Everyone seems to be latching on to the idea that the entire surface of the earth was exposed to a global firestorm after impact. I don’t think there is a scientific consensus on this. As bad as a year-long winter followed by still substantially reduced average global temperatures would have been, I’ve got to believe that enough humans who weren’t caught up in the immediate after-effects of the strike (a localized incineration of flora and fauna) would figure something out to ensure humans weren’t completely wiped off the face of the earth.
If the entire planet is immolated, then as already mentioned upthread, you’ll lose all plant life and therefore all breathable air. At that point you may as well be colonizing Mars.
But I don’t wanna be a Morlock!
I disagree, and blame movies like Interstellar for spreading this misconception. Even if all the plant life and all the animal life were lost, and the atmosphere became unbreathable, Earth would still be a vastly superior place to restart life. It would still have an atmosphere (so no need to worry about pressure containment boundaries being punctured and leading to near-instant death for everyone, also the surface would be explorable with just oxygen masks), it would still be closer to the sun and in the temperate zone, and it would still have literal oceans full of liquid water. Oh, and the Van Allen Belt.
And that’s just the first few that come to mind. I’m sure there’s lots of other fringe benefits that would come from having the remnants of human civilization close at hand (like scavengeable construction material, roads, simple tools, etc.).
In short line, the best hope humanity has of surviving in space is the Earth itself, even after a global cataclysmic event, and even if we come up with some sci-fiesque technology like anti-gravity propulsion. Think about it. If you can create an enclosed ecosystem capable of sustaining hundreds of people as they traverse the void of space, how many more people you could support in an equally enclosed ecosystem on or beneath the surface of the Earth/oceans with so many fewer challenges to face?
It will not, IMHO, for as long as Homo Sapiens are likely to exist, ever be more cost effective to lift large segments of the human population off the Earth than to sustain an equal (and likely much greater) population of humans on the Earth.
I wasn’t saying that it would be the equivalent of going to Mars, I was saying it would be roughly equivalent to the task of surfacing from deep underground on Mars since you can’t breathe the air either way.
Fair point on the pressure, though. So maybe it would be more akin to Venus?
There’s plenty of oxygen in the Atmosphere.
You seem to be thinking in terms of the asteroid or comet that formed the Chicxulub crater and arguably killed the dinosaurs. It’s estimated to have been 11-81 km in diameter and made a 150+ km crater. There’s a couple other big craters that get close to or overlap the very bottom part of that size range. The video up top is estimates of what happens if we get struck by a 500 km diameter body. It’s a whole different kind of hurt .
Of course we don’t have any evidence of anything remotely that big striking us in the last 4 billion or so years. To give it a little perspective, we’ve only got about a billion years left till the sun cooks us all anyway as it ages.
Only half the diameter of Ceres!
ETA: I think we’d at least see that one coming.
I was responding to the video and to the OP, which postulated
On taking a second look for cites, I realize that most of the ones talking about multiple millions of years are talking about return to pre-disaster levels of diversity. For instance:
But what we’re talking about here isn’t a return to full normality, but just a return to being able to find something to eat. So it does look like that would be less than millions of years – but it might still be a lot longer than we’d be at all likely to survive to see:
The headline is that life returned “surprisingly quickly”; but they mean “quickly” in geologists’ terms:
which reads to me that at least in most areas it took tens of thousands of years for any significant life to reappear on land.
Even after an impact as depicted in the video upthread? The entire earth is on fire; wouldn’t that burn off the oxygen? (He asks, literally from a place of complete ignorance…)
Yeah, the problem here is that the question is not sufficiently well defined to answer clearly.
The OP asks about a meteor that “will turn the entire surface into fire for a time period.”
I think that that definition covers both the dinosaur killing one and the one in the video. Clearly, the video example is not survivable by humans or anything other than pretty deep-dwelling ocean or (maybe) cave life. But the dinosaur killing comet arguably meets the OP’s definition and is (maybe? with luck?) survivable by some humans. I mean, birds survived it, and they can’t build nuclear reactor driven submarines, so we’ve got a fighting chance.
The advantage humans have is technology and accumulated knowledge. We’re incredibly adaptable omnivores, which also helps. If the only way to survive is to eat algae and rats we’ll do that. That doesn’t guarantee survival, you can always come up with a hopeless scenario, but it does help.
In theory, you could set up a habit in something like a deep salt mine, then when it’s safe to venture onto the surface again you can jump start farming by actively working at it, rather than just letting the ecosystem regenerate on its own. Of course, there are bajillion variables involved and like I said you can always run into a hopeless situation.
Biosphere 1 is the Earth. It’s not yet a sour rat and cockroach infested hell, though we’re working on it.
Personally, I don’t see what submarines, space stations, etc. have to do with the question. They’re all immensely mass and volume-limited, or in the case of Biosphere 2 there was a goal of a sustainable system. None of that matters here.
Humans are pretty simple to keep alive. We need air, food, and water. We need roughly 1 kg air/day, and probably need about 1 kg of CO2 scrubbing chemicals per day as well. We also need about 1 kg of food/day and maybe 2 kg of water. Let’s round up to 10 kg/day of consumables.
That’s 365 tons of total consumables per person for a century of underground living. That’s nothing! Most stuff is around 1 ton per cubic meter, so a cube just 7 meters on a side is enough to store everything. Sure, we’ll need some space so that the liquid oxygen doesn’t evaporate right away, but that’s all doable.
It would be easy to clear out a mine with plenty of storage for hundreds or thousands of people. No advanced recycling stuff necessary.
You would want some power for lighting and other minor luxuries, which could be provided with a Pu238 radioisotope generator. It has a reasonably long half-life and minimal shielding requirements. You wouldn’t need much; just a few kilowatts would be fine to provide lighting for hundreds of people. The Pu won’t go bad but you could keep a bunch of spare parts around for the other components if necessary.
Heat should not be a problem for a small shelter. The London Underground is getting rather warm lately, having heat-saturated the surrounding rock, but it’s been going for 1.5 centuries and has a huge incoming heat flux. So I don’t think that would be a problem with a relatively small population.
The social problems seem more difficult. The Wool series by Hugh Howey addresses this in a horrific but interesting way. It’s not really that believable in the details (it’s sci-fi, after all), but I did come away convinced that you’d need a pretty nasty-sounding social fabric if you’re to have a remotely stable society in that position.
I think it goes without saying that we should target a ratio of, say, ten females for every male.
Oxygen in the Earth’s atmosphere amounts to around 539 trillion tons (metric). In addition, “… that will turn the entire surface into fire …” may be a little misleading. Bear in mind that combustible material on Earth occupies less than 22% of the surface (by excluding just the oceans and Antarctica, which must be thence reduced significantly for mountains, reg, dunes and other barren areas). Which is to say that the aforementioned “fire” would in large fraction be lavaesque turmoil that consumes much less oxygen than wood, plants, flesh and other biological stuff. The air would get very stinky, but it seems unlikely that it would become fully bereft of oxygen. At least, in the short term – oxygen is noted for its habit of reacting with many things over time.
I wonder if a submarine crew could survive even a much larger comet.
I’m assuming that even a world-burning event like the one in the video would not wipe out sea life. A majority of oxygen production is from the sea. There’s certainly plenty to eat as long as the sun is not so blocked out that the plankton and seaweed dies out.
The sub can make its own water and oxygen, so even if it takes a while for atmospheric oxygen to rebound, they probably have some kind of scuba or other breathing apparatus, so you give the guys who go out to fish supplemental oxygen.
Geothermal heat pump? Along a horizontally bored shaft? Not going to work if the refuge is too deep—see Western Deep Levels and their Brobdingnagian refrigeration needs—but when does ambient underground temperature rise above, say, 72 F?
Depending on the value of larger, of course. I don’t know what survives a Melancholia level event.
(Clearly just an excuse to post that link, which should go directly to 7:02 in the video.)