Researchers have previously hypothesized that an environmental trigger may have helped set in motion the crop failures, famines and social unrest that plagued the Mediterranean region at the time when the Roman Republic collapsed.
What environmental trigger could have been so powerful? An excellent article by Katherine Kornei in The New York Times (22 Jun 2020) provides the explanation.
Here are excerpts (along with some paraphrasing) from that article:
Chaos and conflict roiled the Mediterranean in the first century B.C. Against a backdrop of famine, disease and the assassinations of Julius Caesar and other political leaders, the Roman Republic collapsed, and the Roman Empire rose in its place.
Scientists on Monday announced evidence that a volcanic eruption in the remote Aleutian Islands – Mount Okmok – contributed to the Roman Republic’s demise. That eruption — and others before it and since — played a role in changing the course of history.
Joseph McConnell, a climate scientist at the the Desert Research Institute in Reno, Nevada, and his collaborators recently analyzed six ice cores drilled in the Arctic. In layers of ice corresponding to the early months of 43 B.C., they spotted large upticks in sulfur and, crucially, bits of material that were probably tephra. The timing caught the scientists’ attention.
This eruption was one of the largest of the last few millenniums, Dr. McConnell and his collaborators concluded, and the sulfate aerosols it created remained in the stratosphere for several years. These tiny particles are particularly good at reflecting sunlight, which means they can temporarily alter Earth’s climate.
There’s good evidence that the Northern Hemisphere was colder than normal around 43 B.C. Trees across Europe grew more slowly that year, and a pine forest in North America experienced an unusually early autumn freeze. Using climate models to simulate the impact of an Okmok eruption, Dr. McConnell and his collaborators estimated that parts of the Mediterranean, roughly 6,000 miles away, would have cooled by as much as 13.3 degrees Fahrenheit.
“It was bloody cold,” Dr. McConnell said.
Rain patterns changed as well — some regions would have been drenched by 400 percent more precipitation than normal, the modeling revealed.
These cold, wet conditions would have almost certainly decimated crops, Dr. McConnell and his colleagues said. Historical records compiled by Roman writers and philosophers note food shortages and famines. In 43 B.C., Mark Antony, the Roman military leader, and his army had to subsist on wild fruit, roots, bark and “animals never tasted before,” the philosopher Plutarch wrote.
“It’s an incredible coincidence that it happened exactly in the waning years of the Roman Republic when things were falling apart,” said Dr. McConnell, who published the team’s results in Proceedings of the National Academy of Sciences.
Read all of this great article: