The Earth's Precessional motion

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In summary, the Earth's precessional motion, which occurs every 26,000 years, causes a small perturbation in the Earth's tilt with respect to the sun. This can slightly affect the severity of seasons, but it is unlikely to have a lasting impact on global warming. The current angle of precession with respect to the sun is constantly changing, which can have a significant effect on the overall impact of precession.
  • #1
plutoisacomet
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Could the Earth's Precessional motion {40,000 years for one loop} cause or contribute to Global warming?
 
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See Milankovitch cycle (google)

The Earth's orbit around the sun is an ellipse, and the aphelion and perihelion shift over time and with respect to the solstices. In short, when summer occurs and the Earth is furthest away (aphelion), the northern hemisphere gets colder because there is less insolation. When summer occurs at perihelion the reverse is true, things heat up. That is the idea anyway.
 
  • #3
plutoisacomet said:
Could the Earth's Precessional motion {40,000 years for one loop} cause or contribute to Global warming?
Would you care to postulate a hypothesis as to how it might?

(Incidentally, IIRC it's more like 26,000 years)
 
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  • #4
Precession and Global Warming.

I'll bite.

The roughly 47.5 degrees of swing with respect to the equinoxes causes seasons. No big surprise there. The perturbation caused by precession of the poles is a tad under 0.7 degrees. So that would mean that the pole precession depending on the angle with respect to the sun would cycle between adding about 0.75% to the severity of seasons to lessening them by 0.75% and back over about 26,000 years.

With such a tiny addition or subtraction I don't see how it could have a lasting effect. We probably see more severe disturbances in weather due to sunspot activity, but that's just conjecture on my part.

So poster, here's a question, what is the current angle of precession with respect to the sun? Is the Earth tilted farther in towards the sun, out away from it, or is the current effect precession tending more to leading the Earth in orbit or following it? That would make a huge difference on even as small a number as you are looking at.
 
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1. What is the Earth's Precessional motion?

The Earth's Precessional motion is the gradual change in the orientation of the Earth's rotational axis over a period of approximately 26,000 years. This is caused by the combined effects of the Earth's axial tilt and its orbit around the sun.

2. What causes the Earth's Precessional motion?

The Earth's Precessional motion is primarily caused by the gravitational pull of the moon and sun on the Earth's equatorial bulge. This pull causes a slight wobble in the Earth's rotation, resulting in a change in the orientation of its axis.

3. How does the Earth's Precessional motion affect the seasons?

The Earth's Precessional motion does not directly affect the seasons. However, it does cause a gradual change in the position of the Earth's rotational axis relative to its orbit around the sun, which can have a minor impact on the length and intensity of the seasons over a long period of time.

4. How long does it take for the Earth's Precessional motion to complete one cycle?

The Earth's Precessional motion takes approximately 26,000 years to complete one cycle, known as a Great Year or Platonic Year. This is the time it takes for the Earth's axis to make a full circle and return to its original position.

5. What are the potential effects of the Earth's Precessional motion on Earth's climate?

The Earth's Precessional motion can have a minor impact on Earth's climate over a long period of time. It can cause a change in the distribution of sunlight and can also affect the Earth's orbital eccentricity, which can influence the amount of solar radiation reaching different parts of the Earth, potentially leading to changes in climate patterns.

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