What would happen if the moon fell out of orbit with Earth completely. Specifically, how would that affect climate, geology, etc.?
Before I answer your question, you should understand that this will probably never happen. Only if a large object like Mars comes close to the Earth-Moon system is there any chance of an event like this happening.
If the Moon did escape from Earth, the main effect would be the lack of tides on Earth. Tides are caused by the differential gravitational force on the equatorial regions: i.e. the region closer to the Moon experiences more gravitational force than the region on Earth away from the Moon. This results in the formation of high and low tides on different regions of the Earth.
Other than tidal forces, there is no other geological or climatic influence of the Moon on Earth. There are issues like no more Moon to light up the night sky, no more solar eclipses, etc. but there will be no change in the geology or climate on Earth.
This page was last updated on July 18, 2015.