"Nature" paper: Increased polar ice melt caused by global warming may affect global timing. Melting ice in Greenland and Antarctica may be slowing Earth's angular velocity faster than before.
To do this, Coordinated Universal Time (UTC) may need to add a negative "leap second" 3 years later than it originally was. If the melting of polar ice does not accelerate in recent years, then negative leap seconds will need to be added three years earlier. This would cause problems with computer network timing.