10 Historical Events That Almost Killed Us All

Welcome to WatchMojo, and today we’re looking at scientific discoveries, experiments, and historical events that could have destroyed humanity.

Kola[a] Superdeep Borehole (1970-95)

In the 1970s, Soviet scientists embarked on a straightforward mission: to drill as deep into the Earth as possible. The Kola Superdeep Borehole, a 7.6-mile-deep chasm, remains the deepest artificial point on Earth. The experiments conducted there told us a great deal about both life on earth and the planet's makeup. But what if they’d gone deeper? Experts of the time worried about drilling into the Earth's mantle. Could such an experiment have triggered volcanic activity or seismic shifts? Luckily, the mantle remains unbreached. The project stalled in 1995 due to both skyrocketing temperatures and costs. Let’s just hope it wasn’t also a case of humanity dodging a geological bullet.

Nuclear War Games (1979)

In 1979, a training tape meant to simulate a Soviet nuclear attack was accidentally fed into NORAD[b]'s live warning system. The resultant scare nearly led to nuclear Armageddon. Alarms blared as screens lit up with what appeared to be an incoming missile barrage. Military commanders scrambled to respond, alerting nuclear forces and bringing the world to the brink of catastrophe. Thankfully, cool heads noted that nothing was coming up on radar or seismic sensors. Fortunately, the error was caught before any retaliation orders were issued. Still, the incident exposed just how close humanity could come to accidental annihilation thanks to human error. It was a stark reminder that in the nuclear age, even a single man's accident could have deadly consequences.

Eruption of Mount Thera[c] (~1600 B.C.E.)

Volcanoes have shaped civilizations thanks to the fertile soils left in their fiery wake. But their destructive power also holds civilization-ending potential. Krakatoa’s 1883 eruption unleashed energy equivalent to 200 megatons of TNT, devastating Java and Sumatra. In 1815, Tambora’s eruption brought “the year without a summer. ” Ash in the atmosphere sent global temperatures plunging, sparking worldwide famines. But Mount Thera, which erupted around 1600 BCE, takes center stage in volcanic history. Its eruption obliterated much of the Minoan civilization, the real-life inspiration for Atlantis. The shock of the explosion sent tsunamis cascading through the Mediterranean Sea, devastating many early human settlements. Had the aftereffects been more widespread, humanity might have been set back centuries - or worse.

“The Carrington[d] Event” (1859)

In 1859, the sun unleashed a geomagnetic storm so powerful it electrified telegraph lines, sparked fires, and created auroras visible near the equator. Known as the Carrington Event, it was a cosmic warning shot to the future of electronic-age humanity. At the time, the world ran on steam, coal, and oil. Electricity was both rare and simple, with the effects of the solar storm localized and minimal. Today, our interconnected digital infrastructure is far more vulnerable. A modern equivalent could fry satellites, disable power grids, and plunge modern society into utter chaos. Estimates suggest such an event would cost trillions in damage. It would take a modern society years to recover from a repeat of the Carrington Event.

Cuban Missile Crisis (1962)

The Cuban Missile Crisis brought humanity to the very brink of nuclear annihilation. As the United States discovered Soviet missile installations in Cuba, tensions escalated into a 13-day standoff. Behind the scenes, military leaders on both sides advocated for war. U.S. generals proposed an invasion of Cuba. Soviet commanders in Cuba were authorized to launch tactical nuclear strikes if attacked. President John F. Kennedy and Soviet Premier Nikita Khrushchev [e]ultimately chose diplomacy over devastation. They negotiated a secret deal that removed missiles from both Cuba and, eventually, Turkey. The crisis was a stark reminder of how human decision-making narrowly averted catastrophe. Had cooler heads not prevailed, civilization as we know it could have ended in nuclear fire.

The Chicxulub[f] Impact (66,000,000 B.C.E.)

Near misses with asteroids remind us how precarious life on Earth can be. In 1989, the asteroid 4581 Asclepius skimmed past our planet at a cosmic hair’s breadth. Now imagine an asteroid not missing - like the Chicxulub impact. A space rock the size of Mount Everest slammed into what is now Mexico’s Yucatán Peninsula more than 66 million years ago. The collision released a level of energy that is difficult to comprehend. Firestorms and acid rain ensued. The impact also triggered a “nuclear winter” that blocked sunlight. This instant ice age collapsed most ecosystems, wiping out 75% of life on Earth, including most dinosaurs. A similar impact in the future would almost certainly deliver equally deadly results.

Spanish Flu (1918-20)

In an increasingly globalized world, pandemics reveal the vulnerable underbelly of human civilization. COVID-19 paralyzed the planet, killing millions and exposing the fragility of our interconnected systems. But even this pales in comparison to the Spanish flu of 1918. Emerging in the shadow of World War I, the influenza virus infected one-third of the global population. The death toll of the Spanish Flu was estimated by many as 50 million people. This far eclipsed the death toll of the war itself. With no antibiotics to treat secondary infections and limited medical knowledge, it spread with terrifying speed. It devastated urban centers and remote villages alike. Infrastructure crumbled, economies stalled, and communities were pushed to the brink. A deadlier communicable virus could ostensibly destroy humanity outright.

Ice Age (194,000 -135,000 BCE) & The Toba[g] Supervolcano (70,000 B.C.E.)

During the devastating glacial periods, humanity teetered on the brink of extinction. As ice sheets expanded across vast swaths of the planet, the climate grew colder and drier. In this era before agriculture, food sources were decimated. Early humans were left with a choice: migrate or perish. Many did both. Through the millennia and centuries, Homo sapiens struggled to survive. The eruption of Toba the supervolcano further affected global temperatures around 70,000 years ago. Genetic evidence suggests that Homo sapiens dwindled to as few as 1,000 individuals. The "population bottleneck" was so severe it could have ended our species entirely. Survival demanded ingenuity, as small bands clung to life near Africa’s coasts, relying on marine resources for sustenance.

The Black Plague (1346-1353)

The Black Plague was one of the deadliest diseases in human history, killing an estimated 50 million people worldwide. It destroyed nearly 1/2 of Europe's population alone. The disease tore through towns and cities with terrifying speed. It spread along trade routes, leaving devastation in its wake. Societies crumbled as fear and superstition gripped survivors. Labor shortages reshaped both the economy and social hierarchies. But the plague wasn’t just a natural disaster; it was also an early example of biological warfare. In 1347, Mongols besieging the city of Caffa[h] allegedly launched plague-ridden corpses over the walls, likely accelerating its spread into Europe. This dark precedent highlights the risks of weaponized diseases today, as advancements in biotechnology make pathogens like plague or smallpox potential weapons.

Trinity Test (1945)

The Trinity Test marked the birth of the nuclear age. It was an age born in fire with the potential to end just as quickly. As the first-ever detonation of a nuclear device, it was an experiment shrouded in uncertainty. Some Trinity scientists even feared that the explosion would ignite the Earth’s atmosphere. Such a chain reaction could consume the planet in fire. While those fears proved unfounded, the test confirmed humanity’s ability to unleash catastrophic destruction. Since then, nuclear weapons have brought us perilously close to annihilation. Near-misses, from misinterpreted radar signals to mistaken drills, remind us how easily things could spiral out of control. The haunting specter of the Trinity Test’s hypothetical conflagration mirrors the real, ongoing threat of nuclear war.

Both the earth and humanity have faced a heap of close calls and near misses. Are there any missing from our list? Let us know in the comments below.

[a]Kola = cola

[b]NORE-ad https://www.dictionary.com/browse/NORAD
[c]THEE-ruh https://www.dictionary.com/browse/thera
TAWMBO-ruh https://www.dictionary.com/browse/tambora
[d]care-ing-tin https://youtu.be/2Iwpyvou1f4?si=J7IVaRSgU0pOyzBt&t=7
[e]nik-KEE-tah KROOSE-chev https://forvo.com/search/Nikita%20Sergeyevich%20Khrushchev/
[f]chick-shoo-LOOB https://forvo.com/search/Chicxulub/en/
[g]TOH-buh https://youtu.be/AWUTlVxOsIw?si=qWC2oUYzFl7qE3cH&t=9
[h]CAF-uh https://youtu.be/XOcbb1Dvotw?si=1Vp5K4oncA0QMtST&t=64