第四纪时期万年尺度的气候振荡是由地球轨道要素（偏心率、地轴倾斜、岁差，简称EPT）变化所导致．然而，最近几年在极地冰岩芯及北大西洋深海沉积中发现了一序列轨道尺度以下的气候振荡，这些百年或千年尺度的气候回动显然不能用米兰柯维奇的地球轨道理论加以解释，也由此传统的第四纪古气候理论面临新的挑战． The Quaternary period-scale climate oscillations are caused by changes in the Earth’s orbital elements (eccentricity, axial inclination, precession, or EPT). However, in recent years, a series of climatic oscillations below the orbital scale have been found in polar ice cores and deep-sea sediments of the North Atlantic. The climatic fluctuations at these centennials or millenium scales are obviously not explained by the Milankovitch orbit theory, This traditional Quaternary paleoclimate theory is facing new challenges.