SuttaCentral
If we wipe out all life on Earth, what happens to re-birth?
And if re-birth continues in other realms, does that mean some will be trapped forever in Saṃsāra? My understanding was that one had to re-born as a human to have the possibility of liberation.
If we wipe out all life on Earth, what happens to re-birth?
Rebirth will continue in other realms. In fact even right now everything you experience is just your wandering mind, so it will just keep wandering in constantly changing mind states as it is doing right now.
Also, it is possible that somewhere in the ocean of the vast cosmos even right now there is a planet with “human-like” life, that we have not or cannot discover due to the [cosmological horizon] (Cosmological horizon - Wikipedia). But what could be a barrier for space-time travel or scientific discovery, could not be a barrier for rebirth process.
Same principle would apply for animals.
And if re-birth continues in other realms, does that mean some will be trapped forever in Saṃsāra? My understanding was that one had to re-born as a human to have the possibility of liberation.
I remember Ajahn @Brahmali on many occasions saying that dhamma is taught not only in human realm. Also Buddha was teacher of both humans and gods, so devas and brahmas can hear and practice the dhamma as well.
‘That Blessed One is perfected, a fully awakened Buddha, accomplished in knowledge and conduct, holy, knower of the world, supreme guide for those who wish to train, teacher of gods and humans,
Anyway, as long as you have dhamma now in your mind, you can continue practice in your next rebirth as long as your intellectual/spiritual capacity of your body allows that. Thats why gift of dhamma is so wonderful.
Thats also why reborn Anagamis are brahmas who know the dhamma and finish the journey in brahma-loka and realise full Nibbana from there.
Also, eventually sometime somewhere in the cosmos will emerge human-like life again, so the opportunity to practice as human being will arise somewhere in the ocean of time and space.
Relevant sutta:
“Bhikkhus, suppose a man would throw a yoke with a single hole into the great ocean, and there was a blind turtle which would come to the surface once every hundred years. What do you think, bhikkhus, would that blind turtle, coming to the surface once every hundred years, insert its neck into that yoke with a single hole?”
“If it would ever do so, venerable sir, it would be only after a very long time.”
“Sooner, I say, would that blind turtle, coming to the surface once every hundred years, insert its neck into that yoke with a single hole than the fool who has gone once to the nether world would regain the human state. For what reason? Because here, bhikkhus, there is no conduct guided by the Dhamma, no righteous conduct, no wholesome activity, no meritorious activity. Here there prevails mutual devouring, the devouring of the weak. For what reason? Because, bhikkhus, they have not seen the Four Noble Truths. What four? The noble truth of suffering … the noble truth of the way leading to the cessation of suffering.
“Therefore, bhikkhus, an exertion should be made to understand: ‘This is suffering.’… An exertion should be made to understand: ‘This is the way leading to the cessation of suffering.’”
This happens in Buddhist cosmology as part of the cycle of the world’s formation and destruction. When the karmic merit of gods in higher realms expires, they are reborn in lower realms to repopulate them.
I guess we could also add that at some point Buddhists accepted the idea that there are innumerable worlds that exist besides our own to which beings could be reborn. I’m not sure if that notion was ever used to explain where beings are reborn when the world is destroyed, but it would make sense as an idea to fill that gap of logic.
This assume that only Earth can sustain life. There can also be a time difference between those in other realms and here.
Were neanderthals and other extinct human species part of the human realm? Perhaps the dividing line between human and animal is not so clear cut. Even among our own species we exhibit wildly differing body types and mental capacities.
At the end of the aeon, when the world is destroyed:
At a time of contraction, beings are mostly born in the Ābhassara Brahma world. DN 27 Aggañña Sutta.
Commentarial opinion is divided on the meaning of “mostly”. The commentary interprets mostly as meaning, that beings are also reborn in higher brahma realms or formless realms. But the subcommentary states that beings can be reborn in other world systems which aren’t contracting. Apparently, this is due to the “problem” of beings that commit ānantariya-kamma (killing one’s mother, father, an arahat, wounding a Buddha, splitting the Sangha)at the end of the aeon- the subcommentarial position seems to be that they can be reborn in the hells of other worlds. See Gethin, Cosmology and Meditation, 1997, pp198-200.
Anyway, that is the end of the kalpa. If everyone just dies due to other reasons, that’s an open question.
As for we humans who are a part of all this, who lived and did nothing and pretended it would all go away: we shall become hungry ghosts, wandering lost over the ashes of the world we ruined, crying in confusion, seeking forgiveness, and condemned to know that all this was our fault.
This…
If we define ‘Life’ in our modern terms as being restricted to Forms…then yes, life on Earth began, and it will end.
However, Sentience, in the way the Buddha defined it, is not restricted to the aggregate of Form. Sentient Beings ‘exist’ based on craving…they cannot be ‘destroyed’.
Only when the factor of Ignorance is replaced by Wisdom is the idea of a sentient being seen for what it is… a lump of foam, a magic trick… It never really existed in the first place, did it?
Thank you all for your helpful and thoughtful answers.
A lot of the answers say - basically - the system will still be in place.
That may be true, we might not break the system so to speak. It seems hubris to think we humans could break the system - it is far bigger than us.
But I do wonder if the consequences for where we humans go in that system could be quite dire.
Maybe it won’t be business as usual for us. Escape from rebirth might no longer be possible for humans.
I think it’s an incredibly massive hubris that humans think they can do that. Incredibly massive. Life will go on as long as there’s a planet and a star shining on it. Life probably exists under the ice of moons circling the frozen depths of space the way it does far beneath the surface of the earth and at the bottom of the oceans. Where there’s life, there’s evolution of life as it discovers the limits of what’s possible. And it’s a very patient thing, life.
I’m glad you agree with me on this point. I have to admit I find it the less interesting point.
I find it more interesting that all the responses to my question except one emphasize this “business as usual” view of life and Buddhist cosmology–life will go on in some form or some realm, and in that new form or realm we can advance towards liberation.
Everyone but Bhante @Sujato has not explored the path that we may not keep going as usual if we destroy ourselves as a species. That there might be great consequences for our ability to escape rebirth if we destroy our species, and many other species along the way.
Many of the answers seem to me a bit over-confident.
It isn’t exactly life as usual… if samsara is without discernable beginning or discernable end, then samsaric existence/suffering will also be without discoverable end…
If beings ‘throw away’ their chance at advancing towards Liberation in this life - then that is, well… stupid and deluded 
But isn’t that the entire problem? Not being able to see reality as it is, beings pursue Dukkha thinking that it is Sukkha.
We’re used to thinking about ‘squandering’ the opportunity of this birth, on an individual scale, but you’re quite right, by destroying the favourable conditions/ this planet, the population or’ collective humanity’, is squandering an opportunity for future rebirths on this planet > increasing the interminable time of samsaric existence… awaiting the arising of other favorable conditions, including another Buddha to proclaim the Dhamma.
So, summon all the samvega you can, and get to work!! 
Added: The job isn’t to fix samsara, but to eliminate Craving.
The Path is elimination of suffering/liberation from samsara, via the eradication of craving. It must necessarily go in this order. - Samsara can only be ‘fixed’ by the ultimate destruction, cutting off, obliterating… of craving.
That’s the beauty of Eastern thought, isn’t it? There is no eternal damnation, no person (or species), no matter how evil is ever totally without merit… Nothing lasts forever. Even the worst of us will eventually have their shot at redemption, although they might spend an eon in hell beforehand… Yes, even Zuck!
I like to keep my mind open to what’s really possible rather than reduce things to absolutes. A good reading of history suggests that civilization can break down and go backwards, the population can be reduced greatly, and it can get very bad if I think about it. But the end of all life on earth? This is just as extreme and unlikely to me as to think everything will carry on as normal. Reality is messy and not really given to staying inside the lines we draw with our minds.
(Hmm, that kind of rhymed!)
That’s good, but I’m not sure why you position it as if in answer to me. Unless I’ve forgotten a passing comment of mine, it doesn’t really respond to anything I’ve said in this thread. I never brought up the issue of probability of us wiping ourselves out. I never brought up the issue of all life on Earth. We had a long thread on the likelihood of all this, which I have no interest in re-hashing.
Edit: Ah, I see the problem. In my original post I did say wipe out all life on Earth. I had been thinking wipe out our species, not all life. So some answers that confused me make more sense now. My bad! Carry on! Nothing to see here!
I posed a hypothetical - what if we wiped ourselves out as a species - and asked how that would work from a Buddhist perspective.
My surprise was that, with the exception of Bhante’s response, the replies seemed a bit complacent. I’m not sure if that reflects that commenters are considering my hypothetical in a slightly different way than I am, or whether I am uncovering an aspect of Buddhist thought I don’t fully understand and need to explore more deeply.
It would create an interesting challenge to carry on all philosophical discussion limericks.
It’s worth remembering that the number of sentient organisms on Earth has varied wildly over time. Of course, there was a period in which there was no life at all (or even no Earth!). There is good reason to believe that there were far more sentient organisms in the Carboniferous period when the world was much hotter and wetter than now. Perhaps the period with the fewest organisms after life took hold was in the Snowball earth period when ice covered most of the planet. We are probably somewhere between those two periods now.
By the way, it’s highly unlikely the even a large-scale nuclear war would wipe out all life. Deep sea organisms would be unlikely even to experience a bit of sloshing from all those fathoms above.
The finer aspects of kamma and rebirth?
As per my current understanding, Sentience (aka a Mindstream) has to be thought of as not just being restricted to the Human species per se, but as migrating between different forms and realms based on maturing kamma. The Mindstream is not a real entity either… it consists of various empty factors continuously arising and passing away based on sense contact. At the time of death in one form (eg as a human) the mindstream seamlessly rearises again in another form and realm (rebirth eg as a peta ghost/ animal/ brahma god) based on kamma and the craving and clinging factors which were prominent at the instant of death/rebirth. Thus, it does not matter if the human species gets wiped out or not, or even if all Life as we know it is destroyed… the Mindstream of those last humans will be reborn in the surviving animal forms or in the hell/ peta ghost/ heaven realm … Samsara will not end. … and after some eons, there will be another kalpa (world cycle), another Buddha, another chance for these very same Mindstreams to gain Nibbana! Not quite business as usual, but not quite the end either.
To reiterate, the Mindstream is not a fixed entity/ Self - it is just an identification label on a set of continuously changing mental factors. Nothing migrates between the two forms on either side of the Death/Rebirth divide… but the mindstreams of the two are linked. The classical examples are of a river passing from the mountains to the plains, or of a series of lamps being lit sequentially. I personally prefer a more modern example- I think of the Mindstream as a process within a networked system … when node A fails, the process seamlessly rearises in node B. If we examine the Mindstream process in node B closely, we find various mental factors (prior knowledge such as past life memories or more prosaically Talents - prior skills in music or whatever) that certainly were not acquired in node B, but are leftovers from the time in Node A.
Thank you for this…it gets to a question from my husband who is not Buddhist but curious and asking questions. He was wondering how a lesser evolved animal like a worm or even a farm raised animal like a chicken…how the consciousness stream in them would have a chance of rebirth as a higher being. I was explaining that kamma is about volitional action and intention. If an animal doesn’t have enough consciousness to make choices how do the build enough good kamma to move “up”?
The only answer I can think is that they don’t…there’s just a waiting for causes and conditions to change enough that a human life becomes available…?
Thanks for sharing your knowledge!
That is exactly what makes Samsara so fearsome and what should propel one who has heard the Teaching to achieve at least Stream Entry within this very lifetime…
AN1.333-377
the sentient beings who die as animals and are reborn as humans are few, while those who die as animals and are reborn in hell, or the animal realm, or the ghost realm are many.
If one has bad enough kamma to be born in the lower realms, it is extremely difficult to get out … such beings have to wait till their bad kamma gets exhausted and some previously done good kamma comes due for fruition… this could take eons! Sometimes of course, even an animal may have enough sentience to make good kamma.
AN10.216
Sentient beings are the owners of their deeds and heir to their deeds. Deeds are their womb, their relative, and their refuge. They shall be the heir of whatever deeds they do, whether good or bad.
In the face of those intent on global destruction, unwilling to heed reason, the following isn’t exactly complacent:
SN35.88:16.1: “If they take my life with a sharp knife, I’ll think:
‘There are disciples of the Buddha who looked for someone to assist with slitting their wrists because they were horrified, repelled, and disgusted with the body and with life. And I have found this without looking!’
That’s what I’ll think, Blessed One.
That’s what I’ll think, Holy One.”
SN35.88:17.1: “Good, good Puṇṇa!
Having such self-control and peacefulness, you will be quite capable of living in Sunāparanta.
I actually find it rather fearlessly badass. No ghosts there.