---
title: "What would happen if the oceans disappeared?"
description: "Rain would stop, temperature swings would become extreme, and most of the planet's oxygen production would end. The mechanism, what follows in what order, and how co"
url: https://atoneplace.net/what-happens-if/oceans-disappeared/
site: "At One Place"
---

# What would happen if the oceans disappeared?

**What would happen if the oceans disappeared?: Rain would stop, temperature swings would become extreme, and most of the planet's oxygen production would end.**

Reasoned extrapolation

Oceans hold about 97 per cent of Earth's water and drive the water cycle, so their removal would end most precipitation within weeks — rain over land is ultimately ocean water that evaporated. Water also has an enormous heat capacity, and the oceans buffer the planet's temperature; without them, day-night and seasonal swings would resemble those of a desert continent everywhere, with far greater extremes. Marine phytoplankton produce roughly half of the world's oxygen and sit at the base of a food web supporting most of the planet's animal biomass. The exposed seafloor would be a landscape of salt flats and abyssal plains averaging nearly four kilometres below current sea level, with a much thicker column of atmosphere above it. Life on land would follow the water within a very short time.

## How confident this is

This is a reasoned extrapolation rather than an observation. The mechanism is understood, but the scale of the consequences depends on assumptions that could reasonably be argued differently.

## The Earth

- [What would happen if the Earth stopped spinning?](https://atoneplace.net/what-happens-if/earth-stopped-spinning/) — Everything not bolted down would keep moving east at up to 465 metres per second, and the oceans would migrate to the poles.
- [What would happen if the Sun went out?](https://atoneplace.net/what-happens-if/sun-went-out/) — Eight minutes and twenty seconds of normality, then permanent night — and surface temperatures below freezing within a week.
- [What would happen if the Earth lost the Moon?](https://atoneplace.net/what-happens-if/earth-lost-the-moon/) — Tides would drop to about a third, nights would be dark, and Earth's axial tilt would eventually wander.
- [What would happen if all the ice on Earth melted?](https://atoneplace.net/what-happens-if/all-ice-melted/) — Sea level would rise by about 70 metres, redrawing every coastline on the planet.
- [What would happen if all the bees died?](https://atoneplace.net/what-happens-if/all-bees-died/) — Serious, expensive and not civilisation-ending — most staple calories come from wind-pollinated grasses.
- [What would happen if the Earth's magnetic field flipped?](https://atoneplace.net/what-happens-if/magnetic-field-flipped/) — It has flipped hundreds of times already, most recently 780,000 years ago, with no mass extinction attached.
- [What would happen if all the trees disappeared?](https://atoneplace.net/what-happens-if/all-trees-disappeared/) — A carbon and water-cycle catastrophe — but not suffocation, because most oxygen production is marine and the atmosphere holds a huge reserve.
- [What would happen if the Earth spun twice as fast?](https://atoneplace.net/what-happens-if/earth-spun-twice-as-fast/) — A twelve-hour day, more violent weather, and everyone at the equator about 1.4 per cent lighter.
- [What would happen if the Moon were closer to Earth?](https://atoneplace.net/what-happens-if/moon-were-closer/) — Tides scale as the inverse cube of distance — at half the distance they would be eight times larger.
- [What would happen if all the volcanoes erupted at once?](https://atoneplace.net/what-happens-if/all-volcanoes-erupted/) — Sulphate aerosols would cool the planet for years, then the released carbon dioxide would warm it for millennia.
- [What would happen if the ocean currents stopped?](https://atoneplace.net/what-happens-if/ocean-currents-stopped/) — North-west Europe would cool sharply while the tropics warmed — the ocean moves as much heat poleward as the atmosphere does.
- [What would happen if all the insects died?](https://atoneplace.net/what-happens-if/all-insects-died/) — Far worse than losing bees — decomposition, pollination and the base of most terrestrial food webs would fail together.
- [What would happen if the Amazon rainforest burned?](https://atoneplace.net/what-happens-if/amazon-burned/) — It holds well over a hundred gigatonnes of carbon and generates much of its own rainfall — losing it would change climate far beyond South America.
- [What would happen if all the bacteria disappeared?](https://atoneplace.net/what-happens-if/all-bacteria-died/) — Complex life would end within years — nitrogen fixation, decomposition and digestion all run on bacteria.

## Common questions

### What would happen if the oceans disappeared?

Rain would stop, temperature swings would become extreme, and most of the planet's oxygen production would end.

### How certain is that?

Reasoned extrapolation. This is a reasoned extrapolation rather than an observation. The mechanism is understood, but the scale of the consequences depends on assumptions that could reasonably be argued differently.

## Related pages

- [What would happen if the Earth stopped spinning?](https://atoneplace.net/what-happens-if/earth-stopped-spinning/)
- [What would happen if the Sun went out?](https://atoneplace.net/what-happens-if/sun-went-out/)
- [What would happen if the Earth lost the Moon?](https://atoneplace.net/what-happens-if/earth-lost-the-moon/)
- [What would happen if all the ice on Earth melted?](https://atoneplace.net/what-happens-if/all-ice-melted/)
- [What would happen if all the bees died?](https://atoneplace.net/what-happens-if/all-bees-died/)
- [What would happen if the Earth's magnetic field flipped?](https://atoneplace.net/what-happens-if/magnetic-field-flipped/)
- [What would happen if all the trees disappeared?](https://atoneplace.net/what-happens-if/all-trees-disappeared/)
- [What would happen if the Earth spun twice as fast?](https://atoneplace.net/what-happens-if/earth-spun-twice-as-fast/)
- [What happens if you stop eating sugar?](https://atoneplace.net/what-happens-if/stop-eating-sugar/)
- [What happens if you stop drinking alcohol?](https://atoneplace.net/what-happens-if/stop-drinking-alcohol/)
- [What happens if you stop smoking?](https://atoneplace.net/what-happens-if/stop-smoking/)
- [What happens if you stop eating meat?](https://atoneplace.net/what-happens-if/stop-eating-meat/)
- [What happens if you crack your knuckles every day?](https://atoneplace.net/what-happens-if/crack-your-knuckles/)
- [What happens if you swallow gum?](https://atoneplace.net/what-happens-if/swallow-gum/)

## Sources

- National Oceanic and Atmospheric Administration — NOAA (https://www.noaa.gov/) [Public domain (US Government)]