What if the Earth Rotated in Reverse? (climate, warm, ice)

[Phil75230]

For sure, two things would reverse directions: the prevailing winds and the ocean currents. This, of course means climates worldwide would shift massively (except near the poles and near the equator - where the effect would be negligible, except for some microclimates in mountainous areas.

The biggest changes would be in the temperate zone and the poleward half of each hemisphere's tropics. To oversimplify things, the east and west sides of continents would switch climates (especially the coastal areas). Similarly the east and west sides of oceans likewise would switch water temperatures. Some deserts would bloom while other "tropical paradises" would be the most literal sense of desert islands. That means civilization's centers would have developed in very different locales relative to our real world.

A lot depends on the shape of the continents and oceans, of course, but on large scale (500 mile / 800 km scales) we can predict roughly how an individual areas' climate would change.

Focusing on North America:

Southern California and South Carolina would switch climates. Metaphorically speaking, the Los Angeles River would be a true, if still small, river, lined with miles of cotton fields. Charleston would be the entertainment capital of the world. I can hear the Mamas and Papas sing "Carolina dreamin' on such a winter's day". Further north, New England / Canadian maritimes and the Pacific Northwest would switch climates. The Nova Scotia Redwoods would be world famous, and ditto for Washington state's fall foliage. With a warm Canaries-Spainsh current shooting westward toward Labrador, even northern Quebec and even Hudson Bay would stay ice-free even in the bitterest of winters.

Further inland, the Great Lakes would be a debatable area, especially in terms of precipitation, but it would certainly have warmer winters than today. Overall, the USA would be a temperate zone version of Australia: well-watered coasts, desert heartland, particularly the South away from the Atlantic coast and the Great Plains. Texas would finally conform to the popular stereotype - just one big desert!

The Intermountain West, percipitation-wise, would be debatable, especially north of Las Vegas, but S. Arizona possibly up to Las Vegas would be well-watered farmland, though it may still get chilly in the winter due to higher altitude. But the Mojave may well become the nation's proverbial breadbasket. Possibly the same for the rest of Nevada and Utah. Lake Bonneville likely would still exist, with cities lining its entire shore.

Your thoughts about this?

[BMI]

Canada’s east coast would a mild winter paradise with very high real estate values.

Vancouver would a quarter of it’s size.

Nobody would be California dreaming

Florida would still be Florida but a bit less humid.

European climates noticeably harsher.

[Phil75230]

Originally Posted by BMI

Canada’s east coast would a mild winter paradise with very high real estate values.

Yep, but with more flat/usable land to go around, it's be somewhat cheaper

Vancouver would a quarter of it’s size.

Probably true

Nobody would be California dreaming

Eh, don't know. The Central Valley would be wetter, not super wet, but still great farming area, won't need much irrigation. California would still have a pleasant, if humid, climate. It might actually gain in this scenario (fewer water shortages, fires)

Florida would still be Florida but a bit less humid.

Florida would be desert, like real world Baja California. Same for the Bahamas.

European climates noticeably harsher.

Yep, especially north of the Alps-Danube line. The Western Med would probably gain overall, even if a bit colder. The Po Valley and inland Iberia would be a miniature American Midwest. To the north, think Siberia, or at best (in W. France and British Isles), Patagonia.

[nei]

climate scientists have done computer simulations of this:

https://www.climate-lab-book.ac.uk/2...rth-backwards/

I'm rather surprised; I thought the east coast of the US would warm, west coast would cool.

for US East Coast:

Perhaps the gulf stream shutdown cancels out the warming from ending most of the cold continental flow. Seasonal temperature range and precipitation would be very different of course.

for US West Coast:

The cold Pacific waters currently keeping the west coast cool but the average temperatures are fairly warm for its latitude. But the colder continental flow [flow over Cascades & Sierra would create a warm foehn effect blocking the coldest air so won't be that cold] must not matter much since the Pacific is currently so cold, so oceanic flow doesn't warm much when the wind direction switches [does it exactly switch?]. Upwelling of cold water should stop if the earth's rotation switch, so coastal waters would get much warmer outside of winter.

East Asia warms a lot; unsurprisingly, it has the coldest winters for its latitude in the world currently so it has the most potential to warm, but does it still have monsoonal flow from the Pacific? Its mainly driven by a Thermal Low on the continent, which should be there regardless of circulation, but the wind direction would still be altered. I'd need to think about this more. The continent highs & low vs ocean would still be somewhat similar to today because continents warm & cool faster but the wind flow around pressure systems would be reverse of today. Would this mean northeasterlies from a Bermuda High?

Gulf stream shutdown + prevailing easterlies from the Eurasian continent rather than Atlantic drastically cools northwest Europe of course. Another interesting find, though of course it's just a model:

North African rainfall went up, and the Mediterranean received so much river input it became almost fresh. The reorganisation of the world’s hydrological cycle that we initiated might have frozen Europe

Norwegian mountains would probably get an ice cap; dunno how big it would be

[Isleofpalms85]

I agree with The study,( the controversial climate simulation done by scientists years ago from the post Nei posted above)the formerly temperate locations would become much more volatile and erratic and unstable, whilst the formerly undesirable climate regions(think Siberia and interior portions of Eastern Asia) would become much more favorable for civilization as we know it, in short, the Plains and Midwest would likely become much colder and drier than they are now, probably those locations would have a climate not unlike modern day Siberia today, Siberia would switch places with the Midwestern United States and would likely be the worlds breadbasket. Just my two cents worth.

[jackierudetsky]

Originally Posted by nei

climate scientists have done computer simulations of this:

https://www.climate-lab-book.ac.uk/2...rth-backwards/

I'm rather surprised; I thought the east coast of the US would warm, west coast would cool.

for US East Coast:

Perhaps the gulf stream shutdown cancels out the warming from ending most of the cold continental flow. Seasonal temperature range and precipitation would be very different of course.

for US West Coast:

The cold Pacific waters currently keeping the west coast cool but the average temperatures are fairly warm for its latitude. But the colder continental flow [flow over Cascades & Sierra would create a warm foehn effect blocking the coldest air so won't be that cold] must not matter much since the Pacific is currently so cold, so oceanic flow doesn't warm much when the wind direction switches [does it exactly switch?]. Upwelling of cold water should stop if the earth's rotation switch, so coastal waters would get much warmer outside of winter.

East Asia warms a lot; unsurprisingly, it has the coldest winters for its latitude in the world currently so it has the most potential to warm, but does it still have monsoonal flow from the Pacific? Its mainly driven by a Thermal Low on the continent, which should be there regardless of circulation, but the wind direction would still be altered. I'd need to think about this more. The continent highs & low vs ocean would still be somewhat similar to today because continents warm & cool faster but the wind flow around pressure systems would be reverse of today. Would this mean northeasterlies from a Bermuda High?

Gulf stream shutdown + prevailing easterlies from the Eurasian continent rather than Atlantic drastically cools northwest Europe of course. Another interesting find, though of course it's just a model:

North African rainfall went up, and the Mediterranean received so much river input it became almost fresh. The reorganisation of the world’s hydrological cycle that we initiated might have frozen Europe

Norwegian mountains would probably get an ice cap; dunno how big it would be

Wait, so is this link saying most of the world is gonna be colder?

[nei]

Originally Posted by jackierudetsky

Wait, so is this link saying most of the world is gonna be colder?

check the map in the link, looks like there's a bit more blue [cooler] than red [warmer]. But there's a lot deep red for East Asia. So the total global average change might be around 0. I found a scientific paper from the same research:

https://www.clim-past.net/7/487/2011/cp-7-487-2011.pdf

doesn't seem to have much details on global temperature change, however