# What would happen if oxygen were to briefly disappear from Earth's atmosphere, then reappear?

Imagine that the oxygen disappears from earth's atmosphere for some 10 seconds completely. what would be the casualties it would cause, what would be the climatic changes and other changes it would bring upon.

• I believe casualties would be 100%, as long as I remember everyone that i know need to breath constantly... – Jorge Aldo Mar 31 '15 at 5:39
• @Akshay Vasu do you mean oxygen as in gas completely vented from earth or as in atoms? Without O2, close to 99% of all lifeforms will eventually die off removing all O atoms Earth is no longer unique, life as we know ceased to exist. – user6760 Mar 31 '15 at 5:53
• @user6760 yes completely without oxygen just for few seconds – Akshay Vasu Mar 31 '15 at 7:59
• Thanks for the accept, generally it's a good idea to wait for a day or two to see if better answers come along but if my answer is good enough for you then that's fine :) – Tim B Mar 31 '15 at 8:47
• Sounds like a good question for What-If XKCD :) – user4239 Mar 31 '15 at 19:12

Well, do you mean all oxygen everywhere or just free oxygen in the air?

If it's all oxygen everywhere then everyone dies, the end.

If it's just the free oxygen in the air then not much will change.

All fires would go out. They may re-ignite once the oxygen returns.

Most people wouldn't even pass out, although they may feel a bit light headed or dizzy. Someone who was already swimming or holding their breath or struggling to breathe already might be badly effected.

The longer you extend the period without oxygen though the more drastic the consequences would be and the more and more people would be affected.

• Sketchy second-hand anecdote but in a lab environment, where there have been nitrogen leaks (effectively reducing the oxygen concentration to below survivable levels) people have apparently collapsed in a few seconds, prompting others who see this from outside to rush in to help and also collapse almost instantly resulting in groups of fatalities. May be they would have all recovered had the room vented quickly (say in 10 seconds) AND this story may have been tweaked in the interest of lab safety, but 10 seconds may at least floor anyone who was walking about unaware. – Brent Hackers Sep 19 '17 at 9:54

Assuming you mean every single oxygen atom in every single molecule:

• Water would all evaporate. Because water contains oxygen and hydrogen (H2O), and the oxygen is gone, it is now only hydrogen. And with 326 million trillion gallons of water on earth, that's alot of hyrdrogen in the atmosphere.
• Nuclear power plants now have no cooling water, so a very big chain reaction of unstoppable nuclear explosions. There are 434 nuclear power plants, so alot of deaths would be caused.
• The ozone is made of a different molecule of oxygen. (The ozone is O3, and the oxygen in air is O2). Without it, everybody will get severe sunburn, plants will dye, and meteorites will hit earth(as the ozone protects the earth from many minor meteorites every day).
• All DNA is 30% oxygen. The basic building blocks of life are gone. No living thing is alive anymore.

So basically, in less than 10 seconds without oxygen, every living thing is dead, loads of stuff has exploded, and there is no water anymore (even if the oxygen does come back after 10 seconds, the hydrogen is now floating, requiring a massive chemical reaction to make it back to water, and then it would seemingly fall out of the sky.).

Sources:

Wonderpedia Magazine, Issue 19, Dec 2013

High School Science class

• "Without [ozone] ... meteorites will hit earth."[citation needed] How does ozone (or even oxygen in general) disappearing from the atmosphere for a few seconds cause meteorites to hit Earth? – a CVn Apr 5 '15 at 14:26
• I believe this is the correct answer, as it stands now. – Jorge Aldo Apr 5 '15 at 14:38
• @Michael Kjorling Incredibly sorry for the very late reply, I have been busy and inactive on this site for a while. I believe that many minor meteorites burn up in the ozone every day, so by removing the ozone, most of them would make it to earth and hit us. (I use the term meteorites to refer to asteroids, meteorites and meteors colloquially). – PlanetalFlame Sep 21 '15 at 19:55
• @PlanetalFlame They burn up due to friction heating when passing through the atmosphere. $O_3(g)$ makes up a tiny fraction of the atmosphere. – a CVn Sep 21 '15 at 20:34

If the bee disappears from the surface of the earth, man would have no more than four years to live - Einstein

We will start with that. If oxygen goes out for like a few seconds, many living organisms will disappear from the face of the earth. I am talking about many micro organisms which too play an important role in the whole eco system thing. Food chain might crumble (or maybe not depending on the duration of the time the oxygen chooses to disappear). A lot of marine species will die (if the oxygen in the water bodies disappear too) People may not die as an immediate effect. But it might change the world as we know it. It might speed up many impending undesirable effects. A few flights will crash for sure. A lot or car accidents, bike accidents and such stuffs would be rampant.

• Do you have an example of living organism that die in only 10 second without oxygen ? 10 second is quite short ! – Tyrabel Aug 30 '15 at 18:44
• I'm puzzled, this answer is completely pointless as long as it doesn't give any specific example… – o0'. Aug 30 '15 at 23:33

assuming you mean free oxygen in the air:

Humans can not breath for 3 minutes before losing consciousness (with excpetions such as peple with asthma, other medical conditions, etc). So no one would die of asphyxiation.

The drop in atmospheric pressure probably wouldn't be fatal, but may cause burst capppiliries. Landing/taking off aircraft may hit the runway.

on the bright side, fires would go out. On the not-so-bright side, anything burning gas (cookers, etc) would produce some carbon monoxide.

I reckon it would be a memorable event, but everything would back to normal in a day.

1. All eardrums would explode.
2. All water would bleed into space.
3. All concrete would turn into dust.
4. All combustion engines would fail.
5. All living things would die.