Existential threats to the human species (colloquially known as ‘x-risk’) come at three scales. The widest-scale risks would sterilize the solar system, at least, as a whole. Next are threats which could destroy civilization due to societal or technological incompetence. And at the smallest scale are risks to Earth’s habitability.
If that ordering seems odd, consider a few examples.
Threats in the first category include gamma ray bursts, nearby supernovae, or the disruption of the solar system following an encounter with a rogue star. None of these are considered particularly likely in the near future, and more importantly are centuries if not millennia beyond our capacity to defend against them.
Threats in the second category include superintelligence, runaway nanotechnology, or the development of new pathogens against which existing organisms have no natural defense. While these may seem differentiated from the first category by their origins, this is not necessarily the case. Natural pathogens are potentially just as deadly as man-made ones. Furthermore, none of these phenomena are necessarily extinction-level events—superintelligences and autonomous nanoswarms may decide that human civilization is not an adversary, and leave us alone. This is particularly the case if intentionally constructed by conscientious researchers. Such possibilities point to a separate class of civilizational issues—coordination problems—but that is quite another post.
Threats in the final category include asteroid strikes and supervolcano eruptions. Arguably, these are the most tractable of x-risks. With asteroids, in particular, early detection would allow us to perturb the body’s orbit sufficiently to pass clear of Earth, potentially decades or even centuries in advance. Supervolcanoes represent a trickier problem—our geoengineering is not so far developed to adequately predict earthquakes and volcanic eruptions, let alone attempt to prevent them. But with continued study over the next few hundred years, that may finally change.
There are two plausible positions on the efficacy of space colonization to mitigate existential risks in the third category:
- The technological and economic challenges inherent in developing independent off-world colonies will take a very long time to solve, so we shouldn’t bother.
- For those very reasons, we should start working on space colonization immediately.
It should not surprise those of you who know me which side of this dichotomy I’m on, but both sides deserve a fairer shake, because the dichotomy is basically false.
For one thing, some money and effort is already expended on space colonization. To be clear, this expenditure is a minuscule fraction of total global production. America spends approximately $19 billion on the National Aeronautics and Space Administration each year, and only a moderate percentage of that total is focused on long-term research1. NASA has a larger budget than any other space agency world-wide, and compared to the Gross World Product of about $75 trillion, we can confidently say that the global expenditure on space colonization is less than 0.03% of the planetary economy.
But even if we halted explicit interplanetary research, the push for more efficient launch vehicles and better medical and agricultural technologies would still represent progress on that front. (Satellite launches won’t end for a long time—you had better believe that Earth observation is critical to managing natural disasters!) When whatever crisis necessitated such a change was finally averted, we would likely be in a better position technologically (if not economically) to pursue off-world colonies.
The crux of the anti-colonization argument, of course, is economics. Can we afford to expend money and effort on space exploration when other problems are supposed to be more pressing? The usual pro-space responses to this question are not terribly good. Let me attempt to give better arguments.
I’ve already made one above, which is that spaceflight consumes a tiny portion of the global production surplus. America alone spends more on education than the world on spaceflight, and it’s not even clear if we’re getting our money’s worth. Those wishing to find the funds for such projects may want to look elsewhere first.
Secondly, the burden of funding astronautics is shifting (slowly!) to the private sector. A few billionaires have gotten tired of competing for the coolest yacht and started competing for the best rocket. Don’t take me for one of the naïve observers who believe space exploration has already been privatized—SpaceX, Orbital Sciences, the United Launch Alliance and all the rest absolutely could not do what they’re doing now without the help of NASA and the Department of Defense, and they know it. But this does represent a shift in the right direction.
Some protest the change on anti-capitalist grounds. I’ve seen a few people say that Elon Musk wanting to colonize Mars is bad, because wealthy individuals would get to escape whatever disaster befalls Earth while the poor perish. I think this objection is foolish for three separate reasons.
Firstly, the sort of person who makes such a criticism is unlikely to support private fortunes to begin with. Obviously, redistribution is their preferred change, but the rich spending their riches on social ends rather than wasting them on mansions is still an improvement. And trying to save humanity is certainly a social end.
Secondly, if a catastrophe does hit Earth, a predominantly wealthy population surviving is still preferable to no one surviving. I have to wonder: do the people who make these arguments entirely appreciate that the question is human extinction?
Let me state that clearly: if you value material equality above the survival of the species, you are no humanitarian.
But the near-term probability of an Earth-only threat coming to fruition is fairly low. In all likelihood, a Mars colony would develop while civilization here continues to exist. Moreover, developing societies from scratch (in multiple locations on Mars, as well as on Luna and the asteroids) will allow us to better comprehend the social problems we’re currently trying to solve. Among the questions that may be answered, will be the role that economic inequality plays in causing other undesirable ends. It may very well be that the billionaires of today are paving the way to something more progressive3.
I don’t think the value of trying out new cultural forms can easily overstated. A major obstacle to solving our problems on Earth is that there’s very little room in which to explore ideas. Succession is illegal in pretty much every country. Taxation and regulation severely limit the space in which experimental communities can be practical4. Of course, Seasteading addresses this particular issue without leaving the planet, but it does not address major planetary risks5, and is unlikely to scale up to the level a colony off-world eventually would.
If we’re taking civilizational threats seriously, we have to decide: colonize Mars sooner or later? To a certain extent, it is an empirical question—what timeline and resource distribution maximizes our odds?—but a question we have to answer on woefully incomplete data.
We don’t know much about the asteroid threat from the inner solar system. We don’t know much about supervolcanoes. We don’t understand the atmosphere well enough to rule out a runaway greenhouse effect. Nor do we understand intelligence enough to predict when or if AI would become a threat, or what the preconditions for a global pandemic are.
For that reason, I advocate increasing work on planetary defense and existential risks across the board—including, yes, space colonization. Now I don’t think that that will be a particularly fast process. Even if landing humans on Mars by 2027 is technologically feasible, founding a colony in the next decade would probably be a suicide mission. There’s just too much prerequisite work to be done.
But that’s true on every front of the fight for our species’ survival. Every year we delay, is a year left to chance. Some argue that the odds are low, because there’s no a priori reason to believe we’re living in a special time6. I reject this argument. There may be no reason to assume that we exist towards the beginning or the end of the human population distribution, but there’s no reason to believe, either, that the last humans will know they’re the last humans until disaster actually strikes. If we’re them (or their parents), well, optimism won’t do us any good.
On the other hand, if disaster doesn’t strike but we’ve cleaned up our environment, created a more resilient infrastructure, developed friendly artificial intelligence, learned how Earth’s interior really works, and colonized the solar system—what a shame. We made a better world, a world that’s now safer and more prosperous than ever, and no threat materialized. Or rather, threats were prevented from materializing.
There’s no deadline, of course, no point after which we’re in the clear. There will always be some risk, even if it’s just from the spontaneous collapse of the universe. But every threat we successfully address leaves humanity better positioned to tackle the next one. Design thorium reactors to end greenhouse emissions, put them in rockets to power advanced propulsion engines. Scale up the rockets we use to deflect asteroids, ride them to Mars. Genetically engineer crops to feed the Martians, send them back to Earth to solve overpopulation. And so on and on, till one fine century we control the stars and save whole systems from destruction.
So let’s get started.
1The vast majority of the agency’s expenditures are on space science2, Earth science, aeronautics, technology research, and supporting operations on the International Space Station. Maintaining a continuously-inhabited station in orbit goes a long way towards preparing for interplanetary missions, but most of the research done on-orbit is focused on more immediate applications such as medicine and materials science.
2Whether lunar, solar, and interplanetary probes count as spending towards eventual colonization probably depends on who you ask.
3I was tempted to write fully-automated luxury communism, but I wouldn’t want to give new readers an incorrect impression of my views. I’m an ex-libertarian more because I support spending 0.5% of the federal budget on space exploration than because I want to nationalize the economy.
4In particular, the requirement to pay county, state, and federal taxes forces more communalist groups to trade on the market, which does nothing to help demonstrate the efficacy of collectivized economic models (or lack thereof).
5That said, Seasteading could prove more environmentally friendly than living on the land. Solar and wind power are practical on such scales, and I doubt seasteaders will waste precious deck area watering grass they’ve no plans to enjoy.
6See Brandon Carter’s Doomsday Argument.