<p>There is no absolute upper limit to the atmosphere there's only an arbitrary pressure cutoff at 100km up but the atmosphere is effectively unbreathable above six, six-and-a-half kilometers up. The troposphere, where almost everything we care about (like weather) happens, stops at ten kilometers up and contains 70-80% percent of the atmosphere by mass. Total atmospheric weight is 5.1480×10^18 kg plus or minus 1.5×10^15 kg of water vapour.</p>

<p>So all of that is fine but to get a real picture of how the atmosphere relates to the Earth one of my favourite yardsticks is to imagine the Earth is an apple, cut through the apple, the thin line of colour where the skin is? That's a little thicker in proportion than Earth's atmosphere. Hope that helps you with the scale and scope of the thing.</p>

<p>Over geological time the atmosphere can and has changed dramatically, like the <a href="https://simple.wikipedia.org/wiki/Great_Oxygenation_Event" rel="nofollow noreferrer">Great Oxygenation</a> but on a human timescale it's basically stable. However there are certain changes that are almost immeasurably small that make a big difference, just 7 <em>parts per million</em> of <a href="https://en.wikipedia.org/wiki/Ozone_depletion" rel="nofollow noreferrer">ozone depletion</a> is the difference between a working ozone layer and elevated skin cancer rates across the southern hemisphere.</p>

CC BY-SA 3.0
2017-08-14T13:13:49.403Z
@JeopardyTempest Sorry you're quite right I read the Stratosphere+Troposphere number, have edited accordingly. Yeah depends on the source, they don't even agree on the Tropopause limit.
Ash
CC BY-SA 3.0
2017-08-14T13:16:01.583Z
No worries.  Something tells me I'd be the only one to question that (having just looked into it) [because who would know that off the top of their head!?!  Probably too many!]  I thought about limiting to the troposphere, but figured a bigger number was better, and the stratosphere wasn't so unfriendly after all [especially given those nice helpful PPM] :-)
JeopardyTempest
CC BY-SA 3.0
2017-08-14T13:22:29.983Z
@JeopardyTempest Yeah I ball-parked it given a half remembered unit from a 100 level geography paper to start with and only half checked it.
Ash
CC BY-SA 3.0
2017-08-14T19:17:29.857Z
Of course one obvious (if very small in absolute terms) is the change in CO2 concentration from pre-industrial 280 ppm or less to 410 ppm: https://www.scientificamerican.com/article/we-just-breached-the-410-ppm-threshold-for-co2/
jamesqf
CC BY-SA 3.0
2017-08-15T11:54:17.717Z
@jamesqf Yeah I deliberately didn't go there.
Ash
CC BY-SA 3.0
2017-08-14T12:41:00.573Z
2017-08-14T13:12:39.383Z
2017-08-14T13:12:39.383Z
Ash
<p>The mass of the atmosphere is equivalent to about 10 meters of water covering the entire planet.</p>
<p>volume of ocean / earth surface area = 2.6 km</p>
<p>volume of continental crust / earth surface area = 13.7 km</p>

CC BY-SA 4.0
2022-09-14T22:07:18.667Z
2022-09-14T22:15:16.373Z
2022-09-14T22:15:16.373Z
R. Emery
<p>71% of Earth's <strong>surface</strong> is covered with water and 29% land.  </p>

<p>Thinking in that regard, that's saying that on 29% of Earth's "surface" locations you have land below your feet, and in 71% of the locations, you have water.  So to continue in such terms, you'd then ask... ok, what percentage of Earth's surface locations would have air above them!?!  Well that's all of them.  So to if you're comparing it with those percentages, I guess you'd have to say it's another 100%.  Or, if we put them together into a full 3-dimensional surroundings at the surface, well it'd basically be 50% air, 36% water, 14% land.</p>

<p>But to compare how much of each there REALLY is, you need to include depth, getting some sort of 3 dimensional understanding of it.  But the picture that reveals is certainly not the picture we are used to from daily experience.  From the values I was able to find:</p>

<hr>

<p>In terms of the room each takes up, the volume:</p>

<ul>
<li>Surface water (oceans+lakes+rivers, glaciers, etc) is <a href="https://en.wikipedia.org/wiki/Water_distribution_on_Earth" rel="nofollow noreferrer">1.4 billion km³</a></li>
<li>The inside of the Earth is about <a href="https://en.wikipedia.org/wiki/Earth" rel="nofollow noreferrer">1 trillion = 1000 billion km³</a> </li>
<li>For the atmosphere, as mentioned in comments, it's a little more difficult, as the gases only gradually give way to space.  You find less and less gas as you go up, but there's no set spot where there is none, as some tiny amount is always floating off into space.  So where do you draw the line?  A commonly used boundary between the atmosphere and space is the <a href="https://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line" rel="nofollow noreferrer">Karman line</a>.  This would lead to a volume of <a href="https://www.vcalc.com/wiki/vCalc/Sphere+-+Shell+Volume?var-r=6471&amp;var-t=100&amp;var-r-unit=km&amp;var-t-unit=km" rel="nofollow noreferrer">53 billion km³</a> (<a href="https://en.wikipedia.org/wiki/Earth" rel="nofollow noreferrer">using Earth's radius = 6371 km</a>).  Note that only about half of that is in the <a href="https://en.wikipedia.org/wiki/Troposphere" rel="nofollow noreferrer">troposphere</a> and <a href="https://en.wikipedia.org/wiki/Stratosphere" rel="nofollow noreferrer">stratosphere</a>, which are perhaps the familiar zones of the atmosphere where weather and the ozone layer (and 95% of air molecules) reside.</li>
</ul>

<p>To compare these directly, the volume of land is 20+ times larger than the atmosphere (or 40+ times larger than the troposphere+stratosphere), and 750+ times larger than the Earth's water.</p>

<p>Or as percentages, the volume is:</p>

<ul>
<li>Land 95.3%</li>
<li>Air 5.6%,</li>
<li>Ocean 0.1%</li>
</ul>

<hr>

<p>Another useful way to look at is mass.  In terms of how much <a href="https://en.wikipedia.org/wiki/Geosphere" rel="nofollow noreferrer">mass</a> there is of each (<a href="https://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html" rel="nofollow noreferrer">from NASA</a>):</p>

<ul>
<li>Atmosphere: $5.1\times10^{18}$ kg</li>
<li><a href="https://en.wikipedia.org/wiki/Geosphere" rel="nofollow noreferrer">Hydrosphere</a>: $1.4\times10^{21}$ kg</li>
<li><a href="https://en.wikipedia.org/wiki/Geosphere" rel="nofollow noreferrer">Geosphere</a>: $6.0\times10^{24}$ kg</li>
</ul>

<p>So there is 500+ times more water than air... and 4000+ times more "land" than water.</p>

<p>Or in percents, the mass is:</p>

<ul>
<li>Land: 99.98%</li>
<li>Water: 0.02%</li>
<li>Air: 0.00008%</li>
</ul>

<p>You could also look at the comparison in other ways, such as with the number of molecules.  But to save time, the answers will still typically boil down to the same idea: though land is the least of what we <a href="https://www.nasa.gov/multimedia/imagegallery/image_feature_329.html" rel="nofollow noreferrer">see around us on the surface</a> (if you're a true global traveler), it is by far and away the greatest part of our planet overall.</p>

<p>One final visualization that looks interesting is considering if we made giants balls of the air and water at Earth's surface... <a href="http://boingboing.net/2008/03/11/all-the-water-and-ai.html" rel="nofollow noreferrer">they'd actually be about the same size...  and nowhere close to the size of Earth</a> (and that's even neglecting the fact that for fair comparison, the Earth, if somehow all of it could be brought to surface conditions, would be even larger due its current <a href="https://en.wikipedia.org/wiki/Structure_of_the_Earth" rel="nofollow noreferrer">internal compression</a>).</p>

<hr>

<p>As to whether the amount of oxygen is changing, remember no element can be created or destroyed (aside from <a href="https://en.wikipedia.org/wiki/Nuclear_reaction" rel="nofollow noreferrer">nuclear processes</a>).  So the only way oxygen can change is if it is tied up in a <a href="https://en.wikipedia.org/wiki/Nuclear_reaction" rel="nofollow noreferrer">compound</a> or is removed into the ground or space.  In our lifetimes, there is very insignificant change overall, though it sounds like a notable amount is being <a href="http://cdiac.ornl.gov/trends/oxygen/modern_records.html" rel="nofollow noreferrer">used up each day in combustion reactions</a> (see the part about oxygen depletion further down) [oxygen decreases from that, but since carbon dioxide has more mass, the overall atmospheric mass actually increases, just not the stuff you can breathe!].  If you're looking for a much longer history, it appears <a href="https://www.britannica.com/topic/evolution-of-the-atmosphere-1703862" rel="nofollow noreferrer">this Britannica article</a> gives a more thorough discussion of the factors in play and some of the changes that have occurred.</p>

<p>As to the mass of the atmosphere over eons, I naively thought maybe less would be known about that... but articles in <a href="https://www.scientificamerican.com/article/fossil-imprints-of-rain-reveal-early-earth-atmosphere/" rel="nofollow noreferrer">Scientific American</a> and <a href="http://www.nature.com/ngeo/journal/v9/n6/abs/ngeo2713.html?foxtrotcallback=true" rel="nofollow noreferrer">Nature</a> both hint the atmosphere was at much different pressures once upon a time (albeit reaching conclusions in opposite directions!)  Such changes in pressure would likely come with large differences in mass and/or volume of the atmosphere as well, but until someone shows me otherwise, those estimates would seem to be quite speculative.</p>

<p>And if we're going that direction, maybe we should just turn to <a href="https://what-if.xkcd.com/12/" rel="nofollow noreferrer">What-If XKCD</a>!</p>

CC BY-SA 3.0
2017-08-15T08:23:39.733Z
That was great!
Kharak
CC BY-SA 3.0
2017-08-14T08:57:57.180Z
2017-08-14T11:13:36.577Z
2017-08-14T11:13:36.577Z
JeopardyTempest
<p>We know our earth has 71% water and 29% land, but compared to that land and water, how much air do we have in our atmosphere?</p>

<p>I mean: </p>

<ul>
<li>How big is our atmosphere</li>
<li>Is there any increase or decrease in the amount of atmosphere over time</li>
<li>Is there any change in percentage of oxygen over time</li>
</ul>

CC BY-SA 3.0
2017-08-14T05:17:30.973Z
You've given water/land splits for the surface area of the Earth, not really how big it is.  Which, is not really comparable to mass or volume of atmosphere.
f.thorpe
CC BY-SA 3.0
2017-08-14T05:43:00.163Z
You could easily figure this out yourself - with the caveat that the atmosphere doesn't have a sharp upper boundary.  By convention the Karman Line at 100 km/62 miles marks the boundary.  So figure the area of the Earth in km^2, multiply by 100, and you have the volume in km^3.  If you want the weight, atmospheric pressure is just a bit over 10,000 kg/m^2.  The answers to your other questions are yes and yes, but it depends on the time scale you're looking at.
jamesqf
CC BY-SA 3.0
2017-08-15T00:26:39.330Z
@jamesqf In other words, the mass of the atmosphere is equal to a 10 m layer of water.
Keith McClary
CC BY-SA 3.0
2017-08-15T05:37:50.870Z
@Keith McClary: Yes, as you might know if you're a scuba diver.
jamesqf
<atmosphere><geography>
How much atmoshphere is there compared to land and water
Kharak
# How much atmoshphere is there compared to land and water

(Asked by: username_0 on 2017-08-14)

We know our earth has 71% water and 29% land, but compared to that land and water, how much air do we have in our atmosphere?

I mean:

* How big is our atmosphere
* Is there any increase or decrease in the amount of atmosphere over time
* Is there any change in percentage of oxygen over time

**Tags:** atmosphere, geography

> **Comments:**
> **username_1**: You've given water/land splits for the surface area of the Earth, not really how big it is.  Which, is not really comparable to mass or volume of atmosphere.  
> **username_2**: You could easily figure this out yourself - with the caveat that the atmosphere doesn't have a sharp upper boundary.  By convention the Karman Line at 100 km/62 miles marks the boundary.  So figure the area of the Earth in km^2, multiply by 100, and you have the volume in km^3.  If you want the weight, atmospheric pressure is just a bit over 10,000 kg/m^2.  The answers to your other questions are yes and yes, but it depends on the time scale you're looking at.  
> **username_3**: @username_2 In other words, the mass of the atmosphere is equal to a 10 m layer of water.  
> **username_2**: @username_3: Yes, as you might know if you're a scuba diver.  

---

## 3 answers

### Answer by username_5 on 2017-08-14. Score: 5 | Accepted answer

71% of Earth's **surface** is covered with water and 29% land.

Thinking in that regard, that's saying that on 29% of Earth's "surface" locations you have land below your feet, and in 71% of the locations, you have water. So to continue in such terms, you'd then ask... ok, what percentage of Earth's surface locations would have air above them!?! Well that's all of them. So to if you're comparing it with those percentages, I guess you'd have to say it's another 100%. Or, if we put them together into a full 3-dimensional surroundings at the surface, well it'd basically be 50% air, 36% water, 14% land.

But to compare how much of each there REALLY is, you need to include depth, getting some sort of 3 dimensional understanding of it. But the picture that reveals is certainly not the picture we are used to from daily experience. From the values I was able to find:

---

In terms of the room each takes up, the volume:

* Surface water (oceans+lakes+rivers, glaciers, etc) is [1.4 billion km³](https://en.wikipedia.org/wiki/Water_distribution_on_Earth)
* The inside of the Earth is about [1 trillion = 1000 billion km³](https://en.wikipedia.org/wiki/Earth)
* For the atmosphere, as mentioned in comments, it's a little more difficult, as the gases only gradually give way to space. You find less and less gas as you go up, but there's no set spot where there is none, as some tiny amount is always floating off into space. So where do you draw the line? A commonly used boundary between the atmosphere and space is the [Karman line](https://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line). This would lead to a volume of [53 billion km³](https://www.vcalc.com/wiki/vCalc/Sphere+-+Shell+Volume?var-r=6471&var-t=100&var-r-unit=km&var-t-unit=km) ([using Earth's radius = 6371 km](https://en.wikipedia.org/wiki/Earth)). Note that only about half of that is in the [troposphere](https://en.wikipedia.org/wiki/Troposphere) and [stratosphere](https://en.wikipedia.org/wiki/Stratosphere), which are perhaps the familiar zones of the atmosphere where weather and the ozone layer (and 95% of air molecules) reside.

To compare these directly, the volume of land is 20+ times larger than the atmosphere (or 40+ times larger than the troposphere+stratosphere), and 750+ times larger than the Earth's water.

Or as percentages, the volume is:

* Land 95.3%
* Air 5.6%,
* Ocean 0.1%

---

Another useful way to look at is mass. In terms of how much [mass](https://en.wikipedia.org/wiki/Geosphere) there is of each ([from NASA](https://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html)):

* Atmosphere: $5.1\times10^{18}$ kg
* [Hydrosphere](https://en.wikipedia.org/wiki/Geosphere): $1.4\times10^{21}$ kg
* [Geosphere](https://en.wikipedia.org/wiki/Geosphere): $6.0\times10^{24}$ kg

So there is 500+ times more water than air... and 4000+ times more "land" than water.

Or in percents, the mass is:

* Land: 99.98%
* Water: 0.02%
* Air: 0.00008%

You could also look at the comparison in other ways, such as with the number of molecules. But to save time, the answers will still typically boil down to the same idea: though land is the least of what we [see around us on the surface](https://www.nasa.gov/multimedia/imagegallery/image_feature_329.html) (if you're a true global traveler), it is by far and away the greatest part of our planet overall.

One final visualization that looks interesting is considering if we made giants balls of the air and water at Earth's surface... [they'd actually be about the same size... and nowhere close to the size of Earth](http://boingboing.net/2008/03/11/all-the-water-and-ai.html) (and that's even neglecting the fact that for fair comparison, the Earth, if somehow all of it could be brought to surface conditions, would be even larger due its current [internal compression](https://en.wikipedia.org/wiki/Structure_of_the_Earth)).

---

As to whether the amount of oxygen is changing, remember no element can be created or destroyed (aside from [nuclear processes](https://en.wikipedia.org/wiki/Nuclear_reaction)). So the only way oxygen can change is if it is tied up in a [compound](https://en.wikipedia.org/wiki/Nuclear_reaction) or is removed into the ground or space. In our lifetimes, there is very insignificant change overall, though it sounds like a notable amount is being [used up each day in combustion reactions](http://cdiac.ornl.gov/trends/oxygen/modern_records.html) (see the part about oxygen depletion further down) [oxygen decreases from that, but since carbon dioxide has more mass, the overall atmospheric mass actually increases, just not the stuff you can breathe!]. If you're looking for a much longer history, it appears [this Britannica article](https://www.britannica.com/topic/evolution-of-the-atmosphere-1703862) gives a more thorough discussion of the factors in play and some of the changes that have occurred.

As to the mass of the atmosphere over eons, I naively thought maybe less would be known about that... but articles in [Scientific American](https://www.scientificamerican.com/article/fossil-imprints-of-rain-reveal-early-earth-atmosphere/) and [Nature](http://www.nature.com/ngeo/journal/v9/n6/abs/ngeo2713.html?foxtrotcallback=true) both hint the atmosphere was at much different pressures once upon a time (albeit reaching conclusions in opposite directions!) Such changes in pressure would likely come with large differences in mass and/or volume of the atmosphere as well, but until someone shows me otherwise, those estimates would seem to be quite speculative.

And if we're going that direction, maybe we should just turn to [What-If XKCD](https://what-if.xkcd.com/12/)!

> **Comments:**
> **username_0**: That was great!  

---

### Answer by username_4 on 2017-08-14. Score: 2

There is no absolute upper limit to the atmosphere there's only an arbitrary pressure cutoff at 100km up but the atmosphere is effectively unbreathable above six, six-and-a-half kilometers up. The troposphere, where almost everything we care about (like weather) happens, stops at ten kilometers up and contains 70-80% percent of the atmosphere by mass. Total atmospheric weight is 5.1480×10^18 kg plus or minus 1.5×10^15 kg of water vapour.

So all of that is fine but to get a real picture of how the atmosphere relates to the Earth one of my favourite yardsticks is to imagine the Earth is an apple, cut through the apple, the thin line of colour where the skin is? That's a little thicker in proportion than Earth's atmosphere. Hope that helps you with the scale and scope of the thing.

Over geological time the atmosphere can and has changed dramatically, like the [Great Oxygenation](https://simple.wikipedia.org/wiki/Great_Oxygenation_Event) but on a human timescale it's basically stable. However there are certain changes that are almost immeasurably small that make a big difference, just 7 *parts per million* of [ozone depletion](https://en.wikipedia.org/wiki/Ozone_depletion) is the difference between a working ozone layer and elevated skin cancer rates across the southern hemisphere.

> **Comments:**
> **username_4**: @username_5 Sorry you're quite right I read the Stratosphere+Troposphere number, have edited accordingly. Yeah depends on the source, they don't even agree on the Tropopause limit.  
> **username_5**: No worries.  Something tells me I'd be the only one to question that (having just looked into it) [because who would know that off the top of their head!?!  Probably too many!]  I thought about limiting to the troposphere, but figured a bigger number was better, and the stratosphere wasn't so unfriendly after all [especially given those nice helpful PPM] :-)  
> **username_4**: @username_5 Yeah I ball-parked it given a half remembered unit from a 100 level geography paper to start with and only half checked it.  
> **username_2**: Of course one obvious (if very small in absolute terms) is the change in CO2 concentration from pre-industrial 280 ppm or less to 410 ppm: https://www.scientificamerican.com/article/we-just-breached-the-410-ppm-threshold-for-co2/  
> **username_4**: @username_2 Yeah I deliberately didn't go there.  

---

### Answer by username_6 on 2022-09-14. Score: 0

The mass of the atmosphere is equivalent to about 10 meters of water covering the entire planet.

volume of ocean / earth surface area = 2.6 km

volume of continental crust / earth surface area = 13.7 km


---

