Colonizing Earth

Question

After several centuries in exodus, humanity returns to earth to recolonize the planet. Naturally, their first question is the same as mine:

Where are the best place(s) on earth to settle?

Parameters:

• location must be able to facilitate easy access to space
• must be able to maintain a high technology society
• must be able to support a large population in the future (between 250,000 and 500,000)
• bonus if location is near strategic resources (examples: iron ore or oil)
• there are no humans on the planet, so anywhere is a viable landing spot
• assume climate, natural resources, and land masses remain unchanged from the current day -there is to be only one, main settlement

Why my question is different than this one:

• mine is about a human society with stellar technology, not a hunter gatherer society
• mine isn't concerned about creating diverse cultures based on location
• some of the mentioned locations do not meet the criteria I listed above
• this isn't a fresh earth, its the "slightly used" one

Answer 1

Basically anywhere*

location must be able to facilitate easy access to space

Stellar technology implies easy access to large amounts of energy, and therefore the ability to fuel high-energy drives to get into space. While basically anywhere can work, to make logistics and potentially building space access megastructures (if any) easier, I would recommend an equatorial site.

must be able to maintain a high technology society

Especially given that with your tech level, you can make almost anywhere on Earth work, you can do the same as you do on other places to maintain a high-tech society.

must be able to support a large population in the future (between 250,000 and 500,000)

Given the large amounts of energy mentioned, the settlement will be free to use energy-intensive techniques such as desalination and vertical farming, making life support fairly easy, especially given that it seems that your society is able to support a fairly large population in more hostile environments. However, it is important that your colonists set up the space infrastructure needed to maintain said high tech society, such as an asteroid mining network for fuel and materials.

bonus if location is near strategic resources (examples: iron ore or oil)

Your strategic resources will be in space. Using techniques such as asteroid mining, valuable resources will be easy to get to.

If your society can colonize the harsh expanse of outer space, colonizing the Earth should be a piece of cake.

Answer 2

The Korean Peninsula

Let's start with the basics; to support a large city you need water and food. The Korean Peninsula isn't known for its abundance of arable land because of the mountains (but we'll get to those) but there is still enough arable land to support a colony of the size you describe. It's estimated that around 22% of South Korea's landmass is suitable for crop farming (I don't know the figures for North Korea) but that would be more than enough to sustain a sub-million population quite well.

Of course, the peninsula is almost completely surrounded by water (hence being called a peninsula) meaning that you have access to fishing opportunities and your advanced society would also be capable of desalination for a permanent and almost inexhaustible water supply.

This also makes things handy from a launch to space perspective; one of the reasons that Cape Canaveral makes such a great launch site is that rockets are almost immediately over water after their launch, which means if something goes pear shaped you're not raining hell down on your township with the debris. So, you have a good site for launches into space as well.

Now; your society, being advanced, also needs energy reserves and access to metal ores and the like; this is where your mountains come in. Most metallurgy was first developed by societies near mountains because orogeny (the process of mountain creation) lifts some of the ores up closer to the surface, eliminating the need for deep mining to access them. That means that the Taebaek mountain range is going to give you access to a range of different ores and resources, including coal, iron, tungsten and graphite. Note these are not massive reserves, but on the scale you're describing you have access to many of the important resources in relative proximity.

On the North Korean side, you also have access to Uranium, which is important for your energy needs and potentially your space program depending on how you plan to fuel it. Going nuclear would make things a lot easier for your colony, although Russia does have oil reserves, but getting them into Korea isn't as simple as the geographic proximity would imply as I understand it. Still, it's there as another energy source if you need it.

Of more interest is what we call 'rare earths'. These are critical to our modern technologies, especially in batteries and other high energy density applications. North Korea have some of these but as I understand it China has massive reserves of many of these also, and both are within your reach if you locate on the Korean Peninsula.

Ultimately, there are places that will give you some or most of these attributes to an even better degree. For instance, North Queensland has some great potential launch sites, access to 30% of the Uranium on the planet, and the ability to grow a lot of food. If you're prepared to travel a little, you also have access to massive reserves of coal and iron ore. But, you miss out on the rare earths and most of Australia's oil and natural gas reserves are off shore as I understand it.

If on the other hand you're looking for a single location for an advanced colony, you really need those rare earths more than you think which probably makes the Korean Peninsula a better bet.

Answer 3

Stay in space

After generations, the spacegoers are culturally adapted to living in space. They can build and maintain their habitats, can gather resources they need, and can maintain a human society. Else they would have died out.

They already solved all the hard problems of survival.

So settling a planet is optional to them. Nobody alive has lived on a planet before. To them, living in space is perfectly natural.

Their first outposts on Earth must have a direct benefit to the space-based civilization ("hey, we can make a lot of money importing these pretty rocks, and selling them to the rich folks on a habitat").

Subsequent settlements will develop to serve those export industries. ("Hey, if we start a yeast-farm down below to feed the rock-miners, we can really improve our margins over orbit-grown yeast") And then, as inter-settlement trade begins, more industries and settlements develop to serve the growing trade network.

However, most of the population will happily remain in orbit. Some malcontents will hie down the gravity well to the new Klondike to be pioneers, but almost all of the power engineers, yeast-farm workers, schoolteachers, accountants, hull-maintainers, and recycling-plant workers will remain where they were born, and where they want to live their lives ...in the same place their grandparents lived, at home in their comfy space-based habitat.

Answer 4

As 0something0 mentioned (he deserves an upvote for his answer), basically anywhere is suitable for many reasons, however i'm, going to suggest North America for several reasons, however many of these same reasons would apply to a lot of other places

there is to be only one, main settlement

The one main settlement probably somewhere near to the mouth of the Colorado river, i'll call this the Colorado River City, CRC for short

However you're question does not forbid remote sites that could be entirely automated. your populous has survived many centuries in space, its safe to assume they are very technologically advanced and therefore have automated remote sites is entirely plausible. and this comes into my answer later

location must be able to facilitate easy access to space

Anywhere is suitable for space its 100km up, as for getting to orbit... location doesn't effect ability to reach orbital speeds much in the grand scheme, equatorial orbits particularly geostationary orbits are far easier and more fuel efficient from an equatorial location but polar orbits aren't, so it depends on what you're sending up.

Again, there is nothing stopping you from having multiple launch sites spread around and running automatically

But in your world then at least at first, resources are important, so launching over land might be preferable so in the event of a failed launch you could collect it back up from a land based crash site and reuse the base materials.

must be able to maintain a high technology society

Again, location doesn't really effect this that much, especially if you have Automated Remote Sites, but America is capable of being pretty self sufficient, having pretty much all the elements needed from silicon to copper to gold, in plentiful supply, but most of all there is abundant Uranium in the US, as well as plutonium, so Nuclear Power or anything similar is possible with nearby materials.

must be able to support a large population in the future (between 250,000 and 500,000)

The US currently has 320,000,000 people... Nearby to CRC is the remains of San Deigo which at present has a population of 1,400,000 with plenty of arable land available to you, far too much in fact if you used lots of ARS, and there is the Colorado River itself so fresh water is easy to access, and can provide hydroelectric power if needed.

Then of course there's the Pacific Ocean so fish are fairly reliable as well

bonus if location is near strategic resources (examples: iron ore or oil)

Its quite possible, even probable that after 200+ years, any plugs in the current oil wells would have degraded and burst, which means existing oil deposits that have been mined even briefly may well be a lot emptier when your people return than when they left (By no means empty, but definitely not as full). and the surrounding areas would have had a lot of ecological damage, most of which would be ok after a few centuries but it does change some of the important natural resources.

But for the sake of this question lets assume somehow they are ok, well there's Texas and Alaska, both within easy ocean shipping from nearby to the mouth of the Colorado River

As i said, there is Uranium, Gold, Copper etc nearby and also Iron ore, i admit by nearby i'm still talking a large distance but it would be nothing for a spacefaring society. and as 0Something0 (he deserves an upvote for his answer) mentioned space has plentiful materials to mine

But everyone is forgetting a huge natural resource we don't currently use (for obvious reasons) but we'd definitely use when we come back after a few centuries Former Cities!!! with all modern computing and smart phones etc, Gold Copper and Aluminium would be everywhere! just laying around in collapsed skyscrapers these is definitely something that would be exploited

there are no humans on the planet, so anywhere is a viable landing spot

Bargain! but to be honest anywhere is probably not quite right, you wouldn't want to land on top of Everest for example...

assume climate, natural resources, and land masses remain unchanged from the current day

Alas... apart from landmasses, no can do, a few centuries is enough for a lot of things to change without humans messing things up, thankfully most of them would have changed for the better.

But Nuclear reactions that weren't looked after and shutdown early enough in the exodus that made humans leave (and Exodus tends to be suggest a rapid leaving) would have melted down this would have effected the local regions, the oil spills would have effected a lot, etc etc but after a few centuries this damage would already be well on its way back to normal if not completely there, but there may be signs of the previous damage is all i'm suggesting.