在这种情况下，地球在一年中所经历的总日晒量应该与日冕进动的程度无关——实际上，从黄道面上观察太阳-地球系统的观测者不应该能够区分日冕的5度进动和观测者在相反方向上的5度旋转。既然后者不能影响地球的气候，我们也不应指望前者会。< / p >
Clearly, I'm making some sort of mistake here, but I'm not sure where exactly my thinking has gone wrong. Where is my error?
The solution to this apparent paradox and the answer your question (how does apsidal precession alone affect the climate) are one and the same: The uneven distribution of land and water between the northern and southern hemispheres. The northern hemisphere has about twice as much land as does the southern hemisphere. Continental climates exhibit much more seasonal variability than do maritime climates.
That worldwide insolation is greatest in January and least in July is a bit irrelevant. What is more relevant is the length of the seasons in the northern hemisphere. Right now, summer is longer than is winter in the northern hemisphere because perihelion is in early January. This situation will be reversed in ten thousand years when perihelion and northern hemisphere summer solstice coincide. Looking at precession only, glaciation is much more likely during periods where northern hemisphere summers are short and winters are long.
岁差对气候的影响主要由两个因素引起:
(1)轴向岁差
(2) Apsidal岁差
apses的岁差本身并不引起气候状态的变化。然而，这种运动与轴向进动(地轴的陀螺仪运动)具有相同的意义。这种效应使进动周期从26kyr缩短到21kyr。< / p >
Combined, the two effects cause what is known as the precession of the equinoxes. If you consider this a cyclic process, the two extreme precessional configurations are shown below: 
See NH++. In this configuration, NH summer is at perihelion. Thus, during NH summer, earth is closest to the sun, and therefore Northern hemisphere has a strong summer. During NH winter, earth is farthest from the sun, therefore Northern Hemisphere has a weak winter as well. Thus in this precessional configuration, the earth has extreme seasons in the Northern Hemisphere.
Now see SH++. In this configuration, SH summer is at perihelion. Thus, during SH summer, earth is closest to the sun, and therefore the southern hemisphere has a strong summer. During SH winter, earth is farthest from the sun, therefore southern Hemisphere has a weak winter as well. Thus in this precessional configuration, the earth has extreme seasons in the southern Hemisphere.