Please note I borrowed the following question from lakepowell.net
and I am surprised to find that Geologists dont even mention the possibility of Vulcanism in some way affecting climate!!! Is this possible? Is it possible that the biggest part of our planet, the sub-surface core does not in any way affect the cycles of the climate?
Is it possible that the sub-surface itself is affected by “constructions” like the Milankovitch theories and Solar Cycles etc etc?
What causes Climate Change?Although the basic causes of climate change are still not fully understood, many clues have been collected. Possible causes include: (1) Tectonic Causes
- Landmass distribution: Shifting continents (continental drift) causing changes in circulatory patterns of ocean currents. It seems that whenever there is a large land mass at one of the Earth’s poles, either the north pole or south pole, there are ice ages.
- Undersea ridge activity: “Sea floor spreading” (associated with continental drift) causing variations in ocean displacement.
(2) Astronomical Causes
- 21,000 year cycle: Elliptical orbit of the Earth around the Sun (precession of the equinoxes)
- 41,000 year cycle: Cycle of the +/- 1.5° wobble in Earth’s orbit
- 100,000 year cycle: Variations in solar energy output
(3) Atmospheric Causes
- Heat retention: Due to gases such as carbon dioxide and methane in Earth’s atmosphere– the “greenhouse effect”
- Solar reflectivity: Due to clouds, volcanic dust, polar ice caps
We can also separately consider climate changes over several different time scales:
- 1) Long term (millions of years);
- 2) Medium term (thousands of years);
- 3) Short term (decades to hundreds of years).