A couple of years ago the earth was spinning slightly faster than at any time in the past 50 years by about a few parts in 10-9. Since then it has slowed down a bit. This indicates that either the earth’s moment of inertia has slightly decreased and then increased or that a torque has acted on the earth’s mantle. It is well known that the earth is experiencing global warming. There are good calculations of the forcing of the climate due to the energy in long wavelength radiation emitted by the earth being less than the energy in short wavelength radiation from the sun absorbed by the earth. This paper addresses whether and how the changes of earth’s rate of rotation and global warming are related. The melting of glaciers increases the earth’s moment of inertia and thereby reduces the rotation rate of the earth. In addition this paper proposes a mechanism that results in the heating of the interior of the earth due to the earth’s loss of rotational kinetic energy. This may result in either an unexpected increase or decrease in the rotation rate of the earth.

One result reported in this paper is that the thermal expansion of the earth’s oceans results in a very small increase in the earth’s sea level and moment of inertia compared to the increase in the sea level and moment of inertia due to the melting of earth’s glaciers and ice caps. Previously results reported by the Mitrovica group at Harvard have shown that at the present time global sea-level change is driven primarily by glacial melting.