Will population explosion drive colonization of space?

With environmentalists and economic development activists ringing alarm bells of population explosion and commensurate resource depletion, provident sights are set on alternative solutions to our growth predicament – including space colonization, either through human settlements, biodomes, or even terraforming, a concept seriously if preliminarily explored by NASA.

But will we really need such extreme solutions? The idea of overpopulation is not new: already in the 19^th century, predictions of a Malthusian catastrophe claimed that Earth would soon run out of resources and its human population would be decimated by famines. These predictions were based on two assumptions: one, that population growth would continue at the same rate; and two, that productivity would not increase. By the 21^st century, neither has proved to be true. 

Firstly, the more affluent a population, the lower its growth rate, be it on account of education, access to birth control, or conscious family planning. The population growth rate remains highest in the poorest and least educated countries – economic improvement strongly correlates with a slow-down, stagnation or even a reversal of population growth. OECD member states, generally considered the most affluent, actually show negative population growth. Even the U.S. nowadays relies heavily on immigration to maintain population growth because families have too few children on average to compensate for natural attrition.

Secondly, the productivity of food resources has vastly improved. It is hard to argue that the human population will soon starve if at the same time 40% of U.S. food supplies goes to waste to the tune of $165 billion a year according to a 2012 NRDS study – European proportions and dimensions are similar. An increasing percentage of agricultural land worldwide is dedicated to the production of biofuel and industrial products instead of foodstuffs for human consumption. Europe in fact pays farmers NOT to produce (but to fulfill their role as gardeners and caretakers of the environment). Swaths of erstwhile agricultural land are being converted into wildlife sanctuaries and forests in Europe. America has even larger unused land reserves. The problem is not that we do not have the capacity to feed the world’s population, now or later – the real problem is and will remain for the foreseeable future to achieve an even remotely equitable allocation of resources.

But even industrial resources are, in fact, far from running out – the threat of an ending oil supply has loomed over us since the Club of Rome made its alarmist announcements and projections in 1972s, and yet, owing to advanced exploration and extraction technologies, new reserves and extraction methods keep increasing, rather than decreasing, our known oil supply, in spite of a significant increase in global oil consumption. Humanity is also resourceful enough to supplant old products with new ones whenever energy resources become scarce – somehow civilization did not collapse because the whale population faced extinction. Whales are still facing extinction but aren’t extinct, either. Similarly, at various times during the last two millennia, there were scarcely any forests left in parts of Europe. But people simply switched to petroleum and natural gas instead of whale oil, they started to use coal instead of wood for heating and stone and bricks for building.

We are not likely to face a need to colonize outer space anytime soon, unless, of course, some easily extractable resources come our way, for example if a new Saturn moon made of rare metals is discovered and we figure out a way to mine there. Pessimists have projected that, at our current rate of extracting and consuming resources under the growth rates prevailing in industrialized economies, we will need three terraformed planets rather than the one we have to keep the human race alive. That projection is, of course, erroneously based on the assumption ceteris paribus, i.e., all other determinants remaining equal. It is arguably impermissibly pessimistic not to take into account the human potential to rationalize, and in some cases to minimize, the need for consumption of resources. A modern combustion engine’s fuel efficiency has increased by a factor of ten in a few decades. New technologies and energy sources may provide for opportunities of change by a quantum leap. Population growth is also closely correlated with religious dogma, a factor likely, but arguably not quickly enough, to decrease with secularization. Yet, it is also likely to correlate with increases in life expectancy as a result of progress in the life sciences. With human ingenuity an infinitely renewable resource unlikely to become exhaustible except under extremely unfavorable organizational forms of major societies, meaningful analysis will likely have to be conducted on a meta-level balancing derivatives of growth rates and qualitative assumptions such as projections of technological development.

The costs in terms of human but also material resources needed to make another planet biocompatible, not to mention habitable, would be immense, based entirely on technology not conceived as yet today, and bear the substantial risk of bringing about, as a collateral damage, the very depletion of terrestrial reserves the endeavor is intended to remedy. Even small-size biodome experiments such as Biosphere 2 show how much we still have to learn before we will be able to so much as attempt creating an artificial ecosystem; the paramount lessons to be learned are not only about the nature around us and the law of unintended consequences, but also, perhaps most importantly, about us as a collective human race.