The Next Ice Age Quiz: Exploring Earth's Frozen Future

Dinosaurs were not present during the last Ice Age; they had become extinct approximately 65 million years ago at the end of the Cretaceous Period. The last Ice Age, part of the Pleistocene Epoch, featured a range of large mammals like woolly mammoths, saber-toothed tigers, and mastodons. Dinosaurs had long since disappeared from the Earth's ecosystem by the time these Ice Age creatures roamed.

Many Ice Age animals had adaptations such as thick fur to insulate them against the cold climates. Species like the woolly mammoth and the woolly rhinoceros are notable for their extensive body hair, which provided necessary protection from the frigid temperatures and harsh environmental conditions prevalent during glaciation periods.

The last Ice Age occurred during the Pleistocene Epoch, which lasted from about 2.6 million to 11,700 years ago. This period is characterized by repeated glacial cycles where ice sheets and glaciers expanded across continents. The Pleistocene follows the Pliocene Epoch and precedes the current geological epoch, the Holocene, marking it as a significant time of climatic change and evolutionary development for many species, including humans.

Ice Ages begin primarily due to changes in the Earth's orbit, which affect the amount of solar energy our planet receives. This process is part of what's known as Milankovitch cycles, which include changes in the tilt of Earth's axis and the shape of its orbit around the sun. These cycles lead to significant variations in climate over tens of thousands to hundreds of thousands of years, gradually causing glaciers to expand and the onset of an ice age.

During the Ice Age, humans relied heavily on spears for hunting and survival. Spears were versatile tools that could be used for both close-range and long-range hunting, making them effective for a variety of prey. The design of spears also evolved over time, with advancements in materials and construction techniques leading to more efficient and deadly weapons. While other tools like axes, bows, and atlatls were also used during the Ice Age, spears were the most prevalent and essential tool for human survival.

Ice ages cause significant decreases in sea levels, primarily because vast amounts of water are locked up in ice sheets and glaciers. During peak glacial periods, sea levels were much lower than they are today, exposing areas that are now underwater and creating land bridges such as the one between Asia and North America, which facilitated migrations of animals and humans.

The Bering Land Bridge, or Beringia, was exposed due to lower sea levels caused by the glaciation during the Ice Age. This land bridge connected what are now Russia and Alaska, allowing for the migration of people and animals between North America and Asia. It played a crucial role in the prehistoric colonization of the Americas by humans.

The scientific term for an Ice Age is a "glacial period," which refers to times in Earth's history when polar and mountain ice sheets were unusually extensive across the planet's surface. Several glacial periods have occurred throughout Earth's history, not just during the Pleistocene but also at other times when conditions led to long-term reductions in global temperatures.

After an Ice Age, levels of carbon dioxide in the atmosphere generally increase. This is due to several factors, including the release of CO2 from the ocean as it warms. During ice ages, cooler global temperatures allow oceans to absorb more carbon dioxide. When temperatures rise as glaciers melt, this CO2 is released back into the atmosphere, contributing to a natural increase in greenhouse gases.

Milankovitch cycles are the theory that explains the occurrence of ice ages. These cycles involve changes in Earth's orbital shape, axial tilt, and precession (a change in the orientation of the rotational axis). These changes affect the amount and distribution of solar energy received by Earth, which in turn influences long-term climate patterns such as glaciation and interglacial periods.