There’s been a glut of post-apocalyptic media to come out in recent years – everything from Mad Max, to Jericho, the Fallout series, The Walking Dead – all purporting to show us a decimated human race trying to pick up the pieces after a disaster has wiped out nearly all of us.
My question is this – despite what TV and video-games tell us, will there always be a surviving class of humans? Aside from our sun going supernova, are there any known apocalyptic events that could occur that could feasibly wipe out 100% of humankind, but leave the planet itself relatively intact?
A huge asteroid strike or super volcano eruption might do it but it still wouldn’t kill everyone right away. It would take a scenario with the secondary effect of blocking out sunlight and putting earth into a deep freeze. That would still take time (months, years, or more) to kill off the last survivors if it ever could. The only other threat that I can think of is some type of super bacteria or virus that kills every person it encounters. No such examples are known however and that still has the issue of reaching people that live in isolated places as well as random immunity in some individuals.
A highly infectious avian-type “designer” airborne flu is the closest thing and too much geographic isolation across the planet to ever wipe out an entire species.
A persistent (dormant in the environment until it can infect) pathogen which inflicts 100% sterilization on its victim would do the trick. The youngest generation infected would be the last generation of humanity, except for isolated pockets. These would become infected in subsequent generations as they spread out into infected areas, wiping out the remainders.
It wouldn’t be instantaneous, but it would be thorough.
Not only that, but it would be hard to detect - in the sense that you could be a carrier and not show it.
Whenever I think of apocalyptic scenarios I’ve never really thought of anything quite like that. I want to say ‘kudos’ for the interesting idea, but we are talking about the elimination of human beings…so somehow that doesn’t seem appropriate…
The asteroid strike might do it right away. I’ve seen computer sims of an asteroid the size of Japan hitting the earth on some documentary or other. The strike liquifies the crust of the entire planet within a few hours. Life might survive that (apparently there’s some weak evidence that unicellular life has, in the distant past), but no human is going to, unless they happen to be on the moon at the time.
You’re talking about something astrological, like a solar radiation burst, massive coronal flare, or asteroid strike. Most other scenarios (disease, war, etc) would all leave at least a handful of people alive. Even a pathogen with 100% mortality rate would fail to find a vector to carry it to some isolated jungle tribes. Any such event would have to effect the entire world.
Because of their great intelligence and physical adaptability humans may be
the most likely of all chordates to survive come what may. The chordate phylum
is about 500 million years old. Assuming that the most recent 500 million years
are representative of the future then no disease, meteor strike or volcanic eruption
is ever going to wipe us out, and it is hard to imagine any peril originating within
the solar system which could wipe us out, as long as the Sun retains its present state.
If you eliminate the “leave the Earth intact” requirement, you could always go for a false vacuum scenario. That would wipe out all life on Earth, and probably the Earth itself along with a good chunk of the cosmos. It’d do it right quick, too; by definition, we’d never see it coming.
I wouldn’t count “killing all life on Earth” as “leaving the planet intact.” (EDIT: although I guess in retrospect I don’t know what the OP meant by that.)
I think the OP is talking about a scenario that could lead to the Life After People specials. You know, human beings are all gone, but everything else is perfectly intact.
The only thing I could think of that possibly could fit that would be a virus that:
Has a long incubation time. Long enough so that it can reach remote locations like Tristan da Cunha, which has a population of about 300 and is only visited once a year by ship. (Which means an incubation time in years, or even a decade)
Only infects humans (leaves the environment intact)
Is 100% fatal to those infected
I don’t think such a thing could exist naturally. Perhaps a very talented genetic engineering company could produce one, given a few decades and enough human subjects to test it on. Perhaps.
As a note: if you did manage to kill off everybody except for those on remote islands like Tristan da Cunha, I believe as long as less than about 5,000 individuals remain, humans will be extinct in the long-term any way. There wouldn’t be enough genetic diversity to keep us going more than a few generations.
On the other hand, it’s 2012, and all those remote communities can use radio to contact each other and meet up, which might bring the total breeding population to a high enough level to keep humanity going.
Not only can we survive a bottleneck of that magnitude, we probably already have - Youngest Toba eruption - Wikipedia
Certainly I can think of no reason under ideal conditions why 5000 modern human beings wouldn’t be enough. (edit to add, if they know about the catastrophe and spread out within a reasonable period - leaving them all on one island is less than ideal)
Tangent. That would make an interesting SciFi novel or movie. What would humanity do if it knew it was the last generation? Would we still go about our jobs, wars, and save money for the future? What would happen to the economy, medicine, research, religion? There would be a “last person born”, and eventually, a “last person alive”. Presumably, the rest of nature would persist as humans decline, so the world would be intact. I wonder what people and society would do if it was known that there was no future beyond our own lifespans.
Indeed. I’m interested in scenarios in which humankind has died out in total, but the planet itself continues to spin. This would eliminate any scenario in which the Earth was entirely consumed by fire, crushed by a massive meteor, etc.
