Jääaigade

Jääaigade refers to ice ages, periods in Earth's history characterized by prolonged cold temperatures and the extensive presence of continental ice sheets, glaciers, and sea ice. These periods are typically defined by a significant drop in global temperatures and a subsequent increase in the Earth's ice cover. Ice ages are a recurring phenomenon in Earth's geological past, with distinct glacial and interglacial periods within each major ice age.

The most recent major ice age, often referred to as the Quaternary glaciation, began approximately 2.6 million years ago and continues to the present day, although we are currently in an interglacial period. During glacial periods of the Quaternary, vast ice sheets covered large portions of North America, Europe, and Asia, significantly altering landscapes through erosion and deposition. These ice sheets reached their maximum extent multiple times, with periods of advance and retreat.

The causes of ice ages are complex and are thought to involve a combination of factors. Key drivers include variations in Earth's orbit (Milankovitch cycles), changes in atmospheric composition, such as carbon dioxide levels, and geological events like continental drift and volcanic activity. The interplay of these factors influences the Earth's energy balance, leading to the formation and melting of ice sheets.

The effects of ice ages are profound and far-reaching. They have shaped coastlines, carved out valleys and fjords, and influenced the distribution of flora and fauna. The melting of ice sheets at the end of glacial periods has also led to significant sea-level rise. Understanding ice ages is crucial for comprehending Earth's climate history and for predicting future climate change.