Why is our planet rotating faster? Scientists don't know

It would appear the Earth has sped up a little bit, and we may need some "negative leap seconds" to keep our artificial system of measuring "time" in order. The folks measuring the speed with which our planet rotates have some ideas, but no conclusions, as to why this may be happening.

NDTV.com:

On July 29, the Earth broke its record for the shortest day as it completed a full spin in 1.59 milliseconds less than its standard 24-hour rotation.
According to the Independent, the planet recently has been increasing its speed. Back in 2020, the Earth saw its shortest month that has ever been recorded since the 1960s. On July 19 of that year, the shortest of all time was measured. It was 1.47 milliseconds shorter than a typical 24-hour day.

The next year, the planet continued to spin at a generally increased rate, but it did not break any records. However, according to Interesting Engineering (IE), a 50-year phase of shorter days may be starting right now.

The cause of the differing speed of Earth's spin is still unknown. But scientists speculate that this could be because of processes in the inner or outer layers of the core, oceans, tides or even changes in climate.