Would humanity survive a major extinction event?

I’m talking about things like the K-T extinction event, which wiped out 75% of Earth’s species, including all non-avian dinosaurs, or the Permian–Triassic extinction event, which killed off 96% of Earth’s marine species and 70% of its terrestrial species.

It’s not clear why these extinction events occurred, but the predominant theories seem to be that there were major impacts by meteors or comets, or an increase in volcanic activity. Either way, the resulting dust in the air would block sunlight, kill plants, and destroy ecosystems.

If such an event happened now, would humanity survive? Obviously civilization would probably collapse, and there would be widespread food shortages. But our species is spread throughout the world, are omnivorous, and are resourceful. Plus there are the paranoid survivalist types with several years worth of food hidden away.

Am I naively optimistic when I think that humanity could get through something like this?

I’m posting this in Great Debates because I don’t think there’s a factual answer.

Preparation would mean a lot. If we knew an impact was coming that we had no hope of diverting, but had ~4 years to prepare, I’m certain at least a few thousands of people in government underground facilities would survive in the short term. A big question would be how long until agriculture becomes possible again. If it’s only a matter of a few years, seeds and hydroponic gardens could be kept alive. If you’re talking several decades before the Earh comes out of an impact winter, that would be more dicey.

I would mention that a lot of what made things like the K-T (K-Pg if you’re hip with the new stratigraphy) and the end-Permian events so definitive wasn’t necessarily just the magnitude of the events which sparked them, but rather a global ecosystem that was already apparently in stress (for example, dinosaurs were declining millions of years before the K-T event) and that the cataclysm was merely an aggravating factor that turned what would already have been a minor extinction event into a major one. But this seems to imply that a cataclysm alone isn’t enough to cause mass extinctions.

So if the question is merely, would humanity survive a large impact, large scale volcanism, etc, the answer I think is pretty clearly yes. Personally, I think that the whole notion of humans going extinct is pretty unlikely-- we’re just about the most adaptable species out there this side of cockroaches. I could see populations returning to pre-historic levels (into the thousands), but I think total extinction is pretty unlikely, barring the extinction of all life on Earth.

The answer to this question is ‘Depends’.

Would we survive the Moon crashing into the Earth? No.

Would we survive a massive famine? Maybe.

I guess it depends on how you mean extinction. Obviously our ancestors HAVE survived extinction events.

If you look at the terrestrial megafauna that survived the KT event, it was creatures that were semi-aquatic and lived near rivers, like crocodilians. Presumably this was the ecosystem with the quickest recovery. So, if you want to survive, go live near a river. And learn to fish.

Given enough electricity, we could.

An impact winter essentially just means that we’re receiving less energy from the Sun. Plants require this energy to live. Herbivores require plants to live. Carnivores require herbivores to live. Omnivores require some of all the former to live.

Using artificial lights, we would be able to maintain all of our farms and pastures. We would be able to heat our houses and cars. It would be terribly expensive and require some time to make and set up proper equipment, but even in the worst case, we could get some farms going and hence some people staying alive. I’d imagine that areas closer to the equator would have better luck.

So I’m not alone in thinking that we could survive it.

So what would it take to wipe us out? A solar flare? Snowball Earth? Nearby supernova? Nuclear war? Super pandemic?

Good question - if we have an event that prevents the growth of food, we’re fairly well screwed, but there is always the cannibalism option. I think the thing that would put the human race down for good would be a sterility problem.

How many ways do we have to grow food? It can be grown in soil outside, but hydroponic farming done 1,000 feet underground and powered by geothermal or nuclear energy is also possible.

Can we grow vats of algae or bacteria and live off of that?

Anyone seen the masters of horror episode called the screwfly solution? Its about aliens that want to exterminate humans, so they release a toxin that gives men religious delusions telling them to kill all the women.

Nuclear war would be much worse than an impact because you would have the deliberate destruction of much of civilization’s infrastructure, plus the unique threat of fallout.

A pandemic would depend on a lot of things. Even before modern medicine plagues were horrible but seldom really threatened to truly eradicate the population. The Black Death was the only plague that actually made a blip on the population growth chart. What modern medicine has done with sanitation, vaccinations and antibiotics is to sharply limit the communicability of many diseases. Plagues spread by body lice for example would spread much less than formerly. A modern pandemic would have to be viral, airborne and difficult to vaccinate against. Whether or not genetically engineered hyperbugs with a 99+% mortality rate can really be developed would make a big difference. The biggest question would be at what point a sufficient death toll would disrupt society, as social conventions broke down because of fear of contagion.

In fact I would broadly say that almost any cataclysm in which society however beleaguered could keep functioning would survive (think the Soviet Union during WW2); whereas anything that disrupted the machinery that keeps nearly seven billion people working to produce and distribute food would quickly destroy most of the human race.

The Yellowstone ‘supervolcano’, should it blow, would cover half or more of the US in volcanic ash like Pompeii. There would be nowhere to grow food. The rich would bug out for foreign lands and the rest of us - ?

I remember reading that Stalin, when considering a first strike nuclear war against the US looked at the fact that so many people in the USSR had died from political violence, war & famine and he took that to mean that the nation could survive a nuclear war too if they survived all of that. I don’t think he was even considering the deaths from WW1 and the Russian Civil war. But if you add those in the period from 1914-1945 was pretty much one of endless death in the USSR. The first world war & the Russian civil war killed about 10-20 million. Stalin from 1924-1953 killed another 50 million via pogroms and famine. WW2 killed 25 million. But the nation still survived.

I think humanity is pretty much past extinction at this point. Even if you kill 99.9% of us, all it takes is the other 7 million to record much of our scientific data on microfiche and hard drives, and then start up again.

That’s why I think the sterility virus is the way to go - something that is undetectable, doesn’t injure the host, but is contagious and causes sterility in everyone it infects. Transmission by every possible method would be required, too. I think humanity could survive just about anything but that.

According to some folk (or wiki, at least) we already have done. That event might have reduced the human population to around 10,000. All it takes is for one village in Tibet, or a couple of hamlets in the Tierra del Fuego to scrape through and we’ll be fine in the long run.

Sure, we’d just field-promote some captains and…

… what?

Us folks who live outside the US, in foreign lands, are a part of humanity too.

But we’re causing a mass extinction event right now, by reducing habitat for wild plants and animals. The global ecosystem is stressed now.

Solar flare: no. Those can knock out power to large areas and kill maybe a few thousand people. Not even close. They also have the disadvantage of only affecting half the Earth at most.

Snowball Earth: not likely to happen while the continents are in the configuration they are now. Continents clustered around the equator is the configuration most favorable to a snowball Earth. (Of course, after this past weekend, maybe the snowball Earth is starting now…)

Nearby supernova: possible, but unlikely. They have to be really nearby to do a lot of damage. There are, AFAIK, no immediate threats (meaning: in the next few thousand years) from Type II supernovae (supernovae from massive stars). Type Ia supernovae (supernovae from white dwarfs) are more of a concern, since they’re brighter (so can affect us from farther away) and white dwarfs are harder to find than massive stars.

If nothing else happens, in a billion years or so, the oceans will evaporate as the sun gets brighter. If something like humans is around then, they’ll have to find someplace else to live.

Personally, I wouldn’t want to survive a cataclysm like the dinosaur extinction. We might be fine in the long run, but the standards of living immediately afterward would probably make today’s Third World hellholes look good by comparison.

It goes without saying that the first years would be dreadful, but really, once stabilised, would reverting to the 16th or 17th century be so bad? At least in the short term. Providing we retain the Scientific Method and the importance of cleanliness, then humanity will recover soon enough.

For me it would. I’d have no useful skills. As far as growing food goes, I managed to kill a potted mint plant once. I have heard that this is impossible, but I did it.

“Animals could be bred and slaaaghtered!”

“Our big breakthrough since last summer has been the confection of a certain virus omega. Total infertility! In plants and animals. Not just disease in a few herds, Mr. Bond, or the loss of a single crop. But the destruction of a whole strain. Forever! Throughout an entire continent.”

Tell me you have a fluffy white cat…