All of us, with the exception of hedonists, nihilists and goldfish, are in favor of planning for the future. In individuals, we see the ability to put off immediate gratification in favor of long-term rewards as a mark of maturity. As a society, we bemoan short-termism and celebrate visionary thinking.

But how far into the future is it reasonable to plan? 2050 is the milestone by which global warming must be reined in, according to climate action plans from the U.N. and E.U. By the end of the 21st century, the ChanZuckerberg Initiative aims for all human diseases to be cured, prevented or managed. And Elon Musk wants a self-sustaining colony on Mars within 100 years.

But few are thinking longer-term than that—about the future a thousand, a million, even a billion years hence.

After all, critics say, we have enough problems today. What is the point of planning for a world that may never come? Whose potential inhabitants are not suffering—unlike many here and now? Besides, as technology accelerates, who’s to say those inhabitants will be anything like us at all?

But these points, in my view, are actually some of the best reasons for considering the far future—and doing so in fact enhances, rather than diminishes, the urgency of solving major global problems today. Allow me to explain.

I am in the unusual position of having a job that requires thinking on these immense timescales. Part of my responsibilities involve coordinating the Breakthrough Initiatives, a set of privately funded science and engineering programs exploring the big questions of life in the universe. One of our programs, Listen, utilizes some of the world’s biggest telescopes to search for artificial signals from beyond Earth.

If we find one, chances are it was emitted thousands, millions or even billions of years ago. Decoding it will be our most ambitious ever attempt at archaeology: we will be reconstructing a civilization not only very alien but very ancient. And any discussion about returning the call will involve thinking about who not just they, but we, might be when it arrives—in hundreds, thousands or millions of years.

But so far, we’ve heard nothing. It remains perfectly possible that we are the only conscious beings in the galaxy—or even the universe. Yet the Kepler space telescope has taught us that almost all the hundreds of billions of planets in the Milky Way host planets. Even if only 1 percent are habitable, that’s tens of millions of potential homes in our galaxy alone. It is true that with current rockets, it would take tens of thousands of years to reach even the nearest star (though another of our initiatives, Starshot, aims to radically reduce that journey time, at least for small robotic probes). But on a timescale of millions of years, such limitations are insignificant—and spreading throughout the galaxy becomes plausible.

Imagine a future in which we have not only fulfilled Musk’s vision of becoming an interplanetary species, but become an interstellar one. The sheer number of conscious minds that could exist in such a scenario is almost too vast to contemplate. If we care about the 7.7 billion of us on Earth today, should we not care at least as much about the trillions of minds whose existence depends on our survival? Their suffering and joy, their music, art, science and forms of culture that we cannot even conceive of? As for the notion that our distant descendants will be too different than us to matter—perhaps no longer organic—this amounts to merely a kind of biological chauvinism. A mind is a mind, whether its hardware is wet or dry.

But it’s not only conscious minds that we’re talking about. Part of the reason for caring about existential risks, such as climate change, nuclear war or asteroids, is the need to protect the precious diversity of life on Earth produced by billions of years of evolution. Yet how much more diverse would be a galaxy twinkling with life, its forms adapting to environments far more varied than the niches of a single planet?

So existential risk should be thought of as risk not just to our own existence, but to existences whose number, diversity and qualities are almost infinite. And thinking about the far future is not fantasism that shields our eyes from current problems. On the contrary, it focuses them even more acutely on our responsibilities right now.

Of course, there is another reason for considering very distant times and places—one less weighty, perhaps, but still compelling: It’s great fun. There’s a reason that science fiction is one of the most popular forms of writing and cinema: the human imagination is rarely more fertile than when it’s creating new worlds. And those visions have more than once led to visionary new technologies in the real world. Star Trek alone has been credited with inspiring the invention of the mobile phone, the tablet, the GUI interface and digital music files. The inventor of the mobile phone, Martin Cooper, said of Captain Kirk’s hand-held communicator, “That was not fantasy to us. That was an objective.”

So by all means, let’s think about our planet, our societies, our children today—and our grandchildren tomorrow. But let’s also spare a thought, once in a while, for the far future.