No need to reset your watch yet, but redistribution of ocean mass could make days a fraction of a second shorter in the next 200 years.
Global warming likely will shorten the length of the day by about 120 millionths of a second during the next 200 years, according to scientists Felix Landerer, Johann Jungclaus and Jochem Marotzke from the Max Planck Institute for Meteorology in Hamburg, Germany.
According to an article summary, warming water will transfer ocean mass from deep areas to shallower areas around continental shelves, a change that will mean more of the ocean's mass will be near the Earth's axis of rotation. And, because of the wonder that is conservation of angular momentum, that would speed up rotation--as in the case of the figure skater pulling arms and legs closer to the body, as the American Institute of Physics points out.