The Trump administration has expressed an interest in space development, with some talk of moon missions and even a mission to Mars. While I disagree with Trump on most matters, I do agree that the United States should commit considerable resources to developing a meaningful presence beyond earth. This would include the creation of colonies.
One of the stock arguments for establishing colonies off world is the survival argument. Those who believe in the scientific evidence are aware that there have been numerous great extinctions on earth and there is no reason to believe that humans are exempt. There are a variety of doomsday scenarios that could effectively end humans as a species, ranging from asteroids to atomic war. Less extreme, but still of concern, are disasters that could destroy civilization without exterminating humans.
The survival argument, obviously enough, is that having a large enough population of humans off world would allow the species to survive such disasters. In the less extreme scenario, the off-world human population could preserve civilization and help restore it. These scenarios are quite familiar to readers of science fiction.
From a moral standpoint, the obvious argument that we should go off-world to ensure survival is a utilitarian one. The gist is that while there will be a large cost in expanding into space, this is offset by the utilitarian value of increasing the odds that humanity and human civilizations will survive in the face of global disaster. This sort of ethical reasoning, made famous by J.S. Mill, involves weighing the positive and negative value created by an action. The action that creates the most positive value (factoring the negative) for the beings that count is the right action to take.
The obvious moral counter, which is also utilitarian in nature, is to make the case that the resources that would be used to expand into space would be better spent increasing our chances of survival here. While the obvious concern is climate change, even those who reject climate change can make the case that there is a multitude of threats on earth that need to be addressed. These range from flooding to the corona virus. The case is typically made in terms of the return on investment. For example, spending billions to create a moon colony would provide less benefit than spending billions addressing terrestrial threats to survival.
While this is a reasonable moral argument, one obvious counter is to point out that spending on space development need not exclude addressing terrestrial problems. After all, we already expend vast resources on matters that do not increase humanity’s odds of surviving (and some that decrease it). There is also the practical fact that buy-in is needed from those who control the resources and it seems more likely that the Trump administration would fund a moon base than fund anything relating to climate change. As such, while the “the money is better spent on other things” argument has some viability, it is certainly not a special threat to spending on space.
Another reasonable objection is both moral and practical: expending vast resources and morally justifying them based on survival is flawed because we lack the technology and resources to create a viable survival option. While some might use the story of Adam and Eve as an inspiration, creating a viable and self-sustaining colony in space that could keep the race going or even preserve civilization in the face of a collapsed earth seems incredibly unlikely. The colony would need enough population to be viable and would need to be able to maintain its existence without any assistance from earth. As such, it would need to grow its own food and produce its own water, air and equipment. Think of how difficult it is for humans to operate in the Antarctica—operating a colony on the moon or mars would be vastly more difficult.
A sensible counter is to point out that this would not be impossible—it would just require a massive investment and perhaps centuries of effort. Which would, of course, take us back to arguments about effective use of resources.
A third good objection is to argue that humans are poorly suited for survival off world. We obviously cannot survive in space or on any of the other worlds in our solar system without the proper life-support. Laying aside obvious concerns about air, food and water, there is also the matter of gravity. Humans, at least the current model, would not do very well in low gravity.
One counter is to argue that the moon and mars might have enough gravity to make them viable for human habitation. There is also the option of using spin, as in sci-fi, to create “artificial” gravity in orbital habitats. Another counter, which is rather radical, is to argue that we can modify our species to live in such environments through genetic engineering and technological augmentation. Life on earth shows a remarkable ability to adapt to incredibly hostile environments and it is reasonable to think that humans could be altered to be able to survive in conditions that would be harmful or even fatal to stock humans. For example, there might be a way to modify human beings so that they handle microgravity well. Getting into the realm of science fiction, I can imagine radical alterations to humans ranging from complete biological reconstructions to putting human brains into mechanical bodies.
Such proposals do raise serious questions, including the question of what it is to be human. After all, imagine a person so extensively modified that they could do short EVA work on a spaceship just wearing shorts (for modesty), a tool belt and magnetic boots. Would such a person still be human? This raises the concern that going into space for survival might be impossible: if we must cease to be human to survive, then humanity would end with the earth whether we went into space or not.
One approach to this concern is to argue that it is not the biology that matters, but some other factors. For example, it could be argued that as long as the “space people” have cultural and moral ties to “human people” then the survival of the “space people” would mean the survival of humanity, if not homo sapiens. As a closing objection, there is the classic judgment day problem—one that I recall from my first space arguments as a college kid.
The gist of the judgment day argument is that God has planned for judgment day, perhaps as laid out in Revelations. On this view, humanity is perfectly safe on earth—nothing can happen that could interfere with judgment day. So, there is no point in expanding off earth for the purpose of survival. There might be other good reasons to expand into space—such as finding aliens to convert or to do good works for the glory of God, but the survival argument would have no weight on such a world view. The challenge is, of course, to prove that this view is correct.
My overall view is that while the survival argument has merit, it requires taking an extremely long-term view—getting a self-sustaining colony that could survive the end of humans on earth would presumably take centuries. Since I can take the long view, I do find this argument compelling.