Human history stretches so far back in time, it’s almost incomprehensible. Just over 70,000 years ago, humanity was reduced to a small group of about one thousand reproductive adults who survived a natural disaster that nearly wiped out our species. 

Some scientists believe all modern humans share DNA with this group. Others argue that, like the dinosaurs, we almost went extinct. We were evolving as a species, foraging for food, forming communities, and populating the planet, until Mount Toba fractured the timeline. 

Let’s travel back to the Old Stone Age, or Paleolithic period, when human life was threatened to the brink of extinction.

MOUNT TOBA

Homo sapiens living in 70,000 B.C. were hunters and gatherers, constantly adapting to changing ice-age climates. Little did they know, their environment was about to be overhauled for the foreseeable future and beyond. 

During the Middle Paleolithic period, archaic humans, “Neanderthals,” were fostering connections, refining their diets, reproducing, and inventing tools to navigate their corners of the world.

Then, Mount Toba (located in modern-day Sumatra, Indonesia) erupted, spewing “650 miles of vaporized rock into the air” according to NPR’s Robert Krulwich. To put this into perspective, Mount Vesuvius (Pompeii) ejected three cubic kilometers of material, Mount Tambora (the “Year Without a Summer”) 80, and Mount Toba, 2,800. The eruption was so immense that ash from this disaster remains visible in geological records today.

As if the climate wasn’t already unruly, humans now peered up at a sun “dimmed” for an estimated six years by ash, causing extensive global cooling and the destruction of resources. Some perished immediately, while entire communities on other continents starved to death. Earth experienced a staggering five to nine-degree drop in temperature, with effects that lingered for thousands of years.

Estimates on the population decrease vary. Some experts suggest humanity was reduced to 1,000 reproductively active individuals; others believe it was even fewer. The survivors reproduced slowly, as harsh conditions and food scarcity continued.

According to the BBC, the aftermath of the eruption eventually forced people to band together in larger groups for survival, and these communities, in turn, thrived.

THE YOUNGER DRYAS

The Toba eruption wasn’t the last climate event to threaten human existence. Roughly 14,500 years ago, NOAA reports, the Northern Hemisphere underwent abrupt cooling before warming extensively (allowing us to transition into the current epoch).

This drastic change, referred to as “The Younger Dryas,” again caused a significant dip in the human population, and it took over two thousand years for our species to recover.

THE HOLOCENE EPOCH

Eventually, we entered the Holocene Epoch and the New Stone Age, when Neolithic humans experienced a population boom and established agricultural settlements. Stable climates and abundant food allowed communities to grow, prompting the need for skilled labor that ultimately laid the groundwork for modern society.

By 200 BC, the world’s population had exceeded one million; by 1804, it reached one billion. In 2026, there are over 8.3 billion people on Earth. That’s about 56 people per square kilometer. While our technology to predict catastrophic events is better than ever, we are not immune to calamity. If Mount Toba and the Neanderthals have taught us anything, it’s that we remain at the mercy of the ever-unpredictable Mother Nature.

More Anthropology: