Cahokia Study Reveals Impacts of Climate Change on Human History

Related Articles

Related Articles

Water and air are highly mutable resources that exist in a myriad of physical states and dimensions, and due to their affectivity, these entities participate in a multitude of interactions capable of sustaining life, transforming environments, and shaping human behavior.

As air and water circulate between the atmosphere and the landscape through the process of evapotranspiration, humans interact with and form relationships–or bio-cultural associations–with these substances. Facets of human life, like breathing, cooking, bathing, agriculture, and engaging with the outdoors, become intertwined with a region’s hydroclimate. Interactions with air and water, in turn, influence the ways humans construct and modify their societies.

As the climate shifts, bio-cultural associations are often altered in the process. Archaeologists analyze the impacts of climate change on human history and have frequently identified correlations between the Medieval Climate Optimum–spanning from the 9th century to the 13th century–and periods of societal change.


Taking this correlation into account, Timothy R. Pauketat, in the article “When the Rains Stopped: Evapotranspiration and Ontology at Ancient Cahokia,” published in the Journal of Anthropological Research, explores how the trajectory of the Medieval Climate Optimum (MCO) aligns with the history of Greater Cahokia–an ancient indigenous city in the Mississippi River valley. By analyzing air flow and precipitation levels during the MCO, Pauketat examines how evapotranspiration shaped life in the Mississippi valley and argues it played a critical role in determining the progression of Cahokian urbanism. In particular, Pauketat focuses on the fluctuating popularity of an institutionalized form of evapotranspiration–a sacred rite referred to as “Steam Bath Ceremonialism” (SBC).

Utilizing an ontological approach that emphasizes relationships between human and non-human entities, Pauketat elaborates on how the river basin’s weather extremes and strong storms were interpreted as spiritual transfers of power from the atmosphere to humanity. Steam Bath Ceremonialism presents another example of transferring powerful energy. In this transubstantiation ritual, liquid water was converted into steam, and those in attendance absorbed the steam and its healing energy. While circular Cahokian steam baths initially could only be found at a few sites, medicine bundle transfers enabled the spread of steam baths to smaller, rural regions.

Widespread acceptance of Steam Bath Ceremonialism was one of many changes in Greater Cahokia during a period of urbanization Pauketat has designated as the city’s “Big Bang.” Around 1050 CE, new architectural styles and elements–particularly ones associated with water or lunar cycles–were embraced as the city was planned according to a precinct grid and as older villages were replaced by mounds, plazas, cypress post arrangements, religious buildings, and borrow pits. Shrines were expanded, and causeways were constructed to establish pathways to mounds with steam baths.

While Greater Cahokia was accustomed to substantial amounts of rainfall, PDSI models reveal a hydroclimatic shift throughout the 12th century, resulting in less rainfall and progressively drier conditions. Pauketat suggests the reduction in precipitation served as a catalyst for dramatic changes, such as the migration of farmers, the construction of defensive barriers, the concealment of food supplies, and the decline of Steam Bath Ceremonialism.


Image Credit : Prayitno

Download the HeritageDaily mobile application on iOS and Android

More on this topic


Study Sheds New Light on the Behaviour of the Giant Carnivorous Dinosaur Spinosaurus

New research from Queen Mary University of London and the University of Maryland, has reignited the debate around the behaviour of the giant dinosaur Spinosaurus.

New Skull of Tube-Crested Dinosaur Reveals Evolution of Bizarre Crest

The first new skull of a rare species of the dinosaur Parasaurolophus (recognized by the large hollow tube that grows on its head) discovered in 97 years.

Women Influenced Coevolution of Dogs and Humans

In a cross-cultural analysis, Washington State University researchers found several factors may have played a role in building the mutually beneficial relationship between humans and dogs, including temperature, hunting and surprisingly - gender.

Dinosaur Embryo Helps Crack Baby Tyrannosaur Mystery

They are among the largest predators ever to walk the Earth, but experts have discovered that some baby tyrannosaurs were only the size of a Border Collie dog when they took their first steps.

First People to Enter the Americas Likely Did so With Their Dogs

The first people to settle in the Americas likely brought their own canine companions with them, according to new research which sheds more light on the origin of dogs.

Climate Change in Antiquity: Mass Emigration Due to Water Scarcity

The absence of monsoon rains at the source of the Nile was the cause of migrations and the demise of entire settlements in the late Roman province of Egypt.

Archaeologists Discover Bas-Relief of Golden Eagle at Aztec Templo Mayor

A team of archaeologists from the Instituto Nacional de Antropologia e Historia (INAH) have announced the discovery of a bas-relief depicting an American golden eagle (aquila chrysaetos canadensis).

Lost Alaskan Fort of the Tlingit Discovered

Researchers from Cornell University and the National Park Service have discovered the remnants of a wooden fort in Alaska – the Tlingit people’s last physical bulwark against Russian colonisation forces in 1804.

Popular stories

Exploring the Stonehenge Landscape

The Stonehenge Landscape contains over 400 ancient sites, that includes burial mounds known as barrows, Woodhenge, the Durrington Walls, the Stonehenge Cursus, the Avenue, and surrounds the monument of Stonehenge which is managed by English Heritage.

The Iron Age Tribes of Britain

The British Iron Age is a conventional name to describe the independent Iron Age cultures that inhabited the mainland and smaller islands of present-day Britain.

The Roman Conquest of Wales

The conquest of Wales began in either AD 47 or 48, following the landing of Roman forces in Britannia sent by Emperor Claudius in AD 43.

Vallum Antonini – The Antonine Wall

The Antonine Wall (Vallum Antonini) was a defensive wall built by the Romans in present-day Scotland, that ran for 39 miles between the Firth of Forth, and the Firth of Clyde (west of Edinburgh along the central belt).