What would happen if the Earth stopped spinning?

A point on the equator moves at about 465 metres per second — roughly 1,670 kilometres per hour — and everything on the surface shares that motion. If the planet stopped abruptly, the atmosphere, oceans and everything loose would continue at that speed, which is the catastrophic version of the question. If it stopped gradually the sequence is different and stranger: a solar day would become a solar year, giving six months of daylight and six of darkness with enormous temperature contrasts. Earth's rotation also maintains an equatorial bulge of about 43 kilometres, and without it the planet would relax toward a sphere, allowing the oceans to migrate toward the poles and leaving a continuous equatorial landmass. The magnetic field, generated by convection in the liquid outer core organised partly by rotation, would very likely weaken substantially, removing much of the shielding against solar wind.

What happens, in order

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 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? 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? Sea level would rise by about 70 metres, redrawing every coastline on the planet.
• What would happen if all the 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? 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? 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? 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? 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? 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? 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? 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? 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? Complex life would end within years — nitrogen fixation, decomposition and digestion all run on bacteria.
• What would happen if the Earth stopped moving in its orbit? It would fall into the Sun in about 65 days.