Kliimatsüklid

Kliimatsüklid refer to long-term variations in Earth's climate. These cycles are driven by a combination of natural factors, primarily changes in Earth's orbit around the Sun, known as Milankovitch cycles. These orbital variations affect the amount and distribution of solar radiation reaching Earth's surface.

The most significant of these cycles are the eccentricity of Earth's orbit (the shape of the orbit changes from nearly circular to more elliptical), the obliquity of Earth's axial tilt (the angle of Earth's tilt varies), and the precession of the equinoxes (the wobble of Earth's axis). These shifts, occurring over tens of thousands to hundreds of thousands of years, influence the intensity and seasonality of sunlight.

These orbital changes can trigger feedback mechanisms within the Earth system, such as alterations in ice sheet extent, ocean currents, and atmospheric composition, which in turn amplify or dampen the initial climate variations. For example, during periods of increased solar radiation in the Northern Hemisphere summer, ice sheets are more likely to melt, leading to a lower albedo (reflectivity) and further warming.

Historically, these natural cliimatsüklid have been responsible for glacial and interglacial periods, where large ice sheets covered vast areas of the planet followed by warmer intervals. While human activities are currently causing rapid climate change, understanding these natural cliimatsüklid provides essential context for comprehending Earth's long-term climate variability.