If you can figure out to sustainably and independently live in the vacuum of outer space - such as farming on a rotating space station made of titanium/steel cylinders, at least 2 layered walls rotating/sliding on top of each other (so when a meteorite going 20 miles per second punches a hole through both, the holes get misaligned and the leakage is slow), about 1000 ft radius and 2 miles long, each segment (so that you can evacuate from one isolation unit to another as it goes to vacuum), with many "floors" internally (centrifugal force, i.e. artificia gravity, increases toward the edge as omegasquared-r, so floors can have different speeds, and near the center a fast crazy coriolis force floor for martial arts and near the edge a heavy weight workout room, but the very center weightlessness nonspinning), with a parabolic light collectors casting a shade on the whole cylinder, and piping light through mirrors and conduits near the ends/center of the cylinder inside for farming, and solar panels in abundance to the side for artificial lighting and power (i think solar panels + lightbulbs have lower efficiency of light overall than a polished aluminum parabolic collector), everything fully recycled and autonomous, with outside physical contact only say once a year or every 5 years (and that requires a deadly disease a longer than 5 year incubation period to spread and kill the space station humans if it kills everyone else, and there are such diseases, like syphilis takes a long time for symptoms to develop, and it's called the great imitator diseases), nonphysical social contact such as radio and internet 24/7/365, it would be a pretty livable thing to do. By the way it's only a matter of time to get hit by lightning or by a meteorite by everyone down here on Earth, but the chances are so small that most people make it safely to death. Ditto for a space station, though because of non-meteorite-burning-atmosphere-protection, the chances are indeed higher. Also, at $10,000/lb shipping and handling via the shuttle from Earth, (some people are talking $800/lb foreseeable in the near future) all the construction materials have to come from the not so deep gravity well miracle nearby, called the Moon. So a material extracting Moon base is of paramount importance. I have no clue what the cost of S/H from the Moon would be, but you're probably talking 100x less, especially since, without an atmosphere, continuous acceleration on the ground to a high velocity that shoots off into orbit is possible, and then you don't really need rocket fuel for that, but a nuclear power plant will provide electric propulsion just fine. For a nuclear power plant the cooling is the biggest issue, and it would have to be a geothermal or lunathermal cooling from a mobile platform plant that keeps moving to fresh cold areas as it saturates the underground with heat. Nuclear on the cylinder rotating space station is very difficult, and full electric silicon solar panel is the best option there. The Moon is made up of mostly the same stuff as Earth, on the surface O, Si, Al, Ca, Mg, Fe, Na, K, Ti, and some S, Cl, Mn, P, and then everything else. Though if the center of the Moon is not molten, and the Moon was initially formed from a Massive impact shooting the guts of Earth out into orbit, it might be possible to tunnel all the way to its center without a molten lava around you, and find some Iridium, osmium, platinum, gold, uranium, thorium, etc segregated near the center, if it was in a molten state when it got ejected and had time to stratify, and the ejected part truly came from the center of the Earth, and not from off to the side, if the whole thing came from an impact in the first place. But imagine so much platinum that everyone (7 billion people) could have a fuel cell, and platinum silverware and dishes that never rust. There is lots of stuff to look forward up there, especially lots of real estate and room, and then you can talk humanity numbering in the 100 trillion people or more range, with only 7 billion stuck down on the reservation called Earth, the rest living on cylindrical rotating artificial gravity farming space stations, each couple connected units with a Zoo in it. Having many cylinder space station isolation units living with their own supply of air in the vacuum around them(everyone is breathing and exhaling into the same atmosphere down here on Earth) protects against a global plague/computer-virus-like but genetic engineered real, biological world infection outbreak, and also nuclear war contamination (though it would cut down the meaning of the mutually assured destruction doctrine, i still don't like the way it sounds though) There is theory that eventually the Sun is gonna run out of fuel, though that's a while off. Also there is theory of a technological decline, like the middle ages/dark ages from ancient times, before the enlightenment, and next time it may never recover, so you have to do it when you do have the means and technology, including energy resources like oil, coal , gas and nuclear, of which we may run out of each not too long from now) and once you're stuck up in space living on a space station, you're forced to upkeep and maintain that technology. When the world runs out of oil (and by that I mean cheap oil, because you never run out of oil per se, just the economically recoverable oil part, so once the economics collapses), we may lose all the means to Fly me to the Moon, And let me play among the stars, Let me see what spring is like, On Jupiter and Mars.