Which will cause the collapse of civilization as we know it?

Question

While global warming is getting much of the news, I was wondering if the real disaster manking is facing is realy oxygen depletion?
When I went to grade school I was taught that air was 20% O2, then in college it was 18%, now I have heard 16%. If these are true and if humans pass out at levels under 14% it would seem we don't have as long to correct our CO2 emissions before civilization will fall.
So what do you think will cause civilizations fall, global warming, O2 depletion, some other man made disaster or some natural disaster?

Answer 1

Oxygen concentration has not fallen. If you heard 18% or lower, you were misinformed. Earth's atmosphere contains roughly (by molar content/volume) 78% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, trace amounts of other gases, and a variable amount (average around 1%) of water vapor. These numbers have not changed in countless centuries. Except carbon dioxide has gone up from about 0.028% to the present value becasue of all the coal and oil burning. It is possible that the 0.01% increase in carbon dioxide has been accompanied by a 0.01% decrease in oxygen, but if it has I never heard about it. But if it did, then the "old" concentration of oxygen would have been 20.96%.

Bottom line, the present concentration of oxygem is, rounded to the nearest whole percent, 21%.

Answer 2

Nuclear War is by far the most likely danger. There has been many instances where nuclear war was a reasonably likely scenario, for example when USA dropped 2 Nukes on Japan in WW2. If the US was wrong about their intelligence on Japan, Japan would have retaliated most likely. The cold war went for 40 years and the nuclear threat was huge ( I belive Kissinger who was secretary of state in the 60's said the chance was 1 in 2!). George W Bush has been reigniting the idea that the US can win a Nuclear War by Having a Laser Shield to shoot down a any Nuclear retaliation from a US first Strike. The Iraq war is still simmering, and Iran and other turbulent nations are increasing there interest in nuclear weapons. In 50 years there will probably be 50 states with nuclear warhead launch capibilitys.

Humans have already dropped Nukes on each other its only a matter of time and curcumstances untill the next one is dropped, and it'll be much much worse as one nuke these days is about 15 Megatonnes of blast ( 30 times larger that the WW2 Nukes), one of these could destroy all of australia, and there are thousands of Nukes stockpiled. The Geopolitical environment is deteriorating, increasing the chance of wider war,which increases the chance a Nuke will be used.

Answer 3

Corruption and apathy of the leaders Outrage of the individuals grants of a greater useful international crumbling infrastructure uneducated infants countless wars that do not something to income the rustic they serve extensive bills that cannot be repaid no jobs A fallen center classification best a desperate decrease classification this mixture is what collapsed Rome and distinctive different as quickly as great worldwide places, Prussia, Russia (the two Czarist and Communist) Egypt, France and distinctive others.

Answer 4

What the global oxygen level is now, I don't know. I can comment on the 20% level that you heard about in early school. The level given was a rounded amount for simplicity. The actual amount is a little less than that because of the other gases in the atmosphere besides Nitrogen.
All that you have named, plus war will be the causes of the downfall of civilization. Our greed, and power lust is our down fall.

Answer 5

To answer this question, we all know about the dozen or so doomsday scenarios: asteriods and the like hitting the earth, gamma rays, mega volcano, mega tsunami, mega hurricanes, mega earthquakes, mega anti social behavior on a global scale, mega fires, mega famine, mega apathy, nuclear war, climate gone wild, drug resistant virus, super virus, megalomaniacs, and scientists toying with physics in order to create an endless source of energy but instead creating a black hole that swallows earth whole. Perhaps a combination of the aforementioned.

Answer 6

OK think for a minute. If we cut down the amount of CO2 in the air, plants won't grow as well, because they depend on it for growth. Plants manufacture oxygen. You're barking up the wrong tree my friend. If you will check your resources you will find that the rise in co2 isn't the cause of warming, it's the result of it. It follows warming cycles by hundreds of years. Ah what's the use? Our country has turned into a herd of sheep. The end of civilization as we know it? Apathy will be the culprit, and the failure to reason and think for ourselves.

Answer 7

It's not that we'll ever run out of oxygen or "air". We're just displacing it with more and more toxins each day which is causing all kinds of illnesses.

Man will fall either by war or poisoning of our own planet. Nature will have nothing to do with it.

Answer 8

Global warming will be the collapse of civilization as we know it. People need to start going green.

Answer 9

No I'm thinking it will be an all out war. Either religion or race and it will get very ugly very fast but will have a slow death. But once lines are crossed there will be no turning back, the wheels will be set in motion and death for all will be eminent.

Answer 10

There many variables. Global warming is one. An impact from a comet or asteroid is another. But our greatest concern is ourselves. Who will "push the button" on a necular weapon 1st?