So, while we expected to see entire regions affected by climate change and become drier, such as in Greece and Turkey, this was not evident in the data.

Figure 2. Regional distribution of climate records analysed and the nature of climatic trends preceding and during the Late Bronze Age Collapse. Credit: Calian Hazell (author)
Note: Site markers are used to indicate the magnitude of change in a record (size of marker), duration of the shift towards increased aridity (shading), and closeness of the onset of increasing aridity to the collapse interval (shape). Hollow squares indicate no shift towards increased aridity is recorded 200 years before or during a collapse interval. Archaeological records are shown by stars, with white stars marking sites displaying societal expansion or unrestricted continuity. Black stars indicate major regions that experienced destruction/abandonment/contraction or a mixture of these events during the transition from the Late Bronze Age to the Iron Age (3180 – 3130 years ago).

It is likely that “societal resilience” to climate change, that is, how well individual communities could react and adapt to the changes they experienced over several generations, as well as the severity and speed of any change and how this impacted local level water availability, combined with other issues, such as how widely the climate effects influenced local trade and social networks, would create a plethora of incredibly complex and nuanced scenarios for Bronze Age peasants. 

While the large-scale empires, metropolises, and trade networks failed in their governance and administrative control, for most people, the effects of climatic events were governed by local adaptations, migrations, and voluntary cultural responses. The results support calls for a greater understanding of these underlying processes and a more holistic approach to studying the relations between climatic and societal shifts, as well as demonstrating the need for more high-resolution palaeoclimate records near archaeological sites to understand better the role of climate change in the dynamics of Mediterranean Bronze Age societies.

Great, But Who Cares??

So why exactly should we care about these ancient events? Today, we are all vulnerable to climate change, and arid regions are especially so. Should future climate change fail to adhere to the Paris 2015 Agreement, then the climate of the Mediterranean Basin will shift in a way not seen since the Late Bronze Age itself. 

Recent publications have shown that ecosystem alteration in the eastern Mediterranean may already have begun in response to climate variability. And it is not just the Mediterranean that faces this threat. To predict the wider implications of present-day climate change, it is crucial to understand the record of climate, environmental shifts and the effects of specific changes on human activities and societies of various forms and structures. 

This way, for the modern day, we can determine which environments in which regions are likely to react in which ways and plan various preparations, responses, and adaptations for yielding the best results under specific circumstances and scenarios. All thanks to history’s lessons, provided we continue to look, listen, and learn.


Journal reference

Hazell, C. J., Pound, M. J., & Hocking, E. P. (2022). High-resolution Bronze Age palaeoenvironmental change in the Eastern Mediterranean: exploring the links between climate and societies. Palynology46(4), 1-20.

Dr. Calian Hazel is currently employed as a Senior Laboratory Technician at the University of Northumbria in Newcastle. In 2020, he completed his doctoral thesis and was awarded a PhD in Earth & Environmental Sciences. Over the past nine years, he has acquired vast experience in various public-facing, supervisory, management, marketing, and teaching roles throughout his academic projects, making him highly skilled and transferable to different careers.