Digging deep: Cooking pots reveal how ancient megacity died out because of climate change

Excavation in the North Shelter at Çatalhöyük. Jason Quinlan and the Çatalhöyük Research Project

Polish archaeologists have discovered how one of the world’s first megacities came to a sticky end, by studying the inhabitants’ dirty pots.

Five scientists from universities in Poznań and Gdańsk were part of an international team that took animal fat residue from ceramic pots used by residents of the ancient Neolithic city of Çatalhöyük in southern Turkey.

This revealed that dramatic climate change and drought led to the rapid decline of the ancient honeycomb city around 8000 years ago.

Scientists had suspected for some time that a major event way back in the murky past brought an end to this ancient civilisation. It’s well known that about 8,200 years ago, in what is today Canada, a post-glacial lake filled up with fresh water from a melting glacier, which then flooded out into the Atlantic.

This big splash was so dramatic that it caused a fall in temperatures coupled with drought throughout the northern hemisphere, the effects of which left traces, for example in tree rings.

Archaeologists studying Çatalhöyük knew that at around the same time the community suffered a deep crisis, causing residents to flee to western Anatolia and today’s Greece and Bulgaria.

They couldn’t be sure, though, what actually caused the decline of the megacity. This is where the Poles stepped in, who found evidence of climate change and drought in animal fat deposited on the porous internal walls of ceramic pots.

Over the last few digging seasons in the Polish sector at Çatalhöyük, Professor Marciniak from the Institute of Archaeology at the Adam Mickiewicz University and his team have dug up about 13,000 pottery shards, 87 of which were qualified as coming from the right time and containing animal fats.

They were sent to Bristol where researchers used gas chromatography and mass spectrometry to identify hydrogen isotopes.

The results showed that the ancient shards contained high levels of deuterium, a type of heavy hydrogen. It is known that deuterium increases in plants during droughts and this showed up in the fats of animals that had eaten plants in Çatalhöyük.

The research is pioneering because this is the first time that shards from cooking pots have been used to obtain data and it opens the door to new research using ceramic to reconstruct the climate in ancient societies.

The vast archaeological site of Çatalhöyük is a very rare example of a well-preserved Neolithic settlement and is a key site for understanding human prehistory.

The city had no streets, and houses were clustered in honeycomb formations. With no front door to speak of, residents would enter their homes through holes in the ceiling.

Inside many of the homes, wall murals and reliefs have been discovered that represent the symbolic world of the inhabitants.

Strange features of the site include a complete lack of any public buildings, suggesting that their society was organised in a completely different way to what we are familiar with today.

Residents would bury their relatives under their living rooms and sometimes remove their skulls and paint them red.

The biggest puzzle are the tens of thousands of fired clay balls just big enough to fit in a hand. Theories for their use range from cooking aids to weapons or even a form of currency or accounting system.

Polish archaeologists have been working at the site for a long time and have made some fascinating discoveries over the years.

In 2016, the same team found stone figurines representing two corpulent women. The discovery was significant because the figures were larger than others that had been found previously and they were discovered in situ, rather than in an ancient dump site, exactly as their owners had left them.