Some Monumental News

[Subtitle.] ... involving plate tectonics! Big, if true. (This is not an April Fools' joke!)

This is a crosspost for Some Monumental News by Avram Hiller, which was originally published on Philosophy Happens on 1 April 2025. I have not looked into any of the 2 discussed papers, and I do not think reducing the nearterm risk of human extinction is astronomically cost-effective.

Findings discussed in two recent scientific papers are, given a plausible assumption that I’ll be discussing, devastatingly bad news. On the other hand, if that assumption is false, then the news is incredibly fantastic! As a public service of a certain sort, I will share the news with you and explain why it is so extraordinarily bad. Or extraordinarily good. Frankly, I’m not fully sure which. But it is one or the other, and probably not in between.

Here are the two pieces of bad, awful, terrible news. Or, perhaps, incredibly good news.^[1]

1. This 2023 piece in Nature by Farnsworth et al. argues that in 250 million years, the Earth will be composed of one big supercontinent, Pangaea Ultima, and this will cause climatological effects that will make Earth uninhabitable by all mammals.

2. This 2024 piece in Nature Scientific Reports by Stern and Gurya argues that the Fermi Paradox can be (largely) solved by the fact that virtually all other planets in the known universe do not have plate tectonics, and as such, it is unlikely that large, intelligent life forms capable of sending interstellar signals evolved there.

The evolution and sustenance of complex life on Earth and other planets, according to these pieces, has required a lot of water, a lot of land, and decent enough weather, for a period lasting hundreds of millions of years, for the land to habitable. This most easily occurs on the very rare planet, like ours, with moving tectonic plates.^[2]

This is all quite interesting! And I’ll argue that, if true, they are incredibly momentous.

1. Earth’s long-term future

So what does the idea that there will be an enormous extinction event culminating 250 million years from now really mean? It means that humans and other mammals won’t be around for as long as one might’ve hoped.^[3]3 How good/bad is that?

Let’s assume for the moment that the average life of a complex organism is net good. Despite the ups and downs that accompany mammalian existence - being rejected by your crush, being killed and eaten by a hungry predator (hopefully, in that order) - it is generally better to have experienced some life in the first place. Call this the global happiness hypothesis. I tend to agree with Heather Browning and Walter Veit that there is a good chance that it is correct, though Browning and Veit also argue that we need more investigation into the welfare of animals to be able to have high confidence either way.

What the piece by Farnsworth et al. would entail is that for many millions of years in the near-ish (relative to Earth’s history) future, Earth will lack that good thing, when it could have supported it. This is devastatingly bad news - I would have thought that some advanced creatures would have inhabited the Earth, and had a decent time of it, all the way until the sun makes it too hot for life on Earth a couple billion years from now.

On the other hand, we can hold that the global happiness hypothesis is false - i.e., that human and other mammalian life is net bad. If so, then phew! The horror won’t last nearly as long as we otherwise might have thought.

2. Intelligent life on other planets

You’ve probably heard of the Fermi Paradox: there is no good explanation of why we haven’t seen more signs of extraterrestrial life. There are trillions of galaxies, each containing trillions of stars. Why are we, seemingly, alone?

There are a bunch of potential responses to the paradox. One is the idea that when civilizations become technologically advanced, they reach the point of self-destruction long before they gain the ability to emit radio signals that span galaxies. Call this the techno-disaster possibility.

The techno-disaster possibility doesn’t bode well for us. It seems to give good evidence that we will destroy ourselves before too long. As Eric Schwitzgebel writes, “The most obvious solution to the Fermi Paradox is also the most depressing. The reason we see no evidence of extraterrestrials is that technological civilizations inevitably destroy themselves in short order.” So seemingly, it is good news that Stern and Gurya give evidence against the depressing techno-disaster possibility.

But the Stern and Gurya finding is potentially terrible, terrible news. Some of the worst news one will ever hear, really.

As far as I can tell, the overall wellbeing of advanced life on other planets would likely be no better or worse than it is on Earth, given the nature of evolution and selection pressures. So if the global happiness hypothesis is true, then a universal happiness hypothesis is probably true, too.

And if it is indeed true, then, contrary to Schwitzgebel, the techno-disaster possibility is actually a much much happier scenario than Stern and Gurya’s plate tectonic explanation. Let’s say that there were thousands of advanced civilizations out there, and each and every one of them self-destructed before being capable of interstellar travel. What that means, under a universal happiness hypothesis, is that there would have been, let’s guess, trillions and trillions of advanced beings whose descendants, at some point, destroyed their planets. Destroying one’s entire civilization is really really bad, of course, but is it worse than had advanced life on that planet never existed in the first place? No. Very much not. If humanity destroys the entire Earth in 500 years, is that worse than if life on our planet never evolved in the first place? I’ll take my existence and the existence of billions of others whose species eventually goes extinct over their never existing in the first place, thank you very much.

Of course, the opposite can be said if the global/universal happiness hypothesis is false. You can figure out the details, mutatis mutandis.

Now, the techno-destruction hypothesis does make it more likely that we humans will go extinct, and that’s arguably what’s so bad about it. We want generation after generation of our own descendants to continue for an indefinitely long time!

But we can try to weigh the good of our civilization’s continued existence against the bad of potentially thousands or millions of civilizations never existing in the first place. And that, I think, is not even a close match. I like humans - some of them, at least - but my commitment to our species does not outweigh trillions(?) of other complex species on other potentially habitable planets.^[4]

So, rather than the Stern and Gurya finding being a good thing, it is positively awful, if the global/universal happiness hypothesis is true.^[5] And if the hypothesis is false, then it is amazingly great.

Fate tectonics

What should we say about what has been fated to happen to life on Earth and in the rest of the universe (if the two findings I discuss are true)? I mean, how bad/good do you feel hearing all this? Do you need to sit down and have a drink? Are you right now crying - bawling perhaps? These findings are more monumental than anything happening on Earth right now.

My guess is that you are probably not particularly upset/overjoyed. What does all this reveal about our moral psychology? A lot, I think. I’ll focus on just a couple things.

The vast possibilities of incredibly long-term good/bad described in this post indeed merit a great deal of awe and wonderment. If you are not feeling that, then I think your attitudes don’t fit the news I’ve just presented. Think about all the astonishing aspects of life on our planet, and think about the possibility that trillions of others might be able to be part of and experience similar things. And now, with the snap of the fingers in a piece in Nature Scientific Reports, that is all not happening. Maybe, if the global/universal happiness hypothesis is false, then that’s a good thing, but if it’s true, then it’s a bad thing. But either way, holy shit, there is a whole lot that matters.

There is another incredibly monumental issue tucked within what I’ve been discussing. Set aside the findings about plate tectonics, and just focus on the global happiness hypothesis itself. If it’s true, then voilà! We’ve already had a positive balance of good over bad over the course of millions of years! An amazing amount of good. That would itself be really really fantastic news, if is true. Does it make a difference to you whether there is a lot of happiness or suffering out there in the world, in the past, present, and near-ish future? I sure hope so. Interestingly, the two scientific findings I discuss are only bad/good news against a backdrop of really great/awful news.

So much of our attention gets put on things that we have at least a slight chance of changing, like our current catastrophic political situation. One might reasonably say that that is more worth sweating about than alien civilizations. Indeed, we should still fight the good fight here on Earth. But we should not think that what we are doing now is more than a small blip relative to the much larger potential goods in the universe that we have little or no control over.^[6]

1. ^{^}

   Even though many scientific findings turn out to be false - especially ones that are new and haven’t achieved a general consensus, I’m just going to assume here a high credence that these two are true.

2. ^{^}

   These two findings are a lot more complex, but I’ll leave it at that.

3. ^{^}

   One hedge is that if future humans, or some other intelligent life forms, are around, they could potentially do some geo-engineering thing like sending sulphur dioxide into the air to stop it. Even though geo-engineering has its risks, if the alternative is the extinction of all mammals, then those risks would be worth it. Of course, they would have to keep up with the geo-engineering millennium after millennium, and my confidence that that would happen is small.

^{^}

And besides, the most likely scenario if we don’t the blow ourselves and the Earth up is that some futuristic post-humans will inhabit the Earth. And it’s not clear to me that we have reason to care any more about those post-human individuals on Earth than about alien cultures elsewhere in the cosmos.

^{^}

There is one potential counter-argument: If humans survive to the point where we are able to colonize other planets elsewhere in the cosmos, then there can be billions of civilizations that will exist. Frankly, I think the chances of this are very low. But I’ll leave it as a live, and contrary, possibility.

^{^}

A disclaimer: one might see some resemblance in what I am saying here to ideas that eventually lead to a billionaire comic book-like super-villain pushing for the creation of extraterrestrial civilizations, ASAP. I think that that is a very bad idea, for reasons I might talk about another time. My point here primarily concerns our attitudes towards what is out there, and not our ability to make a difference either way.

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