Final answer:
Milankovitch cycles are long-term changes in Earth's orbit that influence climate by affecting solar radiation distribution. These include variations in eccentricity, obliquity, and precession, which occur over tens to hundreds of thousands of years, and are key to understanding natural climate variability.
Step-by-step explanation:
Milankovitch cycles are the result of cyclic changes in the Earth's orbit, which have a significant impact on Earth's climate over thousands to hundreds of thousands of years. These cycles are categorized into three main types: eccentricity, obliquity, and precession. Eccentricity concerns the shape of Earth's orbit around the Sun, transitioning from circular to elliptical over approximately 100,000 years and longer cycles of 400,000 years and 2.4 million years. Obliquity relates to changes in the angle of Earth's axis of rotation, with a cycle of about 41,000 years, and a longer cycle of 1.2 million years. Lastly, precession involves the wobble of Earth's rotational axis, with a period of roughly 26,000 years.
These Milankovitch cycles affect the way solar radiation is distributed on Earth, influencing global temperatures and potentially leading to climate events such as ice ages. The work of Milutin Milankovitch in the 1930s, which linked these orbital patterns to past ice ages, remains a significant theory in understanding natural climate variability. Nevertheless, the cycles are gradual and cannot account for the rapid and pronounced increases in global temperature and carbon dioxide concentrations observed in recent decades.