Why Does the 100,000-Year Ice Age Cycle Dominate When Its Orbital Forcing Is Weak?
Milankovitch's own theory identifies the roughly 41,000-year obliquity cycle as the strongest orbital forcing on high-latitude summer sunlight, yet ice age cycles over the last million years have paced at roughly 100,000 years, matching the far weaker eccentricity cycle instead. This mismatch between the strength of the forcing and the size of the climate response is known as the 100,000-year problem.
What would resolve this A mechanism, such as an internal ice-sheet or carbon-cycle feedback, frequency modulation, or a stochastic-resonance effect, that amplifies the weak eccentricity signal into a full glacial cycle, confirmed against the detailed timing of the ice-core and ocean-sediment record.
PaleoclimatologyMilankovitch Cycles (Wikipedia)