That is not correct. Positive leap seconds are caused by Earth's rotation rate slowing. Recently the Earth has begun to rotate slightly faster, possibly caused

That is not correct. Positive leap seconds are caused by Earth's rotation rate slowing. Recently the Earth has begun to rotate slightly faster, possibly caused by climate change, which may mean a negative leap second is necessary. https://en.wikipedia.org/wiki/Earth%27s_rotation https://en.wikipedia.org/wiki/Earth%27s_rotation