Suppose we, meaning the human race, survive climate change, pandemics, and nuclear proliferation. What then? I’m talking about the long run.

We’ve got a faction who think the Earth would have been better off had we not survived – as if the rest of the ecosystem wouldn’t suffer from the radioactivity or the infections that killed us off.

Then we have the folks who think we should de-industrialize, living lightly on the Earth without high tech weapons or medicines, and focusing on “inner space” (i.e., our psyches). Good for the planet, probably, but we’d still end up fighting with sticks and spears. And all die from an eventual asteroid strike or novel pandemic.

A third faction insists we must colonize space – as if there’s anywhere nearby that’s life-supporting, and as if we could survive the radiation and weightlessness that go with a long trip.

If you’re in the first faction, you don’t believe humans have anything valuable to contribute to life in the universe. Stop reading now. The rest of us can reject the second group’s opinion out of hand, too, right?

That leaves “outer” space as our survival option. There are a number of reasons for pursuing it – some conventional, some wild, some good, some bad:

To capture resources, for use on Earth or for building facilities in space. Necessary, but it carries the danger of even more wealth inequality than exists today. If the “facilities” are satellite-mounted military weapons, it actually raises the chances of our extinction.

For the sake of knowledge and to indulge our urge to explore. Which we must balance against the need for poverty alleviation etc. here at home – and against the fact that we haven’t yet explored our own Earth’s deep seas.

To make contact with alien civilizations. Ha! We haven’t yet learned even to talk with dolphins, our close (compared to green space aliens) evolutionary cousins.

To find/build new places to live. If it’s a simpleminded quest for lebensraum, like the mid 20th century German and Japanese efforts, it’s cancerous. But see the discussion below.

For military advantage. Sad but true.

To have one’s own planet, and be absolute ruler. Elon’s ridiculous fantasy.

Life on Earth is quite vulnerable. We can best hedge against our species’ extinction by inhabiting other worlds or constructed space habitats. We can count on technological progress that will make such colonies (and travel to/from them) safer and self-sufficient.

But now the bigger “Why?” Space is much safer for robots than for biological beings. Why should we risk exposing our bodies to space’s dangers?

Because our Earth is vulnerable to asteroid collisions, solar events, and man-made disasters. And so are we, so long as we live only on one planet.

Obviously we are driven to see our kids, grandkids, and onward survive and thrive. Beyond that, our survival should be motivated by the notion that humans have created (or been endowed with) ideas and values that are so profound as to be worth preserving.

Worth preserving – but not worth forcing on other species! Some readers will immediately think about proselytizing their religions. I ask you to remember the unspeakable cruelty that that activity has brought to bear throughout human history. Other readers will think it means respecting the worth and dignity of other beings. I ask you to remember that in America today we’re still a long way from that ideal.

Literature and poetry? Definitely, but it can be sent to the stars using robots or engraved plates, like the Voyager probes. We’ll put our own bodies and those of our descendants into space because of our continued ability to create still more great art.

Or it could be still other ideas and values – so long as our actions match our words.

Thus we face two tasks: Developing the technologies that will take us safely into space, and, more importantly, figuring out what we’ll take with us.