MARY LOUISE KELLY, HOST:
What life is out there in the universe beyond our planet, and how long can we sustain life on Earth? These are the two big questions at the center of astrophysicist Adam Frank's new book. It's called "Light Of The Stars: Alien Worlds And The Fate Of The Earth." So, Adam, we got a two-hour show here - plenty of time to cover - what? - all known and unknown universes...
ADAM FRANK, BYLINE: (Laughter).
KELLY: ...Our collective destiny, the fate of the planet. You're up for that, right?
FRANK: Yeah. We can get through it really quick. I'm sure.
KELLY: There we go. Let me start with this number that I read and then went back and reread to see if I had gotten it right. You say that the odds that we, meaning Earthlings - that we are all alone and always were - you put those odds at 1 in 10 billion trillion, meaning you're pretty darn persuaded that there have been other civilizations out there.
KELLY: Persuade me why.
FRANK: Well, so, you know, even 30 years ago, we did not know whether there were any planets around any other stars in the universe. And of course we believe that planets are, you know, the first essential step to getting life and civilizations. But in the last 20 years, we've undergone this amazing revolution in astronomy where we now know that every star you see in the sky has planets going around it and that, you know, if you count up five of them, one of them has a planet in the right place for life to form.
So when you add up all the possibilities in the universe, you end up with 10 billion trillion planets where a civilization could have formed. So that's a lot of experiments that the universe has been able to run. And the idea that none of them except ours went all the way to developing a civilization, you know, kind of strains it a bit. So that's why I think that, you know, we are not - unless the universe is really biased against it, what's happening here has happened before.
KELLY: If you're right and what's happening here has happened before or is happening right now somewhere in a galaxy far, far away. What can life on other worlds tell us about our own fate?
FRANK: Well, this really relates to climate change and then what - this new era that we've pushed the Earth into that people call the Anthropocene, the human-dominated era. And so, you know, as - obviously this is a point of contention in politics, a lot about the debate. But in science, you know, we've known for quite a while that we've been changing the planet.
And from this perspective, what you realize - if you see that there has been many other civilization; we're not the first, all of them probably push their planets into some era of climate change, that it's almost inevitable if you build a world-girdling civilization that's sucking up a huge amount of energy that they will all push their planets into climate change. And then the question is, does anybody make it? Does anybody make it to sustainability?
KELLY: Right. The idea as you put it is basically that if there have been advanced societies out there that have developed, that they would be changing their climates and perhaps have self-destructed.
FRANK: Well, that's the question. So, you know, one of - for me, this perspective, what I call the astrobiological perspective...
FRANK: ...The kind of cosmic perspective on civilizations in the universe - it changes everything about how we think about climate change. We often think we have to, you know, sort of prove to people that we - you know, that we've triggered climate change. From this perspective, the - that question doesn't even really exist. It's, of course we triggered it. Any civilization that, you know, emerges - a technological civilization that emerges on a planet is really a mechanism for harvesting energy and doing something interesting with it - right? - building your civilization, buildings, whatever. And what we really find from when you consider that is that there's no way for the planet not to respond.
So on Earth, we are consuming almost a quarter of the total power that the entire biosphere, the entire collection of life - all the trees and microbes - we consume a quarter of that. How could there not be an effect, right? How could the planet not notice that we're there? So then the question becomes, can anybody make it to sustainability? Can any civilization navigate its transition - its climate change transition and make it through to the other side where you have a long-term relationship with the planet and you're not wiped out?
KELLY: So this is - in a way, I mean, it sounds totally terrifying to think that maybe other societies have been out there, been through this, and we don't know about them because they managed to exterminate themselves. On the other hand, this is a comforting message maybe - right? - that we don't need to have quite the angst about climate change as a political issue because this is completely to have been expected. And the challenge now is, all right, what do we do going forward?
FRANK: Absolutely. I think that's part of the way this perspective really changes the story we tell. What I like to say is that you can't solve a problem until you understand it, and you can't understand it until you know how to tell its story. And when it comes to climate change, we've been telling the wrong story. And part of that story is that we stink, right? Human beings are a plague on the planet.
FRANK: We're horrible. We're greedy. And look; God knows human beings can do horrible things. But in this respect, triggering climate change was not our fault, right? We've been using energy since - for 10,000 years in any form we could find - animal dung, animals themselves - to power civilization. And when we discovered oil, it's not like we, you know, twirled our mustaches and said, mwahahaha (ph), I will destroy the planet. Instead we used it to do amazing things - heating homes, you know, making internal combustion engines.
So triggering climate change was not our fault, but not doing something about it now that we've recognized it, not switching energy infrastructures now that we've recognized it - yeah, not only would that be our fault, but it would be our folly because what it would mean is - is that that would be the reason why we didn't make it across the other side. Some civilizations make it, and some don't. And that would be the reason why we wouldn't make it.
KELLY: But again, is all of this completely hypothetical? I mean, we have...
KELLY: ...No actual proof of other civilizations out there.
FRANK: Part of this revolution in astrobiology and thinking about life and planets together, which we only are just learning how to do, is to look at the history of the Earth, right? The Earth is 4.5 billion years old. There's been life on it for at least, you know, around 4 billion or so.
And the Earth has been many different planets, right? There - for a while, the Earth was a waterworld. There weren't any continents on there. And there's been times when the Earth has been a snowball world almost entirely encased in ice. It's been a jungle planet. There was a time when there was no oxygen in the atmosphere, a long period even when there was life. And it was life itself, microbes that through their - you know, their own living processes made the atmosphere oxygen-rich. And we wouldn't be there without that. All of those have lessons for us about how we have to reintegrate ourselves as part of the biosphere.
We sort of - we've sort of grown up thinking that we're different from the biosphere, and the lesson of this long view, including thinking about possible other civilizations, is that any civilization that makes it has to reintegrate itself back into the biosphere. You can't just push the biosphere around and expect it's not going to feed back on you.
So the real perspective that we gain is we are what the biosphere is doing now just as, like, on other planets that have grown civilizations, that will be what their biospheres were doing. Just like on our planet, you know, there was grasslands, that was the experiment the biosphere was running a while ago. Dinosaurs were an experiment the biosphere was running a long time ago. We're what the biosphere is doing now, but it doesn't mean we're what the biosphere is going to be doing 10,000 years from now.
KELLY: Adam Frank, thanks very much.
FRANK: Oh, it was a real pleasure. Thank you.
KELLY: Adam Frank, professor at the University of Rochester, also an occasional contributor for our show. And we have been talking about his new book. It is titled "Light Of The Stars: Alien Worlds And The Fate Of The Earth." Transcript provided by NPR, Copyright NPR.