Will it be winter in the northern hemisphere in july in about 13,000 years due to the precession of the rotation axis of the earth and does this also imply that in a few thousand years (6000) there will not be any seasons at all?
The equinoxes are moving with time because of the precession
of the poles, and winter would indeed be in July in
approximately 13,000 years for the northern hemisphere.
However, there will be seasons, just as now, in 6,000 years.
The only thing that will be different is the direction that
the North pole will point (90 degrees from where it points now)at the same position of the Earth in it's orbit about the Sun, and the seasons will be shifted 3 months from what they are now.
The only condition in which there would essentially be no seasons would be if the North-South pole axis were perpendicular to the plane of it's orbit around the Sun. There would be only minor
differences in temperature, etc. resulting from the ellipticity
of the Earth's orbit.
In 13,000 years,instead of the North pole pointing away
from the Sun on Dec. 22, it will be pointing toward the Sun.
So, one thing that could be different is the intensity of winter
and summer in the Northern hemisphere in 13,000 years.
Presently the Earth is closest to the Sun during Northern
hemisphere winter and farthest away during summer. In 13,000
years the Earth will be closest to the Sun for Northern
hemisphere summer and farthest away for winter, perhaps
making winters colder and summers hotter.
Argonne National Laboratory
Click here to return to the Environmental and Earth Science Archives
Update: June 2012