Take the following into consideration: Natural disasters, overpopulation, human actions, & events happening in outer space like asteroids.
The biggest problem I see is the amount of fresh water that we have left. However, it would take more of an effort to turn saltwater into freshwater:
The most likely cause of humanity’s extinction is evolution. We will evolve into another species. If we spread to the stars, humanity will all but certainly speciate very quickly. Overpopulation, nuclear war, climate change, and so on? None of those will cause the extinction of humanity. We’re so widespread across the globe that there will be remnant populations. A big meteor strike would do it, but it would need to be bigger than K-T.
Humans are resilient, as shown by the primitive men still flourishing in New Guinea and the Brazilian rainforest. To wipe this species out completely would require huge changes. Even massive habitat destruction might not be enough: while some project that the Amazon basin will turn to desert :eek: other lush forests might arise elesewhere.
Reported for Forum Change.
Apart from Antarctica humans flourished on every continent in times of prehistory. It is a matter of careful study to work out how they got there essentially pre-technology. Global nuclear Armageddon wouldn’t push the population back past where it was only a few thousand years ago. Short of a natural disaster that wipes all life of the face of Earth, some people will survive.
Studies on human genetic diversity - and in particular, questioning why it is so low - suggest that the total human population has previously been driven as low as a few thousand by severe environmental pressures. Much the same studies suggest that entire continents have been populated from a migrating group of less than a hundred. A disaster would need to be of astounding destructive force to drive the species that low. Nearby gamma ray burster perhaps.
[Moderating]
The last three words of the title should be a good clue as to what forum this best fits in. Moving.
My opinion is, if we survive with our civilization intact for the next century or so we, or our successor species will be around for a long, long time. Millions if not billions of years…hell, trillions are possible. The rub is, we have to survive the next century or so, and there are a lot of filters that could take us out in that time frame, the biggest one being ourselves. Climate Change coupled with 1 or 2 additional disasters could do it too. Super volcano is always a possibility, as is a really big rock from space. Natural anti-biotic resistant diseases are another, or some really nasty virus…or it could be something man made that does us in.
But if we get over the hump of the next century or so, and we get out into the solar system in a big way, then I think our species will essentially live forever (either evolving into a series of different species or, more likely, going digital at some point and leaving our organic bodies behind).
I think that there’s a very significant risk that we’ll off ourselves in a not very distant future. We’ve become too powerful for our own good. Scientific experiment unexpectedly going wrong (remember the concern about the creation of black holes in an accelerator some years ago), weapons of unheard of destructive power (doomsday machines, anti-matter bombs, drones killing everything living), engineered germs as contagious as the common cold, more lethal than the black plague, and able to survie dormant for years, and plenty of other hypothetical ways that are sometimes mentioned here and there, plus all the risks we can’t even envision now because we haven’t yet discovered the technology that would make them apparent. Pretty much any kind of dystopia or apocalypse ever envisioned by pessimistic scifi authors is a possibility. Eventually something very, very, very bad is bound to happen in my opinion. We’ll escape one, two, ten, fifty dangers, but the 51st will get us.
I don’t really fear natural catastrophes, but there will be people thinking that the extinction of humanity is a valid option or an acceptable risk for whatever reason in whatever circumstances, and who might have the means to make it happen.
I can’t even envision anything about the long term future of humanity. If we’re still there in merely, say, 200 years, humanity will likely have changed so much already that no prediction can be made. So, 5000 years? 1 million years? It just defies the imagination.
I don’t believe humanity will go extinct. But whatever we evolve into, language will remain. And as long as there’s language, the descendants of humanity will be whining about going extinct in a few decades.
The worst single natural disaster I can come up with would be a nearby gamma ray burst. Put it at the right longitude, and it could instantly wipe out 6 billion. If it’s at low latitude, the follow-on climactic effects might be able to wipe out somewhere around 90% to maybe 99% of those who are left.
But that would still, even in that worst case, leave us with ten million humans in the Americas. There are plenty of species with populations that low that are doing just fine. And within a few years of the burst, the rest of the planet would be capable of supporting life again, so it wouldn’t take us long to expand back. Heck, most of our infrastructure would still be there waiting for us, in good shape.
What would dying in a gamma ray burst feel like?
I can think of two scenarios that might wipe out humanity:
a plague. Think something as deadly as HIV but as contagious as measles. (With a long, asymptomatic incubation period.) It’s possible a few individuals would be immune and find each other to repopulate the earth, but it’s possible they wouldn’t. Once upon a time, a remote population would have survived, but now that people fly all over the world, it seems unlikely that an epidemic could be kept out of a significant population center.
A giant meteor, like the one that caused the KT extinction. Even if a few people who were spelunking or something when it happened survived, what would they eat?
You don’t need to be spelunking to survive a dino-killer meteor. You just need to be a thousand miles or so from the impact location, and have a few years of food available. Humanity passed the point where that would finish us thousands of years ago.
SicksAte, the initial deaths wouldn’t feel like anything, because you’d be dead before you had a chance to know it. The follow-on deaths would mostly be from starvation, plus some freezing, or violence from other humans making sure that they’re not the ones who starve or freeze: It’d be the same sort of nuclear-winter effects as from a meteor, though through a different mechanism.
What’s the mechanism of death? Basically a massive instantaneous radiation burn? What would be left of a body?
The radiation from a GRB is not enough to harm anybody at ground level, so mostly it would feel like starving to death in a nuclear-winter like scenario.
This is false. The gamma radiation wouldn’t reach the earth’s surface. There would be a increased short spike of UV radiation at ground level, but likely not enough to cause harm.
As mentioned before the real killer would be the NO2 smog, choking out visible light, yet causing sustained increased harmful UV due to ozone depletion, plus acid rain.
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My take: Humanity will have its ups and downs, but we will last as long as plants are able to photosynthesize. The realistic threats there would be massive gamma ray burst at low latitude, impact of a meteor around 300 meters in diameter, or supervolcanoes. If we don’t have plant life then we have nothing to eat, so we’re done.
I don’t think it makes sense to talk about an evolutionary successor to humanity. Our intelligence and adaptability reduces the need to evolve much. Take for example food allergies… any other species that suddenly developed allergies to its staple foods would quickly die out, but humans can work around such pressures. We may edit and change ourselves but we’re never going to evolve like other species have done.
Of course if some cosmic event sucker-punches us to where we’re reduced to bands of a few hundred hunter-gatherers… even then I don’t think we’ll evolve, but it might open up a continental playing field for another species to step up. Like it would be interesting to see what would happen if every human in Australia got whacked but they released all the elephants from the zoo first. I’m rooting for the elephants.
The UN’s report on biodiversity posits that we are on the verge of a massive collapse in our ecosystems. I suspect we will be close behind unless the idiot conservatives and fundamentalists get their heads out of their asses and start supporting things like species conservation, alternative energy, and support for climate change remedies.
In my more pessimistic moments, I find myself glad that I’ll live out my lifespan before it becomes a catastrophe, because I don’t see the idiots being enlightened any time soon, and they’re running the asylum these days.
“Not with a bang but a whimper” is also my guess. We’re already running out of options for antibiotics, with superbugs shrugging their shoulders at our best options. I’m guessing a pandemic caused by some sort of very tough airborne virus.