<p>I would dispute the idea that the "vast majority" of the world's buildings have air con; in fact, considering that a large proportion of the world's buildings are either (a) in hitherto cool places; or (b) in undeveloped places, I would imagine that it's probably a minority. But I don't have figures on this.</p>

<p>The main part of the question, though, is about the proportion of the earth's surface that is built on. That could be approached as a GIS exercise, and would be reasonably easy to do in places like the UK that have freely-available maps that show all buildings... and very much harder to do in parts of the world that don't.</p>

<p><a href="http://sedac.ciesin.columbia.edu/data/set/grump-v1-urban-extents" rel="nofollow noreferrer">This study</a> made an estimate (from various data sources, including nighttime lighting) that about 3% of the Earth's land area is "urban". That certainly doesn't include all buildings, but it also includes urban spaces that are not buildings, so it may serve as a useful first approximation.</p>

<p>Depending on your objective, you might find it more useful to stop thinking specifically about air conditioning and instead ask about heat produced by buildings. All buildings produce heat, whether this is from heating, cooling, or other energy use. As a proxy for this net heat production you could simply look at the buildings' energy consumption.</p>

CC BY-SA 4.0
2018-08-16T09:02:30.397Z
2018-08-16T09:02:30.397Z
Semidiurnal Simon
<p>EDIT: My goal with this question was to better understand the impact of cooling systems on local urban environments, but its been pointed out I am asking the incorrect questions for the answer's Im looking for. So this can be disregarded, but I'm not deleting as deleting questions seems to be frowned upon.</p>

<p>I am exploring some ideas regarding the impact of urbanization on the climate and our environment. My basic thought process is that the vast majority of homes and work places have some form of air conditioning(I understand many parts of the world dont, but from estimates I saw the global average is still quite high). And as I understand it air conditioning functions to displace heat(and slight heat generation from the energy usage). Like putting a brick in a bucket causes the water level to rise so too does the outside heat level rise when the heat from inside buildings is displaced.</p>

<p>What I am looking to find out is if there is a way to determine what percentage of the planet's land surface is covered by buildings occupied by humans to determine what percentage of the world is displacing heat from the inside of those buildings(and the area that space occupies) to outside(all the other area)</p>

<p>I understand not every building has air conditioning and will not being using that figure to make a determination(as my previous post had people suggesting). I am simply looking for a good place to start before adding control variables. </p>

<p>Does anyone have any resources to find out where one might come by these figures? </p>

<p>Additionally if someone has a possibly better method to find out the information I'm looking for I would love suggestions.</p>

CC BY-SA 4.0
2018-08-15T18:13:41.853Z
The only contribution of heat from air conditioning is related to their energy consumption. The rest is just redistribution of heat, that have no long term impact at all. If you want to estimate how much heat human housing adds to the Earth system, the best approach would be to calculate how much energy households consume worldwide. Because the vast majority of all the energy we use end up as heat sooner or later (the exception would be the small a mount of light that escape to space, mostly from public illumination in cities).
Camilo Rada
CC BY-SA 4.0
2018-08-15T19:44:53.953Z
I understand that heat isn't being "created" besides the energy usage, but can you clarify why you consider that it would not have a long term impact if the redistribution takes place consistently?

Using the analogy before, lets say you were concerned about how high the water level was(or heat levels), if you put the brick in the bucket it would raise the water level until the brick was removed. One could say "the brick has no impact on the amount of water", but it DOES have an impact on the level of water(which is the concern). Doesn't that matter?
Dthorpe
CC BY-SA 4.0
2018-08-15T20:23:36.940Z
Using your analogy, air conditioning is like using your hands to push the water to one side of the bucket. As long as you keep moving your hands, the water level will be higher in one side of the bucket than the other (i.e. cooler  inside and hotter outside). But as soon as you stop moving your hands, the level will go back to equilibrium.
In the air conditioning case. As soon as the temperature outside goes down, and people turn off air conditioning. The inside will go back to thermal equilibrium with the outside. Erasing any effect on the heat redistribution (i.e. no long term effect)
Camilo Rada
CC BY-SA 4.0
2018-08-15T20:31:08.247Z
Again, the largest effect by far is the amount of energy used by air conditioning to keep the thermal imbalance. If you just focus on energy consumption you will get a much better idea of the heat contribution of housing to the Earth system.
That will also include the many places that are heated, and on the long run all that heat finally escapes to the outside of the buildings.
Camilo Rada
CC BY-SA 4.0
2018-08-15T20:36:58.393Z
I agree mostly, but again what im concerned about is the level of heat, not the overall amount of heat in the atmosphere, I dont think a large field being 5 degrees hotter is a big deal, but if say, during the peak hours of heat it was 10 degrees hotter than it would be otherwise, isnt that worth measuring? Yes once things "equalize" it goes back to normal, but while its not equalized isnt the increased level something worth examining?
Dthorpe
CC BY-SA 4.0
2018-08-15T20:39:53.820Z
Let me clarify, Lets say you have someone in a pool, the water normally goes up to their chest, now you displace a large part of the water. No water is being created, and the person isnt in danger until the level of water is above their mouth/nose. Now imagine you only displace water for half the day. During half the day the displacement makes the water go above their head.They will die and then later when the water level equalizes they will still be dead. I understand no water was created, but the effect the water had during one moment cant necessarily be equalized later.Does that make sense?
Dthorpe
CC BY-SA 4.0
2018-08-15T21:14:44.043Z
Fair enough. If you are worried about local effects that makes sense. However, your request for global data suggested you were considering the global effect of pulling heat out of buildings.
If you want to consider the local effects, you have to start by testing that hypothesis: Do air conditioning significantly increase the outside temperature? How much? How far?
You will have to consider factors like wind and vertical mixing of the air. My guess is that the effect will be negligible, except within dense cities with many air conditioning, no wind and little vertical mixing
Camilo Rada
CC BY-SA 4.0
2018-08-15T21:18:08.097Z
You're right I should have started there. I appreciate the help in coming to that conclusion. Thank you for your patience in me doing my best to get my thought process across.
Dthorpe
CC BY-SA 4.0
2018-08-16T15:26:48.987Z
Well, then with all that input, please [edit] you question to make much clearer what you attempt to do. Ideally, after that, all comments here should be superfluous.
Jan Doggen
CC BY-SA 4.0
2018-08-19T00:48:08.437Z
One thing worth noting: the byproduct is indeed heat. Thing is... air that is warmer than its surroundings rises. So though it'd seem reasonable to simply say that, for example, 50% of a city is A/C'ed 20°F cooler than the surroundings... so the remaining 50% would be 20(+)°F warmer, it's not. That warmth is mixed into many 100s of meters of afternoon atmosphere. Really I'd think it'd have more impact on the depth of atmosphere mixed. Theoretically that could mean earlier daytime storm initiation or other impacts on precip/clouds/etc. Now is it a major factor vs concrete's urban heat effect???
JeopardyTempest
CC BY-SA 4.0
2018-08-19T00:53:08.173Z
And to finish the idea, therefore winter heating might actually offer the potential for a more notable temperature impact. The cool air released from central heaters would theoretically sink and cool daytime temperatures in frigid cities. However, the electrical energy... any heat island/other energy discharges... plus the fact much of cities are heated by more direct means (i.e. combustion like natural gas used to head water in a radiator system) that'd only add heat... means I'd think its impacts locally probably also end up being small.  But interesting question to think about, definitely!
JeopardyTempest
<climate><data-analysis>
Are there resources for determining what percentage of the earth's surface is occupied by air conditioned spaces?
Dthorpe
# Are there resources for determining what percentage of the earth's surface is occupied by air conditioned spaces?

(Asked by: username_0 on 2018-08-15)

EDIT: My goal with this question was to better understand the impact of cooling systems on local urban environments, but its been pointed out I am asking the incorrect questions for the answer's Im looking for. So this can be disregarded, but I'm not deleting as deleting questions seems to be frowned upon.

I am exploring some ideas regarding the impact of urbanization on the climate and our environment. My basic thought process is that the vast majority of homes and work places have some form of air conditioning(I understand many parts of the world dont, but from estimates I saw the global average is still quite high). And as I understand it air conditioning functions to displace heat(and slight heat generation from the energy usage). Like putting a brick in a bucket causes the water level to rise so too does the outside heat level rise when the heat from inside buildings is displaced.

What I am looking to find out is if there is a way to determine what percentage of the planet's land surface is covered by buildings occupied by humans to determine what percentage of the world is displacing heat from the inside of those buildings(and the area that space occupies) to outside(all the other area)

I understand not every building has air conditioning and will not being using that figure to make a determination(as my previous post had people suggesting). I am simply looking for a good place to start before adding control variables.

Does anyone have any resources to find out where one might come by these figures?

Additionally if someone has a possibly better method to find out the information I'm looking for I would love suggestions.

**Tags:** climate, data-analysis

> **Comments:**
> **username_1**: The only contribution of heat from air conditioning is related to their energy consumption. The rest is just redistribution of heat, that have no long term impact at all. If you want to estimate how much heat human housing adds to the Earth system, the best approach would be to calculate how much energy households consume worldwide. Because the vast majority of all the energy we use end up as heat sooner or later (the exception would be the small a mount of light that escape to space, mostly from public illumination in cities).  
> **username_0**: I understand that heat isn't being "created" besides the energy usage, but can you clarify why you consider that it would not have a long term impact if the redistribution takes place consistently?  Using the analogy before, lets say you were concerned about how high the water level was(or heat levels), if you put the brick in the bucket it would raise the water level until the brick was removed. One could say "the brick has no impact on the amount of water", but it DOES have an impact on the level of water(which is the concern). Doesn't that matter?  
> **username_1**: Using your analogy, air conditioning is like using your hands to push the water to one side of the bucket. As long as you keep moving your hands, the water level will be higher in one side of the bucket than the other (i.e. cooler  inside and hotter outside). But as soon as you stop moving your hands, the level will go back to equilibrium. In the air conditioning case. As soon as the temperature outside goes down, and people turn off air conditioning. The inside will go back to thermal equilibrium with the outside. Erasing any effect on the heat redistribution (i.e. no long term effect)  
> **username_1**: Again, the largest effect by far is the amount of energy used by air conditioning to keep the thermal imbalance. If you just focus on energy consumption you will get a much better idea of the heat contribution of housing to the Earth system. That will also include the many places that are heated, and on the long run all that heat finally escapes to the outside of the buildings.  
> **username_0**: I agree mostly, but again what im concerned about is the level of heat, not the overall amount of heat in the atmosphere, I dont think a large field being 5 degrees hotter is a big deal, but if say, during the peak hours of heat it was 10 degrees hotter than it would be otherwise, isnt that worth measuring? Yes once things "equalize" it goes back to normal, but while its not equalized isnt the increased level something worth examining?  
> **username_0**: Let me clarify, Lets say you have someone in a pool, the water normally goes up to their chest, now you displace a large part of the water. No water is being created, and the person isnt in danger until the level of water is above their mouth/nose. Now imagine you only displace water for half the day. During half the day the displacement makes the water go above their head.They will die and then later when the water level equalizes they will still be dead. I understand no water was created, but the effect the water had during one moment cant necessarily be equalized later.Does that make sense?  
> **username_1**: Fair enough. If you are worried about local effects that makes sense. However, your request for global data suggested you were considering the global effect of pulling heat out of buildings. If you want to consider the local effects, you have to start by testing that hypothesis: Do air conditioning significantly increase the outside temperature? How much? How far? You will have to consider factors like wind and vertical mixing of the air. My guess is that the effect will be negligible, except within dense cities with many air conditioning, no wind and little vertical mixing  
> **username_0**: You're right I should have started there. I appreciate the help in coming to that conclusion. Thank you for your patience in me doing my best to get my thought process across.  
> **username_2**: Well, then with all that input, please [edit] you question to make much clearer what you attempt to do. Ideally, after that, all comments here should be superfluous.  
> **username_3**: One thing worth noting: the byproduct is indeed heat. Thing is... air that is warmer than its surroundings rises. So though it'd seem reasonable to simply say that, for example, 50% of a city is A/C'ed 20°F cooler than the surroundings... so the remaining 50% would be 20(+)°F warmer, it's not. That warmth is mixed into many 100s of meters of afternoon atmosphere. Really I'd think it'd have more impact on the depth of atmosphere mixed. Theoretically that could mean earlier daytime storm initiation or other impacts on precip/clouds/etc. Now is it a major factor vs concrete's urban heat effect???  
> **username_3**: And to finish the idea, therefore winter heating might actually offer the potential for a more notable temperature impact. The cool air released from central heaters would theoretically sink and cool daytime temperatures in frigid cities. However, the electrical energy... any heat island/other energy discharges... plus the fact much of cities are heated by more direct means (i.e. combustion like natural gas used to head water in a radiator system) that'd only add heat... means I'd think its impacts locally probably also end up being small.  But interesting question to think about, definitely!  

---

## 1 answers

### Answer by username_4 on 2018-08-16. Score: 2

I would dispute the idea that the "vast majority" of the world's buildings have air con; in fact, considering that a large proportion of the world's buildings are either (a) in hitherto cool places; or (b) in undeveloped places, I would imagine that it's probably a minority. But I don't have figures on this.

The main part of the question, though, is about the proportion of the earth's surface that is built on. That could be approached as a GIS exercise, and would be reasonably easy to do in places like the UK that have freely-available maps that show all buildings... and very much harder to do in parts of the world that don't.

[This study](http://sedac.ciesin.columbia.edu/data/set/grump-v1-urban-extents) made an estimate (from various data sources, including nighttime lighting) that about 3% of the Earth's land area is "urban". That certainly doesn't include all buildings, but it also includes urban spaces that are not buildings, so it may serve as a useful first approximation.

Depending on your objective, you might find it more useful to stop thinking specifically about air conditioning and instead ask about heat produced by buildings. All buildings produce heat, whether this is from heating, cooling, or other energy use. As a proxy for this net heat production you could simply look at the buildings' energy consumption.


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