Many different causes likely contributed to the fall of the Roman Empire, in the various stages of that phenomenon. But new research has identified a significant factor that may have pushed things past the final tipping point, sealing the Empire’s fate and guaranteeing its status as historical memory.
Fresh geological findings from Iceland suggest that a dramatic cooling event known as the Late Antique Little Ice Age (LALIA), associated with a notable global temperature drop, likely played a much larger role in the fall of the Roman Empire than previously understood.
For years, scholars have speculated that shifts in Earth's climate may have weakened the once-mighty Roman Empire, leaving it vulnerable to external threats, economic trouble, and internal conflict. Now, research led by scientists from the University of Southampton and Queen's University has added weight to this theory, linking a sudden climate downturn to the empire's ultimate demise in 1453 AD. It was in this year that the Ottoman Empire conquered Constantinople, the capital of the Byzantine or Eastern Roman Empire, officially bringing the long Roman era to an end.
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Evidence uncovered from a remote stretch of Iceland's coastline suggests that the LALIA, a period of intense cooling triggered by volcanic eruptions, was “more severe than previously thought.” Dr. Thomas Gernon, a professor of Earth Sciences at the University of Southampton and co-author of the study, told the DailyMail.com that this cold spell had far-reaching consequences.
“When it comes to the fall of the Roman Empire, this climate shift may have been the straw that broke the camel’s back,” Gernon stated.
The team’s research has just been published in the journal Geology.
A True Global Catastrophe
The Roman Empire had split in two by 286 AD, dividing into Western and Eastern realms. The Western portion crumbled first, succumbing to foreign conquest around 476 AD. But the Eastern Roman Empire—often referred to as the Byzantine Empire—endured for almost another thousand years. It was during this time that the Little Ice Age developed, beginning around 540 AD and lasting between two and three centuries.
‘The Frozen Thames’ by Abraham Hondius, 1677, painting made during Little Ice Age. (Public Domain).
The climate shift was likely caused by a sequence of major volcanic eruptions. These events launched enormous volumes of ash into the atmosphere, forming a hazy veil that blocked sunlight and cooled temperatures across much of the planet.
While a 1.8 to 3.6°F drop may seem minor by modern standards, the impact on the ancient world was profound.
“It was enough to cause widespread crop failures, increased livestock mortality, a sharp rise in food prices, and ultimately, widespread illness and famine across the Empire,” Gernon noted.
This frigid period also overlapped with another catastrophe: the Justinian Plague, which first appeared in 541 AD. That pandemic swept through the empire and beyond, killing an estimated 30 to 50 million people. At the time, that accounted for nearly half of the global population, revealing the stunning impact of that outbreak.
“These events overlapped with a turbulent time in the Eastern Empire, which was engaged in near-constant warfare, territorial expansion under [Emperor] Justinian, and internal religious conflict,” Gernon said. All of these challenges, combined with the pressures of a collapsing climate, may have significantly impaired the empire’s ability to recover.
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Although the Eastern Empire technically endured long past the Little Ice Age, many historians believe the damage done during this icy period laid the groundwork for its eventual downfall. As Gernon put it, “It seems likely that the [LALIA] helped tip the balance at a moment when the Eastern Empire was stretched thin.”
Icelandic Rocks Reveal Sudden Climate Collapse
For the purposes of their study, the researchers collected important geological evidence along Iceland’s northwestern coast. There, within an elevated beach terrace, they found a collection of rocks that didn’t seem to belong.
Icelandic landscape: waterfalls of Gullfoss under the snow. (Pierre-Selim Huard/CC BY-SA 4.0).
“We knew these rocks seemed somewhat out of place because the rock types are unlike anything found in Iceland today, but we didn't know where they came from,” said Dr. Christopher Spencer, lead author of the study and associate professor at Queen’s University.
To trace the origins of these mysterious stones, the team crushed them into fragments and analyzed tiny zircon crystals embedded within. These minerals are particularly valuable in geological research because they retain chemical and chronological information about their formation.
“Zircons are essentially time capsules that preserve vital information including when they crystallized as well as their compositional characteristics,” Spencer explained. “The combination of age and chemical composition allows us to fingerprint currently exposed regions of the Earth's surface, much like is done in forensics.”
What they found was surprising: the rocks likely came from Greenland and were carried across the ocean by icebergs that drifted southward during the LALIA. “This is the first direct evidence of icebergs carrying large Greenlandic cobbles to Iceland,” Spencer noted.
That discovery was important for two reasons. First, it shows the Greenland Ice Sheet must have been advancing and retreating more dramatically than usual. Second, the climate during this period must have been cold enough for icebergs to drift farther south than normal—cold enough, in fact, to alter Iceland’s geological makeup.
Frozen into Oblivion
This new evidence supports the idea that the Little Ice Age was a major climatic episode that caused significant environmental upheaval on a global scale. The Roman Empire, already under stress, was likely pushed further into decline by the harsh conditions brought on by volcanic winters and cooling seas, gradually succumbing to natural forces they didn’t understand.
“To be absolutely clear, the Roman Empire was already in decline when the [LALIA] began,” Gernon emphasized. “However, our findings support the idea that climate change in the northern hemisphere was more severe than previously thought. Indeed, it was probably a major driver of major societal change, rather than just one of several contributing factors.”
‘The Hunters in the Snow" by Pieter Bruegel the Elder. 1565, based on his trip across the Alps on his way to visit Rome. (Public Domain).
As researchers continue to investigate how natural forces have shaped human civilization, the story of the Late Antique Little Ice Age’s impact reveals the vulnerability of even the most enduring culture to game-changing alterations in climate. As resilient as it was, the Eastern Roman Empire simply had no answers for the slow-moving emergency they faced.
Top image: Theophilos Hatzimihail, ''The Siege of Constantinople'', from 1932, depicting Ottoman capture of the Eastern Roman Empire capital.
Source: Public Domain.
By Nathan Falde
