- Solar System Objects
- Planetary Objects
- Planetary Processes
- Planetary Miscellaneous
1. Could the reason for polar ice cap melting be caused more by the change in the Earth’s axis rather than global warming/greenhouse gases?
At the same time the axis of the Earth is moving relative to the stars. There is a 25,800-year precession of the axis of the Earth. While Polaris is now our pole star, in 13,000 years, it will be Vega. This effect is fairly small and long-term. We are closest to the Sun in January, but in 13,000 years we will be closest to the Sun in July, so our winters may be a little colder and our summers a little warmer. There is also a smaller motion of the Earth’s axis called nutation. This 18.6-year motion is due to the precession of the Moon's orbit with this period. Both of these are due to the gravitational pull of the other planets and the Sun on the Earth and Moon.
2. How much does volcanic degassing affect global warming and climate change?