Some of the primary source documents in this new study include travel notes, diaries, and parish or monastery records. Gaceu et al., 2024ShareWith centuries old primary source documents, a team of researchers in Romania are exploring how a region best known for vampire legends was drastically altered by the effects of the Little Ice Age. This period of colder than usual temperatures from the early 14th century CE to the mid-19th is known for major social upheaval, famine, and plague. According to these first person accounts, geographical regions of the continent also appear to have experienced major weather changes at different times and humanity responded. The findings are detailed in a study published February 12 in the journal Frontiers in Climate. Get the Popular Science newsletter Breakthroughs, discoveries, and DIY tips sent every weekday. By signing up you agree to our Terms of Service and Privacy Policy.What was the Little Ice Age?The Little Ice Age was a period of global cooling that began during around 1300 CE and lasted until about 1850. Average temperatures in the Northern Hemisphere dropped by about 1.1 degrees Fahrenheit.Scientists are still not certain what phenomenon caused the Little Ice Age. Reduced solar output, changes in the circulation of the atmosphere, and increased volcanism on Earth may have played a role.Mountain glaciers expanded in several locations across Europe, North and South America, and Oceania. Famine was widespread, as crops failed due to the cold. Social uprisingsand even witch trailsincreased in response to the weather-induced devastation.Natures archive vs. societys archiveTo piece together Earths history from this time, scientists can use ice cores, sediment samples, and pollen. This natural archive can tell us a fair amount about sea levels, temperature history, storms, glacier positioning, and more.Societys archivewritten reports and observations about local climates or chiseled warnings like hunger stonescan help corroborate what natures archive says.In this new study, a team used documents from people who lived in present day Transylvania during the 16th century CE.The societys archive contains reports and observations about local climates in bygone centuries. CREDIT: Gaceu et al., 2024. We show that the climate was marked by significant variability, including prolonged periods of drought, heatwaves, and episodes of intense rainfall and flooding, Tudor Caciora, a study co-author and geographer at the University of Oradea in Romania, said in a statement. The study illustrates the complex interplay between heat waves, droughts, floods, and their cascading impacts on agriculture, public health, and societal stability, emphasizing the significant role of climate in shaping human history.From the documents, it appears that the first half of the 16th century was particularly hot and dry. A passage describing the summer of 1540 reads: 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, said Caciora.The second half of the 16th century saw heavy rainfall and flooding, particularly during the 1590s. Other parts of Europe were still cooling significantly when the Little Ice Ages effects began to intensify and temperatures dropped. However, hot weather was recorded much more frequently than colder weather in 16th century Transylvania.This makes us believe that the Little Ice Age could have manifested itself later in this part of Europe, said Caciora.Additionally, some later writings describing severe winters and cold waves support this thesis.Through human eyesThese weather variations often resulted in major catastrophes including the Black Death, numerous famines, and locust invasions that were directly and indirectly related to climate.The team believes that these weather extremes and the resulting upheaval could have driven changes in settlement patterns.Chronicles and diaries revealed how people perceived, responded to, and were impacted by severe weather events. CREDIT: Gaceu et al., 2024. Towns might have adopted flood-resistant infrastructure or migrated to more favorable areas. The challenges might also have spurred technological innovations, such as improved irrigation systems or storage facilities, said Caciora.While the diaries do reveal how people understood and responded to these impactful events, there are several limitations with this study. Not many people at this time could read or write, records can be fragmented, and reports are often subjective and on a local scale so we are not getting a very holistic view of the time.[ Related: Shifting ancient climates shaped human evolution. ]These writings still provide scientists with a glimpse of the socio-economic consequences of extreme weather events and how they have constantly shaped human history.Studying climate records from the societys archive is as crucial as analyzing natural proxies, said Caciora. It provides a human-centric perspective on past climatic events.