21stcentury 363 agriculture assassination birthcontrol catholicchurch citiesandtowns cityandtownlife civilization climateandcivilization colonization congresses conservationofnaturalresources consumerism consumption(economics) contraception cryonics demographictransition demography developedcountries earth(planet) ecology economicaspects economicdevelopment effectofglobalwarmingon effectofhumanbeingson emigrationandimmigration energyconservation energyconsumption energypolicy engineering english environmentalaspects environmentalconservation environmentalism environmentalpolicy european exploration fiction foodsupply forecasting futurestudies general globalization historians history humanbeings humanecology imaginaryplaces imaginarysocieties immortalism internationaltrade irish lifeonotherplanets literarycriticism london(england) moralandethicalaspects naturalresources nature paris(france) petroleumindustryandtrade planets pol044000soc037000nat011000nat010000his039000tec052000 politicalscience pollution population populationecology populationpolicy poverty powerresources protection publicpolicy religiousaspects renewableenergysources richpeople sciencefiction scottish sexualfreedom shanghaiing socialaspects socialconflict socialscience spacecolonies sustainabledevelopment technology technologyandcivilization telepathy terraformation twenty-secondcentury unitedstates utopias welsh worldpolitics