jäätusaega

Jäätusaega, often translated as "ice age" or "glacial period," refers to a prolonged interval of time characterized by the presence of continental ice sheets and alpine glaciers. These periods are a natural part of Earth's long-term climate history, occurring over geological timescales. During a jäätusaega, significant portions of the planet's landmasses, particularly in the higher latitudes, become covered in vast sheets of ice. This glaciation dramatically impacts global sea levels, as water is locked up in the ice, leading to a lowering of sea levels. Conversely, when the ice sheets melt, sea levels rise.

The Earth has experienced numerous jäätusaega throughout its history, with the most recent one, the Quaternary glaciation, beginning around 2.6 million years ago and continuing to the present day, albeit with fluctuating warmer interglacial periods. These glacial and interglacial cycles are driven by a complex interplay of factors, including variations in Earth's orbit (Milankovitch cycles), changes in atmospheric composition (like greenhouse gas concentrations), and tectonic activity. The presence of ice sheets significantly influences erosion patterns, landforms, and the distribution of flora and fauna. Understanding jäätusaega is crucial for comprehending past climate changes and for predicting future climate scenarios.