Final answer:
In about 13,000 years, the Earth's axial precession will align the Northern Hemisphere's summer with perihelion, resulting in an increase in summer radiation due to the more intense sunlight received from being closer to the Sun.
Step-by-step explanation:
The question addresses the subject of astronomy, specifically the seasonal radiation changes in the Northern Hemisphere due to the axial tilt of the Earth and its orbital position around the Sun. The Earth's axial tilt and precession affect the intensity and duration of sunlight received in different hemispheres throughout the year.
Presently, during the Northern Hemisphere's winter, the north pole points away from the Sun, and during the summer, around June 21, which we call the summer solstice, it points towards the Sun. However, in about 13,000 years, due to axial precession, the orientation will be such that the Northern Hemisphere's summer will coincide with when the Earth is closest to the Sun in its orbit, known as perihelion.
This shift will result in an increase in summer radiation for the Northern Hemisphere because being closer to the Sun at perihelion means receiving more intense sunlight. Conversely, the Southern Hemisphere will experience decreased summer radiation due to being farther from the Sun at aphelion (the point in the orbit where Earth is farthest from the Sun), thus emphasizing the notion that one hemisphere's gain in solar radiation is the other hemisphere's loss.