Surviving an extinction event - meteor strikes

doctoremma

Just for fun, after idly chatting last night about such things....

Do you think humankind would become extinct after a K-T like event? What proportion might survive? Do you think we have the means to survive?

One of the major problems associated with such an event, after all the initial death and destruction, is the dust clouding/loss of sunlight/collapse of food chain. But I reckon that, in terms of food, we can survive without plants, at least in the short term. We can manufacture proteins and other nutrients/vitamins either chemically or via biotech methods. We can grow plants under artificial lights (assuming we have an intact fuel supply). Obviously, we couldn't produce enough to feed the world, but we could produce enough to ensure survival.

Of course, lack of plant life does mean the that proportions of oxygen/carbon dioxide in our atmosphere will change somewhat. How long might it take to become dangerous? How long to recover? Can we pump oxygen into the air via some chemical means?

And without sunlight, it will be cold. But hey, I've got a warm coat...

What other major problems can we overcome that the dinosaurs couldn't? What solutions can you offer?

krd

doctoremma wrote: »

One of the major problems associated with such an event, after all the initial death and destruction, is the dust clouding/loss of sunlight/collapse of food chain.

I don't know why this old canard still clings on. Heavy dust particles cannot stay airborne for long. Most of it would be down in three days at the most. It's the same reason a nuclear winter after a nuclear war is also a myth.

Even very fine dust wouldn't be effective as typical cloud cover - dust flies up from the Sahara to here every so many years. It does zip to the weather.

So, the sky being blocked out for years on end won't be a problem. But, depending on the scale of the asteroid strike, the fallout out would be the real problem. In the first few hours it would fall as highly concentrated acid. This acid rain will be the real problem. It will make any land it falls on infertile for years - rain will eventually wash it out of the top soil, that will take years.

It depends on the size of the ash cloud. It could be small and only really effect the side of the planet it strikes. A big hit, will fill the entire atmosphere with smoke and ash. In that case your chances of survival will be very slim, as a strike of that scale will be accompanied by a burning wind. The heaviest concentration of gas will be near the ground.

But I reckon that, in terms of food, we can survive without plants, at least in the short term. We can manufacture proteins and other nutrients/vitamins either chemically or via biotech methods.

And what are you going to feed the reactors with?

I have thought this out, we might get lucky and have some fungi we can feed on dead trees.

We can grow plants under artificial lights (assuming we have an intact fuel supply).

The only people with an intact electricity supply will be the Icelanders. They have small electricity generators where they literally dig a hole to get free geo-thermal.

Obviously, we couldn't produce enough to feed the world, but we could produce enough to ensure survival.

I wouldn't be that worried. The initial strike will drastically reduce the world's population. So, less people for dinner.

Of course, lack of plant life does mean the that proportions of oxygen/carbon dioxide in our atmosphere will change somewhat.

Most of the carbon dioxide will come down very quickly - and that is a problem for organic life. An overdose of carbonic acid on land and sea. Though it's highly likely, there will be at least microbes who will thrive in this environment. There may be mutant strains of plant life that can survive too, but there probably won't be many.

But I'm not sure. I think clay from volcanic ash is very fertile, but it might take a length of time before the ph is right enough for anything to grow in it.

How long might it take to become dangerous?

Depends on the size of the strike. If large enough, the entire atmosphere will be filled with a choking acrid smoke. And all humans not in a mineshaft will be dead within a few minutes.

But don't think running to a mine shaft will make you safe. Any reasonable size strike will send a shock wave through the earth causing earthquakes everywhere - a mine shaft will not be a safe place to be.

The safest place would be a nuclear powered submarine. Submariners may be the only survivors.

How long to recover?

Depends on what's left.

Can we pump oxygen into the air via some chemical means?

Well, I wouldn't hold my breath waiting to see if it worked. And if it was required, there would be none of us around to do it.

And without sunlight, it will be cold. But hey, I've got a warm coat...

The least of your problems.

What other major problems can we overcome that the dinosaurs couldn't? What solutions can you offer?

There would probably be a few thousand survivors. At least a few submariners. They could survive on scavenging probably for decades. Find warm coats on petrified bodies, that kind of thing.

To find out how long it would take for organic life to recover, you'd have to ask a palaeontologist, or even a geologist. Big extinctions and recovery times would be in the geological record. The Permian-Triassic mass extinction, which wiped out 90 percent of marine and 70 percent of land species, studying the record could tell you a lot about who and what survives.

If 10% of the human population survived, then within a few years the survivors wouldn't be doing too badly. But it would be very unlikely anything like 10% would survive. I believe your chance of survival would be inversely proportional to your size. Even if 1% survived, they'd be fine after a few years.

Or it could just be a few hundred lonely submariners.

doctoremma

Given their prevalence on Hollywood films, would it be possible to dig an "Ark" into the ground, for select people to live and continue the human race?

In those scenarios, what types of power sources are considered? Plants are usually around, presumably being grown under artificial light. Astronaut food?

krd

doctoremma wrote: »

Given their prevalence on Hollywood films, would it be possible to dig an "Ark" into the ground, for select people to live and continue the human race?

During the Cold War, the possibility of an all out nuclear war was more probable than people think.

The Russians were very concerned for the survival of their people. They went to great expense to build an underground city beneath Ekaterinburg - a contributing factor to their eventual bankruptcy. Of course what they meant by their people, was just 20,000 family and friends of the elites. The average Russian was more or less going to be on their own. Still after a nuclear war, there might not be that many Russians left, but they would still be able to have a party.

They installed a nuclear reactor as the city's power source. 1980s Russian nuclear reactors were not the best, to say the least. There was some accident that rendered the underground city completely uninhabitable.

In those scenarios, what types of power sources are considered?

Not a Russian nuclear reactor.

Plants are usually around, presumably being grown under artificial light. Astronaut food?

Fungi based proteins can be grown without light. The simplest is yeast. It can be feed things we can't eat like wood chips, and it'll produce edible yeast in days. It definitely will taste awful, unless you like marmite.

There's something I can't find at the minute, but that's really amazing. An experimental urban farmer outside Detroit. The guy is able to produce tons of Tilpia fish and vegetables in just a few sheds. Feed is fed to the Tilpia, they wee in the water, the water is pumped through a hydroponic bed the plants are in, the plants extract the nutrients, so the whole operation is intensive and wasteless.

This might give you an idea. http://www.cityfarmer.info/category/aquaculture/

We're only a handful of years away from seeing synthetic vat grown meats like beef and chicken. Within about 20 years, it will be unlikely many people will be eating meat that came from real animals.

A cheaper source of power - maybe like nuclear fusion - and agriculture may become something that's done indoors, in urban areas.

I've seen footage of a greenhouse in England, where they use artificial light, and CO2 from a nearby power station. They're able to grow all year round. Plants love CO2.

Capt'n Midnight

The Russian Typhoon class of missile submarine can stay submerged on the seabed for six months and perhaps longer if necessary.

There are plenty of mines at depths of over a kilometre.

Lots of ways of producing SCP (single cell protein) from fuel like natural gas. Only reason it's not done more is that fuel is too expensive.
http://scialert.net/fulltext/?doi=ajft.2011.103.116


A lot of us would die. But the human race would survive.

Of course we are the only species that could actually prevent the impact.

But having space stations, hollowed out asteroids or colonies would be better insurance.

krd

Capt'n Midnight wrote: »

The Russian Typhoon class of missile submarine can stay submerged on the seabed for six months and perhaps longer if necessary.

They can, and occasionally do, stay submerged on the seabed forever.

Of course we are the only species that could actually prevent the impact.

How could we prevent the impact of a large asteroid?

krd

Worst case scenario

Melancholia

https://www.youtube.com/watch?v=fcZWZhUozr4

doctoremma

krd wrote: »

How could we prevent the impact of a large asteroid?

I've read about gravity tugs, solar sails etc. Detonating a nuke near the surface to push it off course.

I've never read about anything that didn't need several years of advance warning and effort. Although the nuke idea is possibly the most immediate in action?

krd

doctoremma wrote: »

I've read about gravity tugs, solar sails etc. Detonating a nuke near the surface to push it off course.

The gravity tug would work, the solar sails too. The solar sails would be an incredible pain the ass to erect. The nuke, would be useless.

I've never read about anything that didn't need several years of advance warning and effort.

Yes, it would take years advance warning. Near Earth Orbit objects are being monitored - not that we can do anything if we realise a major object is headed for us, but we can see them, and computers are powerful enough these days to predict their path. So, we're half way there. That's the near earth orbit.

But.

It was once thought by optimistic scientists, who saw the cosmos through rose coloured glasses, that Jupiter was a big friendly giant, who kept us safe by sweeping the solar system clean of large objects that might destroy our little planet given a chance to collide with us. A friendly big brother. Unfortunately...this was not true.......Jupiter is not the Jolly Orange Giant we thought him to be. No...He is a malevolent monster - using the gravity of his girth to dislodge astral objects from harmless orbits, and possibly sending them careering towards us. ...

The Cosmos was not designed by Walt Disney - There is more of a chance it was designed by the wrathful and insane god of the old testament. "Hey Kids....I gave you a flood ...and I promised I wouldn't do anything like that again.....but, I started drinking again, you made me all angry, like I told you not to...... try a ****** asteroid....see if you can float your boats with your two by twos out of this one.."

An object dislodged by Jupiter could be very hard to see, until we realise it's headed straight for us.

Although the nuke idea is possibly the most immediate in action?

A nuke wouldn't be of much use. A nuke's energy is mostly light. Space is a vacuum - so there is no air to push. Exploding a nuke near an asteroid, might give it a little nudge - it's only going to be light hitting it - an it may be a little hotter for a few days, but that's all it's going to do.

To shatter a large asteroid with a nuke, we'd need to drill a hole in it, and lay a very large nuke.

To give you an idea how big the nuke would need to be, and what we have, from Wikipedia. The Chicxulub impact.

The impactor had an estimated diameter of 10 km (6.2 mi) and delivered an estimated energy equivalent of 100 teratons of TNT (4.2×1023 J).[21] By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba, had a yield of only 50 megatons of TNT (2.1×1017 J),[22] making the Chicxulub impact 2 million times more powerful.



Roughly....To have any chance of shattering a 10km wide asteroid, we'd need a nuke in the teraton range. And we have nothing like that.

It will likely be decades, if not centuries, before we can go from observing objects that may be catastrophic, or disastrous - to being able to do anything about them. As it stands, if we see a big one coming at us, we're doomed. Screwed.

maddragon

We in Ireland will survive as we are already used to surviving for months on end without sunlight.