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The Ice Age has always puzzled scientists. It’s known that these periods can blanket entire continents with vast frozen landscapes. We’re aware that there have been about 11 such events, and they occur at relatively regular intervals. One thing’s for sure: they were marked by an overwhelming amount of ice. However, there’s still much more to learn about these frosty epochs.
10. Mammoth Creatures
When the final Ice Age came about, evolution had already shaped mammals. The creatures that managed to endure the freezing conditions were typically large and covered in thick fur. Scientists label them 'Megafauna,' and these beasts survived the harsh climate due to their evolution in similarly frigid areas like Tibet. Ice ages effectively became their domain, as many other species couldn’t withstand the cold and faded away.
Megafauna herbivores had adapted to the icy environment, finding food in various clever ways. For example, an Ice Age rhinoceros might have had a shovel-like horn to clear snow. Carnivores such as saber-toothed cats, short-faced bears, and dire wolves (yes, those massive Game of Thrones wolves are based on real historical creatures) also had a relatively easy time. Although their prey fought back, it was large, meaty, and plentiful.
9. Ice Age Humans
Even though Homo sapiens weren't particularly large or furry, they survived the icy tundras of the Ice Age for thousands of years. Life was tough and cold, but humans were resourceful. About 15,000 years ago, Ice Age humans lived in hunter-gatherer tribes, created shelters from mammoth bones, and stitched clothing from animal hides. When game was abundant, they stored food in permafrost, which acted like a natural freezer.
Given that their hunting tools were mostly stone knives and arrowheads, advanced weaponry was scarce. To hunt large Ice Age creatures, people relied on traps. Once the animal triggered the trap, groups of men would attack and overpower it together.
8. Mini Ice Ages
Occasionally, smaller ice ages appear between the major, full-scale ones. While they aren’t as catastrophic, they can still lead to famine and disease, primarily from failed crops and other harmful consequences.
The most recent of these smaller ice ages began sometime between the 12th and 14th centuries, peaking from 1500 to 1850. For centuries, the Northern Hemisphere experienced unusually cold weather. In Europe, seas would regularly freeze, and in cold, mountainous regions like Switzerland, glaciers relentlessly advanced, crushing entire villages. There were years without summer, and the harsh conditions influenced every aspect of life and culture, possibly explaining why the Middle Ages are often viewed as a particularly dark time in history.
Scientists are still working to understand the causes of this mini Ice Age. It is believed that a combination of intense volcanic activity and a temporary decrease in the Sun’s solar output might have played a role.
7. A Mild Ice Age
Some ice ages may have actually been relatively warm. While the ground was covered in immense layers of ice, the actual weather could have been quite mild.
In some cases, the factors triggering an ice age were so extreme that even with a sky full of greenhouse gases (which trap the sun’s heat and warm the planet), ice still began to form. Once the pollution in the atmosphere reached a certain density, it could reflect the Sun’s rays back into space. Experts believe this could have created a “Baked Alaska” effect—cold on the inside (with ice covering the surface), but warm on the outside (due to a heated atmosphere).
6. Louis Agassiz
Ah, Louis Agassiz. A name that might sound more suited to a tennis player, yet this man was a distinguished scientist, one of the intellectual giants of the 19th century. He is celebrated as one of the founding fathers of American science, despite being originally from France.
Among his numerous achievements, Agassiz is essentially the reason we have any knowledge about ice ages. Though the idea had been considered before, it was Agassiz who, in 1837, first seriously proposed the existence of a past ice age. His theories and publications about vast ice fields that once spanned much of the earth were initially laughed off as nonsense. But he persisted, and with further research and geological evidence, his once-ridiculed theory eventually gained acceptance.
Interestingly, Agassiz’s groundbreaking work on ice ages and glaciers was more of a passion project. His true profession was ichthyology (the study of fish).
5. Human Pollution Might Delay the Next Ice Age
The idea that ice ages follow a predictable, recurring pattern regardless of human influence often clashes with the concept of global warming. While global warming is certainly real, some suggest that it could even help prevent future ice ages.
Carbon dioxide emissions caused by humans are a major contributor to global warming. However, they might have an unexpected consequence. Researchers at Cambridge University propose that human CO2 emissions could potentially stop the next ice age. Here’s how: Although Earth's natural cycles aim to trigger ice ages from time to time, they can only begin if carbon dioxide levels are unusually low. By releasing CO2, humans might have unintentionally made ice ages temporarily impossible.
Even if global warming—still a serious issue—causes humans to reduce CO2 emissions, we’ve already pumped so much CO2 into the atmosphere that even if we stopped entirely, the existing concentration could prevent an ice age for at least 1,000 years.
4. Ice Age Vegetation
Predators had it relatively easy during the ice ages—after all, they had a constant supply of prey. But what about the herbivores? What did they eat?
As it turns out, they had a wide range of options. Many plants were resilient enough to withstand the ice age conditions. Even the harshest ice ages still had steppes—vast areas of grassland and shrubland—that provided food for mammoths and other plant-eating animals. These grazing areas were teeming with plants that thrived in cold, dry climates, such as spruce and pine. In warmer regions, species like birch and willow were abundant. In general, the climate of these areas may have been quite similar to modern-day Siberia. The plants themselves were probably quite different from those we know today, though we still know very little about how individual plants adapted to the ice age environments.
That said, ice ages were not without their toll on plant life. If a plant species couldn’t adapt to the changing climate, its options were limited to migrating via seeds or facing extinction. For example, Victoria, Australia, once home to some of the most diverse plant life on Earth, saw much of that diversity wiped out by the ice age.
3. The Garden of Eden
Some researchers are strongly convinced that the Garden of Eden was real. They claim it was located in Africa and that it was the key reason our ancestors survived the ice age.
Around 200,000 years ago, a particularly harsh ice age was wiping out species across the globe. Fortunately, a small group of early humans managed to endure the severe cold. They found themselves along the coast of what is now South Africa. While much of the world was gripped by ice, this area remained free of it and entirely habitable. The soil was fertile and bountiful, with natural caves providing shelter. For a young species struggling for survival, it was essentially paradise.
The human population in this “Garden of Eden” is thought to have numbered only a few hundred individuals. This theory, supported by several experts but still lacking concrete evidence, aligns with research suggesting humans have notably less genetic diversity than most other species.
2. Snowball Earth
In most ice ages, glaciers cover only parts of the Earth. Even the most intense ice ages are said to freeze about one-third of the planet’s surface.
Then there’s Snowball Earth.
Snowball Earth is the ultimate ice age, the mother of all freezes. It’s a total freeze-out, where every inch of the Earth’s surface is coated in ice, turning the planet into a gigantic snowball hurtling through space. The only life that can survive such a brutal freeze either clings to the few places with minimal ice coverage or, in the case of plants, survives in areas where enough sunlight reaches for photosynthesis.
Evidence suggests that a complete Snowball Earth event occurred at least once, around 716 million years ago, and there may have been more.
1. Himalayas May Have Caused An Ice Age
Mountains are usually just known for standing tall, occasionally causing avalanches, but generally doing nothing more. However, the Himalayas challenge this stereotype. They might have actually been responsible for triggering an ice age.
Around 40-50 million years ago, when the landmasses of India and Asia collided, the force of the impact pushed up massive amounts of stone, creating the towering Himalayas. This exposed vast quantities of “fresh” rock to the atmosphere. Over time, this rock began to chemically erode, a process that gradually removed significant amounts of carbon dioxide from the air. This reduction in CO2 could have helped cool the Earth’s climate enough to initiate an ice age.
