What would happen if the Earth's oceans disappeared?

What would happen if all the oceans disappeared from the Earth's surface? What would a world without oceans look like?

What would happen to all the creatures that live in the water? Could humans survive on this planet without the oceans? In the early years of the planet, the Earth was flat. But not in the way you might think. The Earth had no mountains and was mostly covered in water.

Then, about a billion years ago, land emerged from under the sea and changed the planet's atmosphere. This led to the appearance of the first life forms on Earth.

Whether life emerged in the deep sea or evolved in the steamy mud pits of ancient volcanoes, it could not exist without water. Eventually, the planet would heat up, and all the oceans would disappear.

This is not expected to happen for another billion years. But how bad would it be if all the oceans evaporated right now?

Today, the ocean covers about 70% of the Earth's surface. If you poured all that water into an Olympic-sized swimming pool, you would need more than 500 trillion.

If all the oceans disappeared, we would still have some water. The oceans hold 97% of all the water on the planet. The remaining 3% is stored in rivers, lakes, groundwater, and even ice sheets. But that still wouldn't be enough to make up for the loss of the oceans.

The world's oceans act as a global climate regulator. They absorb much of the Sun's heat and distribute it evenly across the planet, so that no area gets too hot or too cold.

They also keep the water cycle going, evaporating into clouds and then returning to Earth as rain. But you wouldn't need to carry an umbrella around in case a big storm comes when all the oceans evaporate. In our scenario, Earth wouldn't be able to hold that much water vapor in its atmosphere. The oceans would leave the planet forever, turning it into a vast, scorching desert.

Marine life would certainly be the first victims in this situation. Then, with no oceans to absorb the heat from the Sun, Earth would slowly burn up, until it turned into Venus.

How long do we have until the planet becomes uninhabitable? The remaining water will evaporate in a matter of days, leaving humans to die of dehydration. Most animals will go extinct without water. Who knows, maybe camels will become the next civilization on Earth ?

After a few days, plants will give up trying to survive without water. After a few weeks, the same thing will happen to our forests. Eventually, they will catch fire and continue to burn until there is no vegetation left.

In about a year, the Earth would be reduced to a charred, lifeless rock. And without water, it would probably never have a chance to produce life again.

Lesley Montoya

Update 21 August 2025