Tunics and Elephants Crossing the Alps: Climate in Ancient Rome

Climate change affects so much more than political and economic interests — it touches people intimately and personally. This has led to the dissemination of readily accessible information online and on social media alongside scientists’ rigorous and complex research and findings. The only problem is that some of these posts are often unreliable, which has fueled doubt, skepticism and denialism. While there’s nothing wrong with non-experts trying to make sense of the wealth of knowledge about important climate change topics, it has increased the need for clarity and transparency in this work. This gave climatologist and meteorologist Giulio Betti the idea of bringing order to the chaos and oversimplifications that have diminished the public debate surrounding climate change in recent years. In a scientifically orthodox way, Betti uses simple and easy-to-understand language to discuss climate change. Think of his book as a guide for non-experts to orient themselves with the topic and defend against misinformation.

Editor’s Note: This and the following excerpts are taken from the book “It’s Always Been Hot! And Other Convenient Lies About Climate Change” by Giulio Betti, published by Aboca Edizioni, whom we thank. This week, the annual European State of the Climate report was released, confirming that 2024 was the hottest year on record for the continent — making this an especially fitting read.

Roman Tunics

From simple school textbooks to Hollywood blockbusters, whenever the Roman Empire is described, it is done by depicting gladiators, senators and common citizens dressed only in tunics and togas.

Beyond the obvious stylistic differences between men and women, these long garments indeed represented the most widespread clothing during the time of the ancient Romans. Not only were these seemingly light articles of clothing not exactly suited to withstand winter’s harshness neither were the common buildings during that time, such as temples, forums, domus and villas.

To some, this style of clothing and architecture was a sign that the climate 2,000 years ago in Rome, and much of Europe, was decidedly pleasant. After all, it’s hard nowadays to imagine someone walking through the Italian capital in the middle of winter wearing only a tunic. Homes today are heated and insulated, as are modern-day temples and forums — offices, churches, museums, shopping centers, etc. And even though Rome is certainly not famous for harsh winters — rather its mild climate — the view we have of it today is “colder” than the one conveyed by classical representation. This view has, over the years, fueled doubts about the exceptionality and uniqueness of today’s climate change, even leading some to claim that during Roman times it was warmer than it is today.

As is often the case, we are faced with a half-truth. To the distorted perception that comes from historical iconography, we must add objective data from scientific research. Between 200 BC and 150 AD (according to some scholars, even up to 400 AD), the climate in the Mediterranean area and much of the Euro-Atlantic region was rather stable and mild: we are talking about the period known as the “Roman Climatic Optimum.” In fact, much of the Imperial Age benefited from favorable climate conditions and drew great geopolitical and military advantages from them. But how favorable was it? 

Cross-analysis of the many available proxies (written chronicles, archaeological materials and natural samples) indicates that the weather was generally mild with rainy winters and overall cool summers. However, further investigations have also shown a certain variability within the period under consideration, with winters occasionally reaching freezing conditions (for example, in 177 BC, the Tiber River completely froze) and numerous floods in the first century AD. These also include frequent episodes of river-freezing in Central Europe (Rhine and Danube), as well as drought phases around 200 AD.

During the early Imperial period, summers in Europe were probably about 1 degree Celsius (1.8 degrees Fahrenheit) warmer than those in the mid-20th century (1950), and the cultivation of olive trees and vines in Italy extended further north.

We are dealing with a classic case in climatology: Within a generally favorable period, thermal variability is observed, caused by internal natural oscillations of the system, such as thermohaline currents like the Gulf Stream, El Niño and La Niña, increased or decreased snow area, volcanic eruptions and the influence of solar activity on certain weather circulations.