How will humanity end?

Extinction by war? Heat death of the universe? Alien invasion? Environmental causes?

I place my bet on death by evolution due to future advances in genetics.

Gamma ray burst, maybe.

I heard it was to be stolen by a thief in the night… any day now.

Asteroid of doom. Already heading this way, we just haven’t spotted it. Could be tomorrow, could be in a thousand years. Or a million. But it will happen. And we will die.

It is certainly possible, but pretty unlikely. The axis of the emission would have to be pointing within a very narrow solid angle of our solar system. Ditto for impact with an interstellar dust cloud.

My guesses would be either radical climate change, making the Earth literally uninhabitable for people (which would require a pretty radical environmental disruption far greater than the projected climate change to date), supervolcano chain eruption which could accomplish the same thing, or a genetically tailored artificial plague. All other possibilities, such as nuclear war, bolide strike, natural plague, famine, et cetera could potentially reduce civilization as we know it to pre-industrial levels but would be unlikely to eradicate humanity.

The other alternative–and the one I find more likely–is advancing to a next, post-human stage of evolution where the natural organic architecture and reproductive process are replaced by a superior technological solution, while retaining consciousness and human ‘thought’. This doesn’t mean transferring consciousness to computers or anything so primitive, but more likely re-engineering the human form to something more robust and enduring while retaining key features such as self-repair and progressive cognitive development. Although “technologists” and science fiction authors have tried to envision what this would entail, I think the real solutions are probably beyond conception at this point, and are likely to be not so akin to “better humans” than entirely new external forms. Certainly it would be far easier for “manned” exploration of space if the astronaut were comprised not of slightly polluted bags of water sensitive to even tiny variations in temperature, ambient pressure, oxygen level, and radiation, but instead hardened shells of robust, self-repairing cognitive networks equipped with their own propulsive power and energy collection and reclamation systems.


The Yellowstone caldera will erupt and wipe out 1/2 of the US within a month from the resulting ash fallout. The material blown into the upper atmosphere will cross the globe and the resulting drop in temperatures and surface sunlight will cause a decade of worldwide crop failures. The survivors will prey on each other for the miniscule remaining food supplies and survival equipment. Packs of dogs will finish the rest of us.


We are talking about a major infestation of almost all areas of this planet by a very adaptable and intelligent species.

Whatever the cause of our global demise would have to be a major extinction level event for much of the other life on the planet too.

<Kosh> In Fire </Kosh>
(Complex-) life-destroying Planet-killer is the only way - whether that be climactic (like, either Snowball Earth or Hothouse Venus) or truly massive impact or runaway volcanism, whatever, that’s the only way to do it. Nothing human-generated is going to cut it, not even global warming or grey goo or whatever.

I think “humanity will end by becoming posthuman” isn’t a real answer.

Take your pick:

You might enjoy reading the 1930 science fiction novel Last and First Men by Olaf Stapledon for the future history of mankind:

By boredom, world-weariness, jadeness and lack of faith. By people not bothering to or don’t see the point of having children.

Yep, has to be that this rock gets deflected off its regular course.

Not with a bang, but a whimper.

Kim Jong-un sends a nuclear weapon against the US, but the navigation system fails and it crashes/explodes in a spot in the Pacific, releasing a massive enough cloud of methane hydrate, and then climate change gets really drastic.

To the sound of thunderous applause!

I haven’t decided yet.

Eventually we will split into one or more distinct new species, and one day the last homo sapiens will die off, probably still stuck here on Earth. The new branches of our tree will continue to thrive somewhere outside this solar system (or within it on geo-engineered planets or moons).

At least, that’s what I like to think. I suppose more likely is that eventually a series of ecological disasters (shifting climate for a few thousand years coupled with volcano and/or large impact strikes and our own perverse nature) will do for us some time in the future. We are going to be pretty hard to wipe out world wide, so it’s going to take a world wide event to really do it right, but that sort of thing happens fairly frequently (geologically speaking) so if we stay on Earth eventually we will be wiped out. C’est la vie.

we already possess theoretical methods of diverting asteroids, we will likely have working models this century.

I don’t think the human race will die. crocodiles have existed for 200 million years, and they have no technology. within 200 years the human race should be advanced enough to be able to survive virtually anything.

By “working models” do you mean actual representative systems which can physically demonstrate diverting large potentially hazardous objects (PHO)? Because there is no current government program or private effort to develop such a system. There are proposals for concepts to develop systems which could theoretically divert a PHO (I’ve actually proposed one myself) but there no significant amount of funding or consistent interest in actually developing and deploying such a system. And the upper range of such as system is probably in the 1000 m diameter solid bolide or 2000 m diameter water ice body. A significantly larger object could not be conceivably diverted with extrapolations of any extant technology. Fortunately, free objects of that size are extremely rare in the solar system as it is constituted today.