Which of the following was NOT considered by Milankovitch in his mathematical model of climate change?

Question

Which of the following was NOT considered by Milankovitch in his mathematical model of climate change?

1. A. Change in the angle of inclination of the earth
2. B. Change in the eccentricity of the earth's orbit
3. C. Precession of equinoxes (Correct answer)
4. D. Changes in the rate of rotation of earth on its axis

Correct Answer

Option C — Precession of equinoxes

Detailed Solution & Explanation

The correct answer is Precession of equinoxes.

Key Points

• The official answer key identifies precession of equinoxes as the factor not considered by Milankovitch in his model.
• The primary Milankovitch cycles are eccentricity, axial tilt (obliquity), and precession — though different interpretations of the model exist.

Additional Information

• The three cycles Milankovitch actually modelled are eccentricity (~100,000 years), axial tilt or obliquity (~41,000 years) and precession (~26,000 years); together they govern the timing of glacial cycles.
• Note that precession *is* generally counted among the Milankovitch cycles, so this item has been contested. Follow the official key for this paper, but be aware of the standard three-cycle formulation.
• The theory explains the timing of ice ages, not their full magnitude, which requires feedbacks such as albedo and carbon-dioxide changes.