[Kim Byungmin's Science Village] The Fall of the Roman Empire Was Caused Not Only by Lead Poisoning but Also by Climate Change

Kim Byung-min, Science Writer

Who are you listening to for stories about the world?

By chance, I came across a short video about the fall of Rome on the internet. It was probably not just by chance but exposed by an algorithm. The trigger was likely my recent interest in world history and searching online. Such features of seemingly convenient platforms can sometimes feel uncomfortable. There is also a fear that even our interests, which seem like free will, are recorded, and we cannot be sure whether the information shown is trustworthy.

The YouTuber defined lead poisoning as both a cause and consequence of Rome’s fall and delivered the story with witty eloquence that was quite captivating. It made me think that if I were to give a lecture, I should do it this way. It is well known that Rome had an urban engineering system with water supply and sewage pipelines, and environmental control worked meaningfully. However, it was revealed that the materials used in these facilities contained lead, and with the discovery of lead’s toxicity in the late 20th century, it was claimed to be the dominant cause of Rome’s collapse. Since one in five Roman citizens lived in the city, it is certainly plausible that lead accumulated in their bodies.

Lead is indeed harmful to living organisms. But the simple linear equation that Rome fell solely due to lead poisoning is problematic. Rather, I think it is appropriate to consider how to fit this factor into the complex story of the collapse of a great civilization.

Stories are an important element for humanity. We created stories and believed in them, which led to the civilization we have today. However, belief can also make humans psychologically vulnerable. Because of this belief, confirmation bias and the Barnum effect occur regarding certain events. People tend to see only what they want to see or accept information that aligns with their beliefs, and even general stories are often perceived as their own. Therefore, it is not easy to find the truth on internet platforms overflowing with fake news and strong claims based on unclear evidence.

Urban engineering systems such as water supply and sewage
Lead included in facility materials
Claimed to accumulate in citizens’ bodies causing collapse
One of over 200 existing hypotheses

First, let’s clarify the story about lead in Rome. The connection between lead and the fall of the Roman Empire began in 1965 with American historian Gill Fillon’s study on Roman lead exposure. He pointed out that lead was used not only in the water system but also in most daily items such as tableware, coins, and cosmetics. However, since metal salts do not easily leach, the most significant factor was that Romans preferred wine over water, which contained more lime. The over-fermented acetic acid in wine reacts with lead to form lead acetate (Pb(CH3COO)2). Lead acetate, also called “sugar of lead,” tastes sweet. Romans drank wine instead of water, and it also served as a sweetener. Various symptoms of lead poisoning could cause antisocial behavior in decision-makers, thus influencing the rise and fall of civilizations. Still, it is insufficient to claim it as the dominant cause of collapse. Here, another question arises: wine is not a popular beverage even today. There must have been many alternative foods, so why did they choose expensive wine?

Recent historians say that Romans were under extreme stress and chose wine to relieve it. Modern people rely on various indulgences like sugar and alcohol to relieve stress. But it was different back then. Sugarcane was cultivated in Persia only in the 5th century, and tobacco came to Europe from the New World during Columbus’s Age of Exploration, so wine was probably the best option at the time. Then another question arises: what was the main source of their stress that led them to consume so much wine?

In fact, the fall of Rome was not caused by one or two factors. There are over 200 existing hypotheses. The main cause was the inherent limitations of the imperial system, with population growth, decadent culture among the ruling class, and tyranny adding flesh to the bones. The infamous Nero, a corrupt ruler and symbol of the Antichrist, is well known for his tyranny, including burning Rome while reciting poetry. There were many abnormal figures like Emperor Caligula, who claimed equality with the sky god and fed slaves to beasts used in gladiatorial games. The final blow was external invasions that constantly shook the unstable core of Rome. These are well-known historical facts.

System limitations + population growth + tyranny
Mild climate and new infectious diseases also contributed
Wine’s acetic acid combined with lead creates sweetness
Consumed to relieve stress, leading to lead poisoning
Biological disasters succumbed to nature’s power

However, most stories about Rome’s fall overlook the natural environmental background. Stories tend to focus on people and events, so the environment is often missed. The name Mediterranean evokes a mild and stable climate. In fact, during Rome’s heyday, the climate was much milder than today’s Mediterranean climate. Crops sensitive to frost, like olives and grapes, were harvested more abundantly. Wine could have been a popular drink more than we think. Evidence such as ancient olive cultivation facilities located above today’s cultivation limits supports this. Various artifacts from the past indicate that after the 2nd century, Rome’s natural environment underwent significant changes. Scientific evidence from glaciers, tree rings, and long strands of nucleic acids shows that climate change and new infectious diseases appeared several times, disrupting social balance and causing extreme stress to Romans. Moreover, their proud urbanization and development actually facilitated the spread of epidemics.

Ancient people created gods and symbols to understand the origin and behavior of the world. Myths go beyond fiction, providing humanity with wisdom by learning lessons from symbolic figures or events and applying them to life. Ancient people worshipped and feared the goddess Fortuna, the goddess of fate. Just as the word “fortune” derives from her name, Rome worshipped all her blessings until the mid-2nd century, the empire’s peak. But since she was a goddess of fate who could overturn human life, she was also feared. The object of fear was not brutal military rule or war but the immense power of nature.

The fall of Rome was the result of a mixture of social structural problems, physical climate change, and biological disasters?nature’s power. Today’s climate change is caused by humans releasing pollutants into the atmosphere, while back then it was the opposite, a Little Ice Age. Yet, both then and now, humanity is enduring nature’s experiments with fluctuating temperatures. Romans likely suffered more than we do and struggled desperately to maintain and restore prosperity and order. But as hundreds of causes landed one after another, the weakened civilization collapsed helplessly. Science now allows us to insert environmental backgrounds like climate and disease into the grand story of Rome’s fall. Interpreting Rome’s fall solely as human history left no clear, penetrating thread. Now we can see how absurd the claim that lead poisoning alone caused Rome’s fall really is. Of course, finding causes is important, but how we weave those elements into the story is even more crucial.

The fall of Rome is a story of nature conducting physical and ecological experiments on human society. Even humanity, which achieved unprecedented civilization, is vulnerable as nature finds and exploits the weakest points to create cracks. I am sure I am not the only one who finds this story strikingly similar to today’s situation. Do we have lessons from the current climate change and pandemic? We should not see them merely as news events. It is not just about lamenting heatwaves and floods or counting daily infection numbers. We must symbolize physical and ecological changes within a grand narrative. Only then can we gain lessons and write future stories. Despite the Intergovernmental Panel on Climate Change (IPCC) presenting scientific evidence in its recent 6th Assessment Report that the climate crisis is progressing faster and more severely than expected, it has not become a major issue and quietly faded away. People probably do not believe this cruel fairy tale. Or perhaps they do not want to believe it.

But perhaps we have never had a proper chance to hear this cruel fairy tale. Just as we trusted the grandmother who told us wolf stories when we were young, the messenger’s role is as important as the message in delivering stories and lessons. So, who are you listening to for stories about the world?

By Byeongmin Kim, Adjunct Professor, Nano Convergence School, Hallym University

This content was produced with the assistance of AI translation services.