This question comes from Socke, who asks: what would the world be like if the land masses were spread out the same way as now, but rotated by 90 degrees?
It would profoundly alter our world in general and the weirdly Minnesota-heavy world of 1990s cinema in particular.
To be clear – we're not changing the tilt of the Earth's axis of rotation relative to the sun; We're imagining that the Earth's surface slid around by 90 degrees, putting the land under our current poles on the equator, And we'll pick the Greenwich meridian for our new equator, so the Indian ocean is now at the north pole and the coast of Ecuador at the south pole.
Let's imagine that this alternate Earth develops over millions of years, giving time for ecosystems and climate zones to settle out.
Where would the deserts and forests be? And where would you go for a sunny beach vacation or to chase a tornado?
This stuff is complicated, since climate depends heavily on the details of ocean currents and atmospheric heat circulation, But we can make some broad-sweeping speculations based on general climate physics.
The main driver of our weather and climate is the sun, which delivers more heat at the equator than at the poles – Hot air rises at the equator and then flows poleward over our heads, and cooler air moves in across the surface toward the equator.
This circulation is called a Hadley cell. For various complex reasons, earth doesn't just have a single atmospheric cell in each hemisphere – we actually have three: Hadley cells, Ferrell cells, and polar cells.
Let's assume our rotated world has the same situation going on – this means it would have temperature extremes which are similar to ours.
Here's what a map of our rotated earth looks like. We'll add some ice and permafrost near the poles and in mountainous areas.
