It hasn't "vanished", it is just hiding in the ocean and the atmosphere. Same as the (vanished) water at the icecaps. As the Earth heats, the water evaporates.

It hasn't "vanished", it is just hiding in the ocean and the atmosphere. Same as the (vanished) water at the icecaps. As the Earth heats, the water evaporates. When that happens it adds to heat retention. Expect the water to make a bold reappearance as we experience tropical storms.