What if we found the way to drain all the Earth's oceans through some mysterious portal at the bottom of the Mariana Trench?

How long would it take? Years? Centuries? Millennia? Would there be any life left on Earth when the pumping was over? What if it happened overnight?

Oceanic water makes up 70% of the Earth’s surface. How much liquid is that, exactly?

This is what the Earth looks like with all the water gathered up.

If we opened a drainage hole about the size of a basketball court, it would take us hundreds of thousands of years to pump out the oceans. They hold over a billion cubic km (321 million cubic miles) of water.

But what if we had a pump powerful enough to drain all the oceans in a minute? What would happen then? Sure enough, swimmers, sailors, cruise passengers – everyone out on the ocean would feel the effects quickly.

Within a second, boaters and swimmers in shallow water would crash into the bottom. They’d get away with a few broken bones.

Deep-ocean ships wouldn’t be so lucky. A Titanic-sized liner would hit the bottom in 30 seconds and smash into tiny pieces. The same thing would happen to just about every large ship within the first minute. What about all the sea creatures?

You already know the answer. It would literally be raining fish since all the whales, dolphins and other big aquatic animals curiously exploring the surface would falling to the ocean floor.

As for those already near the bottom – they’d be lucky not to get sucked down the drain along with the water. And that’s when the real trouble would begin. Our oceans have two life-supporting roles. First – they regulate global temperatures by absorbing energy from the sun.

They push warm tropical waters north and south, and circulate cold waters back to equator. This way no place on Earth gets too hot or way too cold. Global climate control.

Credit: 422South / Vimeo

Second – oceans feed the water cycle, evaporating into the clouds and raining back to Earth. The moment the oceans disappeared, the Earth would turn into a vast desert. Go ahead and throw away your umbrella. Since it’s never going to rain again. Wait, what about all the lakes and rivers? Can’t we get by with those?

Well, without the oceans, the world loses 97% of its water. The small amount of liquid left wouldn’t be enough to sustain the water cycle. The pools of drinkable water would evaporate pretty fast. In a matter of days, people and most animals would die from dehydration.

Plants would have a few weeks before they started decaying in the dry air. Within a few months, forests would begin massive die-offs.

All this dead, dry vegetation would eventually ignite. In the matter of years, most of the world’s forests would be burned down. As these huge bonfires sparked all across the planet, the atmosphere would become less and less oxygenated.

If there were still humans at this time, the unbreathable air and scorching temperature would wipe us out for good. All in all, the Earth would end up just like Venus. Cooked. So why not take a few days off and enjoy a little seaside vacation while you can?

Subscribe to What-If on Youtube or follow the show on Facebook Watch.