Previous Year Question

The Astronomical Theory of climate change, commonly associated with the Milankovitch Theory, is based on long-term cyclical changes in the geometry of the Earth-Sun system. Its three principal orbital factors are Eccentricity, Obliquity and Precession.

Eccentricity refers to changes in the shape of the Earth's orbit. Its major cycle is about 100,000 years. Obliquity refers to changes in the tilt of the Earth's rotational axis; it varies approximately between 22.1° and 24.5° and follows a cycle of about 41,000 years. Precession is the slow wobble in the direction of the Earth's rotational axis, with a cycle of approximately 26,000 years.

These three variations alter the distribution of solar energy received at different latitudes and during different seasons, thereby influencing long-term climatic patterns and glacial-interglacial cycles.

Solar irradiance refers to the amount of radiant energy received from the Sun. It can influence climate, but it is not one of the three orbital parameters of the Milankovitch Theory.