User blog comment:Wijata Mateusz/Imagine a world without the Americas/@comment-257949-20120724091103

If North and South America don't exist? The changes would be incredible. For a start, that means you'd have a single ocean that's neary 17,000 miles wide at the Equator. The distance between Siberia and Northern Europe, going round, would be at least 9,000 miles, getting larger the further south you travel. The significance of this? You have waves with a fetch at least double that of anything in OTL. This means their power will be phenomenal.

Erosion would be insane on Europe's western coastline, and southeast Asia (since the Coriolis effect would mean the overwhelming majority of winds go east in the north and west in the south). More significantly, this also means storms. Very big, very powerful storms. So in addition to sheer wave power annihilating Cornwall, Brittany, the Scottish Isles, Norway, Portugal, and carving out the Bay of Biscay (and on the other side of the world, Indonesia and New Zealand), you'll also have huge amounts of rainfall. These areas would, by today in this world, be very different, if not entirely unrecognisable geographically.

I'd estimate that these areas would be extremely difficult to inhabit. The rainfall would wash away all but the hardiest of crops and the near-constant storms and winds - which could be as much as a perfect storm every day - would tear down most simple structures. The inhabitants of Ireland and the west coasts of Britain, France and Iberia would probably end up building low, resilient stone 'bunkers' if they choose to live there at all, and most likely be sheep grazers.

Looking long-term, the centre of world civilisation would likely be based around the Indian Ocean, and I'm inclined to say it would be more focused on the Arabian Gulf than the Bay of Bengal, if only because as far as I'm aware that area is less prone to cyclones (though who's to say with these massive environmental butterflies?). In addition anyone constructing a TL out of this would find this area slightly more closer to home, if that helps! The Mediterranean would still be inhabited but there could possibly be some effects of wave diffraction through the Straits of Gibraltar which may or may not affect the climate and water conditions around the sea. As a result of the importance of access to the Indian Ocean you might see a very early Suez canal! As for Japan and China, I'm afraid I'm not as sure, though my instinct is to say that respectably-sized waves and storms in Japan would make it less than ideal, and the same goes for most of southern China. Interestingly this puts Korea as reasonably important geographically, due to its stability! Further south in Asia, Indochina, the Philipinnes, and Indonesia would be completely extremely hostile, due to storms and flooding. Australia may be greener, might not be. Equatorial Africa may well be greener, though.

By the time civilisation on this alternate Earth reaches our level, it will have a radically different history to ours, as I've explained, due to the lack of any real possibility of the Western colonial powers able to get shipping out of their storm-battered ports! However, we may well find Portugal, Galicia, western France, Ireland, Norway, Cornwall etc becoming home to a huge industry designed to exploit the raw energy of the Great Ocean, along with a huge tidal barricade in the Straits of Gibraltar to harvest power for the local nations. I also have the strong feeling that due to the tremendous storms of the Great Ocean, the world may still not be circumnavigated.

Now where's my 'threadkiller' badge? :')