Arcologies

"Far? What I have seen would blast ye to a mad statue of stone! Back, back-forward, FORWARD-look, ye puling lackwit!"
And as he snarled the phrase under his breath he gestured anew; bringing to the sky a flash more blinding than either which had come before. For full three seconds I could glimpse that pandemonaic sight, and in those seconds I saw a vista which will ever afterward torment me in dreams. I saw the heavens verminous with strange flying things, and beneath them a hellish black city of giant stone terraces with impious pyramids flung savagely to the moon, and devil-lights burning from un-numbered windows. And swarming loathsomely on aerial galleries I saw the yellow, squint-eyed people of that city, robed horribly in orange and red, and dancing insanely to the pounding of fevered kettle-drums, the clatter of obscene crotala, and the maniacal moaning of muted horns whose ceaseless dirges rose and fell undulantly like the wave of an unhallowed ocean of bitumen.
-"He", Howard Philip Lovecraft, from the collection 'The Road to Madness'

Quoting the Arcosanti page without permission:

'Arcology is Paolo Soleri's concept of cities which embody the fusion of architecture with ecology. The arcology concept proposes a highly integrated and compact three-dimensional urban form that is the opposite of urban sprawl with its inherently wasteful consumption of land, energy, time and human resources. An arcology would need about two percent as much land as a typical city of similar population. Arcology eliminates the automobile from inside the city and reserves it for use outside the city. Walking would be the main form of transportation inside an arcology. Todays typical city devotes up to sixty percent of its land for automobile functions. The miniaturization of the city enables radical conservation of land, energy and resources. Arcology would rely as much as possible on the sun, the wind and other renewable energy so as to reduce pollution and dependence on fossil fuels. Arcology needs less energy per capita thus making recycling and the use of solar energy more feasible than in present cities.'

     The large-scale Arcology movement didn't truly blossom until the early 2020s, spurred by humanity's growing fear and defensive withdrawal from the wild, untamed world around them. It had been several generations since the industrial world was faced, continuously, with the sense of danger and uncaring savagery of the natural world.
     Work in artificial habitats were practiced and perfected with the advent of orbital and Lunar cities. The growth of superstructure buildings and experiments in military defense further developed the technologies needed. By the 2020s, the tools were available to fulfill Man's desire to build a human world.
     Arcologies are generally large surface and underground structures containing small districts. By 2045, New York city consisted almost entirely of 600 massive pyramidal buildings, each a mile high. New York's population was divided between 12 million legal citizens and 20 million illegals at the end of 2041.
     Portals (Gates, from CoC basic book) were vital to transporting resources and wastes away from dense population centers quickly, using MP bought from citizens, or from the processing of captured illegals and criminals. Portals and hypertechnology also allowed arcologies to become very hardened against military action, terrorist attempts, and assaults by various Evils. It was possible, with some of the arcologies, to destroy entire levels of a structure completely and not cause a collapse. Similarly, some designers used hypertech pylons to create the illusion of floating cities.
     By 2050, at least two generations were born of which a significant portion had never been out in the open air.

     In regions with relatively low densities of population there were other types of habitation. Although Arcologies housed a good 20-30% of first world population, there were also underground bunkers, fortifications, as well as more traditional modes of living. There was a growing Techno Nomad movement, of populations that were mobile and equipped with advanced technology.
     Technological growth made humans less and less tied to nature. Food could be produced cheaply in farms utilizing protomatter and biological technologies, while wastes could be processed and recycled with great efficiency.
     Though Arcologies still produced great waste and required huge infrastructure, the technologies formed as a response were key to the survival of other groups. Techno Nomads, functioning with little to no infrastructure, and Mars, which required immense self sufficiency, benefitted. The viability of Mars' future after the End was only possible due to Arcology-spawned technological innovation.
     By the 2040s, a variety of artificial foodstuffs were available. Much like soy before, these substances could be prepared in a wide variety of ways. They could be made with varying nutritional content. Sweets, starches, proteins, all could be combined in a variety of ways and textures. Still, natural foodstuffs remained popular.
     Artificial foods cost, in the 2040s, their same value 50 years previous, or 2.5x 1990s value. Natural produce, such as avocados, pears, potatos, lettuce, and so forth, cost 6-8 times 1990s cost. Seafood is 10 times 1990s cost, and other meats are 15-20 times 1990s cost.