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 is slid around by 90 degrees, putting the land that's 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 is 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 weathering climate is the Sun, which delivers more heat at the equator than at the poles.

So hot air rises at the equator and flows poleward over our heads.

Then cooler air moves in across the surface toward the equator.

This circulation is called a Hadley Cell.

For various complicated reasons, Earth doesn't have just a single atmospheric cell in each hemisphere, we actually have three.

Hadley Cells, Ferrel 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.

Next we should fill in some green areas and deserts.

The locations of these depend heavily on rainfall, so we'll need to sketch out some winds.

Because of the Coriolis effect, the surface winds in a Hadley Cell flow not just toward the equator, but from east to west.

In the temperate zones, the prevailing surface winds are west to east, and at times there are also east to west winds circulating around the poles.

So let's fill in some wind patterns, keeping in mind that in reality, things would be further complicated by land interactions and the locations of persistent high and low pressure systems.

The rising air at the equator carries moisture from the ocean, which then condenses into rain.

So tropical areas are usually wet and thick with growth.

Sinking air is cool and dry, so the land under the outer edges of the Hadley Cells tends to be arid.

These regions, lying a bit poleward of 30 degrees, are known as the horse latitudes for some reason.

In temperate zones, things are more variable, since Ferrel Cells aren't as strong as Hadley Cells.

Weather there is dominated instead by the movement of jet streams and fronts, and it also depends heavily on geography.

Just for fun, here's a wild guess as to where the hurricane basins might be.

And for more fun, here's a guess about what time zones would look like.

New York City, notably, stays in the same time zone and is still subject to hurricanes.

Sorry.

Let's take a closer look at each continent.

North America's climate is similar to before, but flipped north-south.

Central America is now icy and polar, while Arctic Canada becomes tropical.

Hurricanes threaten Greenland, Baffin Island, and the Maritimes.

Tropical moisture from Baffin Bay and the former North Atlantic mixes with cool air flowing down from the Rockies, creating a new tornado alley in the prairies inland from Hudson Bay.

South America looks sort of like the old Europe.

It's cool and temperate along the Brazilian coast, with grasslands and boreal forests along much of its width.

In the south, the boreal vegetation gives way to polar tundra, and eventually to the massive ice-bound Andes, which cut the continent off from the frozen polar waters.

The Amazon, which in our world carries more water than the next seven rivers put together, is reduced to something akin to the Mississippi.

Asia is flipped in the same way North America was, with the Siberian coast now facing an enclosed tropical sea.

The Indian subcontinent and former Southeast Asia form the new Siberia.

The Gobi Desert is no longer in the rain shadow of the Himalayas, but it doesn't exactly become tropical.

Europe resembles the old Southeast Asia.

Great Britain and Ireland look like the islands of Sumatra and Borneo, Iceland resembles our Philippines, and Central Europe is the new New Guinea, with the Alps the only place on the equator with permanent glaciers.

Africa is rotated by 90 degrees, with former West Africa becoming tropical rainforest and former East Africa an arid desert.

On our Earth, North America has by far the most tornadoes of any continent, but in this world, I bet they'd be frequent in Africa as well.

Australia is cooler and wetter, with forests along the formerly dry western regions.

But Antarctica is the clear winner.

Without its ice cap, it's a bit smaller than we remember, but most of it is blanketed with highland rainforest.

There are alpine zones around the mountains to the south and west.

The researchers at McMurdo and Ross Island work in a tropical paradise.

If any of them decide they miss the frozen wastelands, hey, they can always put in for a transfer to Costa Rica.

Now let's check on how the world's largest cities fare.

Some get colder.

Mexico City, high in the polar mountains, is buried beneath an ice sheet.

Jakarta is the new Svalbard, a desolate coastal rock too far north for even most Norwegians.

Kolkata and Delhi are icebound, sealed off from the warmer world by the Himalayas.

Hong Kong, Manila, Karachi, and Mumbai are similar to our world's Anchorage or Reykjavik.

The ocean isn't frozen solid, but it sure is cold.

Many cities remain comfortably habitable, albeit with some changes.

Seoul, Osaka, Tokyo, Shanghai, and New York City are among the least affected cities, with climates roughly similar to their previous ones.

Shanghai does get colder, but seasonal extremes in all five cities get milder, particularly in Seoul, and substantially wetter.

Cairo has moved slightly south.

It's now surrounded by coastal savannah with spots of rainforest found around the mouth of the Nile.

Sao Paulo and Buenos Aires cool down a little bit.

Their climate is somewhere between that of our old New England and that of our old regular England.

Los Angeles is cool and mild.

The steady sea breeze carrying moisture up into the San Gabriel Mountains makes L.A. one of the rainiest places in the new U.S.

It closely resembles a wetter version of our Seattle.

And a few cities get much hotter.

Moscow is extremely hot and very dry, with a climate somewhere between our Phoenix and our Baghdad.

And London sits in a steamy jungle with a climate generally resembling Bangkok's.

Spicy curry is now climatically appropriate, the Thames is full of piranha, and it's the only place on Earth where tigers apologize as they attack you.

At the beginning, I mentioned the impact on 1990s cinema.

To explain, let's consider one more scenario.

Namely, what if this change were made to our Earth essentially instantly, rather than naturally over millions of years?

We're assuming that all the material has magically shifted around, so there are no massive tsunamis or earthquakes.

Even so, it would definitely still be a catastrophe.

The ice caps would melt long before new ones could develop, pushing the ocean up by a few hundred feet.

The reshuffling of climate zones would come as a huge shock to the biosphere, leading to ecological chaos and possibly mass extinctions.

But, if the shift happened just right, and if Michael Bay were telling the story, then, as the waters of the Gulf of Mexico began to cool, and the Mississippi slowed and became an estuary, the region's wildlife would spread inland.

And one morning, all those Minnesotans we know from 90s cinema would wake up to the sight of floating rafts of fire ants, followed by 5 million lost, hungry alligators, who would wallow in the mighty duck's now-melted skating rink.

Add yet more for the characters in Grumpy Old Men to complain about, and lead to a similarly gruesome, if more reptilian, ending to the movie Fargo.