The former contributes to and may even drive thermal convection in the deep mantle, and the latter causes changes in the length of day and in the orientation of the Earth's axis of rotation in space.
(The former; contributes; to) (the latter; causes; changes in the length of day and in the orientation of the Earth's axis of rotation in space)
The former the latter
contributes causes
to
changes in the length of day and in the orientation of the Earth's axis of rotation in space