Nick Bostrom has a good paper on Astronomical Waste: The Opportunity Cost of Delayed Technological Development, which argues that under most reasonable ethical systems that aren’t completely selfish or very parochial, our philanthropic activities ought to be devoted primarily toward preventing disasters that would cause the extinction of intelligent life.
Some people who haven’t thought about the Fermi Paradox carefully may overestimate the probability that most of the universe is already occupied by intelligent life. Very high estimates for that probability would invalidate Bostrom’s conclusion, but I haven’t found any plausible arguments that would justify that high a probability.
I don’t want to completely dismiss Malthusian objections that life in the distant future will be barely worth living, but the risk of a Malthusian future would need to be well above 50 percent to substantially alter the optimal focus of philanthropy, and the strongest Malthusian arguments that I can imagine leave much more uncertainty than that. (If I thought I could alter the probability of a Malthusian future, maybe I should devote effort to that. But I don’t currently know where to start).
Thus the conclusion seems like it ought to be too obvious to need repeating, but it’s far enough from our normal experiences that most of us tend to pay inadequate attention to it. So I’m mentioning it in order to remind people (including myself) of the need to devote more of our time to thinking about risks such as those associated with AI or asteroid impacts.