Since the late 1990s, John Haldon, the Shelby Cullom Davis ’30 Professor of European History and professor of history and Hellenic studies, Emeritus, has been working with scientists to answer questions about the medieval period in Anatolia (in present-day Turkey), such as how people moved around or produced food. 

After coming to Princeton in 2005, he developed an archeological field project in Turkey with the aim of answering some of these earlier research questions. The project surveyed the landscape developed in the medieval period, and by doing so, delved into environmental and climate history. 

“Environmental history has become quite topical and popular; the problem is that historians don’t always understand the scientific data that they are wielding,” said Haldon. “[Historians] read articles by scientists and extract from these articles certain conclusions upon which they build a historical argument. As it turns out, the conclusions they are basing their history on are often challenged by other scientists themselves.”

From his conversations with scientist colleagues, Haldon realized that this was a problem for scientists, as well. “By assuming that historians are working with detailed positive knowledge, scientists are building arguments about things like global warming based on the same sort of misreading of historians' work.”

In 2015, Haldon sat down with several graduate students and international colleagues to come up with a project that aimed to bridge the misunderstandings between historians and scientists. “We wanted to do what no one else had done successfully: to build a specialized team that wouldn't just work virtually, but would meet regularly and work together in a constructive and integrative way to further each other’s research.”

The Climate Change and History Research Initiative, which brings archaeologists, historians and paleo-environmental scientists together to understand the impact of climate on complex societies in Eurasia from 300 to 1900 C.E., was born out of these discussions.

The first CCHRI meeting convened in 2015 with the sole agenda of talking to each other without misunderstanding. One of the key issues the group addressed in its inaugural meeting was scale. “We had to find a way to make sure each of our scales were commensurate with one another,” said Haldon. “An entire civilization can come and go in 600 years, but in geological time, 600 years is the blink of an eye.”

Since its first meeting, the group “hasn’t looked back.” The CCHRI continues to meet semiannually to study the interactions between the environment and climate in historical societies. Lee Mordechai, senior lecturer in ancient history at the Hebrew University of Jerusalem, said: “The interdisciplinary approach here is beneficial since it unlocks new types of independent evidence we can use to cross-validate the results of our analysis. Broadly, we can now look for ‘signatures’ of past environmental and climate change in historical sources, archaeological data, paleoclimate proxies, and seismic or climate models, and try to understand how past societies interacted with their environments over time.”

Many of the findings of these meetings have been published, most recently in a special issue of the journal Human Ecology, the Proceedings of the National Academy of Sciences of the USA and – forthcoming – in historical journals such as Past and Present or Annales. The group is planning a book series, “Princeton Studies in Climate, Environment and History” with the Oxford University Press, which they hope to launch this fall. They are also working on an app for the scholarly research of the Justinianic Plague.

In addition to its semiannual meetings, the CCHRI brings guest speakers to Princeton’s campus to discuss different aspects of the climate, environment and society in Eurasia from 300-1900 C.E.

The CCHRI also runs introductory training workshops for junior faculty, graduate students and postdocs who work in archaeology and history. According to Haldon, the aim of these workshops is “to introduce early-career scholars to the paleo sciences and to learn how not to misuse and abuse the sciences” by demonstrating how specialists use scientific techniques — such as dating speleothems and ice cores — to determine things like atmospherics and industrial production in the past.

“You can do a huge amount [with scientific techniques], but you have to know how to use them it carefully because there are big disagreements among the scientific community themselves about how to date some of this stuff,” said Haldon.  

The fourth and most recent of these training workshops, “History, Environment and Climate,” was held at the Princeton Athens Center this past March.

“I was very glad to see the high attendance and interest in the workshop among our Greek colleagues – the entire room was packed throughout the two days!” said Mordechai. “I also established new connections and came up with ideas for future projects.”