“Assuming anti-aging science shows results, then all of those hypothetical people living way off in the distant future may include some of us. And if that is the case, then people alive today have a practical, personal reason to care how our current actions impact the future.”
In his 2022 book What We Owe the Future, philosopher William MacAskill contends that we live in a uniquely consequential era. He writes: “Few people who ever live will have as much power to positively influence the future as we do. Such rapid technological, social, and environmental change means that we have more opportunity to affect when and how the most important of these changes occur.”
MacAskill is best known as an advocate for “longtermism,” which posits that we have a moral duty to consider how our actions affect people living in the future. This perspective has many implications for our present-day activities. Most obviously, it means that we should stop polluting the environment because it would be wrong to leave our descendants with a toxic, burning, filth pit of a planet.
Taking the longtermist view seriously, it is impossible to overstate the scope of our moral obligation to future generations. If we do not prematurely ruin our plant or destroy our species, then the number of people who will eventually come to exist will vastly outnumber those who have already been alive.
But we also have the chance—right now—to turn things around and work toward a more sustainable future. The longtermists know this.
Cody Fenwick, writing for 80,000 Hours, does the math on this:
“If we’re just asking about what seems possible for the future population of humanity, the numbers are breathtakingly large. Assuming for simplicity that there will be 8 billion people for each century of the next 500 million years, our total population would be on the order of forty quadrillion.” (Emphasis original)
One near-fatal flaw of longtermism is that it can seem too hypothetical to spur action from people alive today. Even die-hard advocates for longtermism acknowledge: “The reasons we have for improving the lives of those currently alive are emotionally gripping…By comparison, the case for focusing on the longer term feels far more speculative.”
For those who are not already on board with longtermism, it is easy to be deeply cynical about the whole premise. “Sure, there may be people walking these same streets in 3023, but so what? I have my own problems, and they will have theirs. For all we know, they will all be pretentious jerks (a real possibility), and if we could meet them, perhaps we would not care to make things easier on them anyway.”
I sympathize with this critique of longtermism—somewhat less so now that I have a child, but, still, I get it. I have a hard time welling up an abundance of sympathy for people living way off in the distant future.
This critique, however, largely goes away when another in vogue movement is factored in: the longevity movement. This movement posits that aging is a disease and should be treated as such. The ultimate goal is to extend dramatically the human lifespan. If we start making meaningful progress along this path (which we are), then there may be people alive today who effectively achieve immorality through what is called “longevity escape velocity.” In other words, if medical breakthroughs allow us to live just a little longer, and just a little longer still, eventually we will live long enough for science fully to cure aging.
According to Aubrey de Grey, a prominent biomedical gerontologist, “I now think there is a 50% chance that we will reach longevity escape velocity by 2036. After that point, those who regularly receive the latest rejuvenation therapies will never suffer from age-related ill-health at any age.”
The year 2036 is not so far off. Let us say that Aubrey de Grey is a bit too ambitious and is off by a decade. This still gives many millions of people alive today the license reasonably to imagine living for a very, very long time.
Now, apply this to longtermism. Assuming anti-aging science shows results, then all of those hypothetical people living way off in the distant future may include some of us. And if that is the case, then people alive today have a practical, personal reason to care how our current actions impact the future. In the abstract, it is impossible to imagine people living in the year 3023. But it is not so impossible to imagine myself living to 2036—and then a few decades beyond that, and a few decades further on still.
As a species, we can do a whole lot of damage to our planet in a short amount of time— whether through fossil fuel consumption, the use of nuclear weapons, bioweapons, monocrop agriculture, or any number of other reckless activities. But we also have the chance—right now—to turn things around and work toward a more sustainable future. The longtermists know this. And with a few breakthroughs in anti-aging science, we may all be longtermists soon enough.
Peter Clarke is a freelance journalist in San Francisco. He can be found on Twitter @HeyPeterClarke
