Quote:
|
Originally Posted by Volans
G'day Ian,
The Earth, as you know is tilted by 23.5deg. from the vertical. This angle can in fact change, anywhere between 21.5 and 24.5 deg. over a 41,000 year period. The main wobble in the Earth's rotation is called precession and this alters the direction of the Earth's tilt...not the angle of the tilt.
So you are correct in saying the angle of sunlight hitting the Earth effects climate but this angle will not change due to precession, so the climate will not change due to precession.
Peter.
|
Hi Peter.
While I agree that our climate as such will not change due to precession (I'll ignore other facts that are currently being debated in another thread), the timing of the seasons will change. If for example we look at the northern Autumnal Equinox, the Axial tilt of the earth is parallel to the direction of the earths orbit, with the north polar region leaning towards the direction of travel. This will lead in three months time to the northern Winter with the northern hemisphere leaning away from the sun.
Now in 6,500 years the earth will have progressed through one quarter of a full procession. Looking down from the north celestial pole the earth appear to precess in clockwise direction. This will mean that at the corresonding time of the year as we experience a northern Autumnal Equinox our future selves will experience a Northern Winter Solstice and our current Northern Winter will become a Spring Equinox