Sources included diaries, travel notes, parish or monastery registers, and other written documents. Credit: Gaceu et al, 2024.

500-year-old Transylvanian diaries show how the Little Ice Age completely changed life and death in the region.

Tapping into ‘society’s archive’, researchers have examined written sources from the 16th Century that chronicle famine, excessive flooding, and plagues in what today is Romania.

Glaciers, sediments, and pollen can be used to reconstruct the climate of the past.

But beyond ‘nature’s archive’, other sources, such as diaries, travel notes, parish or monastery registers, and other written documents – known at the ‘society’s archive’ – contain reports and observations about local climates in bygone centuries.

The Transylvanian diaries tell of a particularly hot and dry first half of the century.

Tudor Caciora, a doctorate student and research assistant at the University of Oradea said: “One compelling passage comes from a historical document describing the summer of 1540; ‘The springs dried up, and the rivers dwindled to mere trickles. Livestock fell in the fields, and the air was thick with despair as the people gathered in processions, praying for rain.’

“This vivid account underscores the emotional and spiritual dimensions of living through climatic extremes.”

In contrast, the second half of the century was characterised by heavy rainfall and floods, particularly in the 1590s.

The ‘society’s archive’ – contain reports and observations about local climates in bygone centuries. Credit: Gaceu et al, 2024.

Delayed ice age

Compared to the western parts of the European continent, which cooled significantly when in the 16th Century a period known as the ‘Little Ice Age’, intensified.

During the second half of the century, temperatures dropped by 0.5°C.

In Transylvania, however, hot weather was recorded much more frequently than cold weather during the 16th Century.

Caciora said: “This makes us believe that the Little Ice Age could have manifested itself later in this part of Europe.”

Later writings, in which more cold waves and severe winters are mentioned, support this thesis.

Chronicles and diaries revealed how people perceived, responded to, and were impacted by severe weather events. Credit: Gaceu et al, 2024.

Climate catastrophes

Such weather variations often resulted in catastrophes, related directly or indirectly to the climate.

These included 30 years during which the Black Death ravaged the land, 23 years of famine, and nine years during which locust invasions were recorded.

However tragic, weather extremes and resulting calamities could have driven changes in settlement patterns, the researchers said.

Caciora said: “Towns might have adopted flood-resistant infrastructure or migrated to more favourable areas.

“The challenges might also have spurred technological innovations, such as improved irrigation systems or storage facilities.”

The human element

Caciora advised: “Chronicles and diaries reveal how people perceived, responded to, and were impacted by these events.”

Despite the insights it provides, the study faces several limitations, the researchers pointed out. Few people were literate, reports are often subjective, or only true on local scales.

In addition, the records are fragmented. For example, the researchers were not able to include any records about 15 years of the 16th Century, either because no records existed, or they were too contradictory for inclusion.  

Nevertheless, these writings not only provide a glimpse into how people in the past might have lived, but are also relevant for modern climate resilience strategies, particularly in understanding the socio-economic consequences of extreme weather events and their role in shaping human history.

Caciora said: “Studying climate records from the society’s archive is as crucial as analysing natural proxies.

“It provides a human-centric perspective on past climatic events.”

The research is published in Frontiers in Climate.