The universe's resources (sometimes called the cosmic endowment) is the stock of physical resources in the universe currently accessible to humanity.
If humanity does not go prematurely extinct, the number of people—or moral patients generally—who will ultimately exist is potentially astronomical. These figures are useful for judging the value of work aimed at influencing the long-term future, and in particular for estimating the importance of avoiding existential risks.
Nick Bostrom argues that, barring disaster, Earth will be capable of sustaining life for approximately another billion years. This means that if Earth’s population were to remain fairly close to what is today, then, assuming hundred-year life-spans, the planet would ultimately host about people.
This is not an upper-bound on the possible number of people, however. If humans are ultimately able to colonize other star systems, then they will not be limited by Earth’s ability to sustain life. Given certain assumptions, Bostrom estimates that humanity could eventually reach to stars, which could sustain a total of around biological human beings, or around digital human minds.
Adams, Fred C. (2008) Long-term astrophysical processes, in Nick Bostrom & Milan M. Ćirković (eds.) Global Catastrophic Risks, Oxford: Oxford University Press, pp. 33–47.
Ord, Toby (2021) The edges of our universe, ArXiv, 2104.01191.
Bostrom, Nick (2013) Existential risk prevention as global priority, Global Policy, vol. 4, pp. 15–31.
Bostrom, Nick, Allan Dafoe & Carrick Flynn (2020) Public policy and superintelligent AI, in S. Matthew Liao (ed.) Ethics of Artificial Intelligence, Oxford: Oxford University Press, pp. 293-326, p. 319.