6 ms·

The World's 2.75B Buildings

148 points by marklit 1y ago

chasing0entropy 1y ago
AI is responsible for 60% of all internet traffic this morning, OP is the other 40%. But on a serious note this is an interesting project highlighting the sheer volume of power usage across the world. .. I'm also curious given the data and power usage, if AI assisted heatmap is actually more accurate than one developed by downloading a single dataset of high resolution satellite imagery at night, performing algorithmic analysis to draw heatmap based on light output or !maybe even simple image processing downsampling the image and shifting white-blue to red?
- marklit 1y ago
  70% of daytime RGB sat imagery is covered by clouds. I'm not sure how easy it would be to spot if clouds were covering a city's lights at night. I've only seen Maxar publish one night time image and that was of Dubai. I suspect smaller buildings in not so well lit areas could end up getting missed out. SAR imagery would work well for seeing at night and through clouds but I'm not sure what the state of AI building footprint detection is with SAR atm.
  - chasing0entropy 1y ago
    Fascinating. So no such satellite data exists. Thanks for the insight, makes the linked write up much more satisfying.
Qem 1y ago
> The United Nations (UN) believes there are 4B buildings on Earth. This week, a dataset called "GlobalBuildingAtlas" (GBA) was published by researchers at the Technical University of Munich (TUM) that attempts to estimate this number at being closer to 2.75B. If we painted the roofs on all of them white, by how much would the temperature of the planet drop?
- csmoak 1y ago
  there is a cool project that explores this topic: https://coolcolors.lbl.gov/ https://coolcolors.lbl.gov/
- jl6 1y ago
  Probably not as much as if we “painted” them black with solar panels and used the resulting electricity to displace fossil fuel burning.
  - marklit 1y ago
    A good percentage of Pakistan did this recently and removed 35% of demand off of their grid https://www.ted.com/talks/jenny_chase_solar_energy_is_even_cheaper_than_you_think/transcript https://www.ted.com/talks/jenny_chase_solar_energy_is_even_c...
    - mcny 1y ago
      I would love to have an air conditioning / cooling solution that is directly linked to solar panels with no batteries involved. Like the sun shines, we get electricity, we do the work. My main goal for this thought experiment is to come up with uses of solar electricity that is resilient to the unpredictable and unreliable energy generation from solar. Thoughts?
      - bragr 1y ago
        Though experiment? This is already a thing in the off grid community. In practice you need at least small battery to smooth out the power, but it doesn't take much home automation to kick on the mini split when the panels/inverters have power to spare.
      - Qem 1y ago
        > I would love to have an air conditioning / cooling solution that is directly linked to solar panels with no batteries involved. I think that would be very viable with fridges, that represent a large share of electricity consumption among the poorest. Before electricity, people powered fridges by constantly buying ice blocks. They were just isolated boxes where food was stored together with the blocks. Perhaps it's just necessary to go back at the roots, and make fridges that take energy from solar panels and generate a lot of ice by day, and uses it to keep cold at night, with no need for batteries.
jtwaleson 1y ago
Ok a bit off topic but isn't a 1200W PSU overkill for this system? For a 9950X and 1080, 500W seems plenty.
- nixass 1y ago
  I see it says Corsair so cannot tell what exact model it is but I did relatively similar thing. Reason being if you keep the load under certain wattage the PSU will run in passive cooling mode. My rig will never reach 50% of what Corsair SF750 Platinum can deliver and not mention in normal light load circumstances. It spins up its fans only when the load reaches ~300W or so. Some people are very anal about any kind of noise coming out of their rigs. I personally undervolt everything to keep the fans at bay/minimum and having extra legroom in PSU department helps a lot
  - zamadatix 1y ago
    Same. Part of the background info on this is PSUs are usually most efficient at (or just under) 50% load. They are also more efficient at 240 V than 120 V, if you have the circuit. So the real efficiency can end up varying significantly, depending how you use it. The efficiency is not usually much to write home about in terms of your electric bill, but it does help drive the ability for the PSU to cool itself passively.
- marklit 1y ago
  I'm hoping to use most of this system for the next 10 years. At some point, I want to add some beefy GPUs to it when I get back into 3D again.
jongjong 1y ago
Kind of crazy to think that there are almost half as many buildings as people and yet me and my wife can't even afford the deposit to buy a single one on a mortgage after 10 years of saving, hustling hard, taught myself to code, got a university degree, worked in the tech sector, near the forefront of all the hot tech tends... Meanwhile, all this time, I'm told I'm privileged. I must be the victim of some kind of massive PsyOp conspiracy.
- dyauspitr 1y ago
  You can buy a small house in rural America for $25,000
  - trallnag 1y ago
    Rural Russia as well. But you will probably have to get your water from a well and poop into a latrine.
    - deleted 1y ago
      [deleted]
  - jongjong 1y ago
    In my country (Australia), the cheapest I can get is like $250k USD equivalent... But that's a shack in the middle of the desert in some tiny ghost town. Even in a normal small town, houses are like $350k USD minimum. In capital cities, it's like $500k USD minimum for a tiny apartment... Top salaries for top senior software devs are like $130k USD before tax, taxed at about 40%... So take home pay is like $78k USD net income. Rent is like $22k per year minimum. Impossible to get fixed-rate mortgages; banks only only do variable rate... 20% minimum deposit. This is in a country with a LOT of spare land which is scarcely populated.
    - RobGR 1y ago
      Your country exports timber to China and has a lot of empty land. Who benefits from this situation ?
Gys 1y ago
Is it possible to calculate from that data the total surface area of all roofs? I think there is paint that converts solar energy into radiation that goes straight back into space. I wonder if using that paint on a significant percentage of buildings would matter.
- Llamamoe 1y ago
  Are you perhaps thinking of radiative cooling, e.g. paint that reflects close to 100% of all light, excluding the spectrum at which room-temperature objects radiate heat, resulting in a net cooling effect? E.g. [Revolutionary Paint: How to Make Surfaces Stay Cool in the Sun](https://youtu.be/dNs_kNilSjk https://youtu.be/dNs_kNilSjk)
  - Gys 1y ago
    Thanks for the video! Yes, from chatgpt: These are so-called “radiative cooling paints.” Here’s how they work: They reflect almost all sunlight, so the surface doesn’t heat up. At the same time, they emit thermal radiation in a specific infrared range (around 8–13 micrometers) that can pass through the Earth’s atmosphere and escape into space. Such paint can make surfaces cooler than the surrounding air, even in sunlight. So it doesn’t convert solar energy into another form — it selectively reflects and emits infrared radiation that sends heat directly into space.
- deleted 1y ago
  [deleted]
Razengan 1y ago
I remember reading something interesting, in a good way, but I'm not sure whether it's fully accurate: That the majority of the planet (land, not counting water) is still unpopulated by people. Can someone verify?
- T-A 1y ago
  Depends on how you measure it. Do you subdivide all land in 1 cm squares and only count the ones with somebody standing on them as populated? Then almost all land is unpopulated. With 8.2 billion people in the world, each one occupying a 0.5x0.5 meter square, you have 2.05e9 m^2 populated land, out of Earth's total land area ~1.5e14 m^2 [1]. That's less than 0.0014%. As you increase the size of your subdivisions, the unpopulated fraction goes down. In the limit of all land being in just one subdivision, it's obviously 0. [1] https://en.wikipedia.org/wiki/Population_density https://en.wikipedia.org/wiki/Population_density
  - Razengan 1y ago
    These type of calculations don't really work for things like skyscrapers, high-rise apartment complexes, or the slum-towns of Asia and South America, and conversely for very sparsely populated regions like the fringes of the Sahara. Antarctica has people too but it doesn't make any sense to count it as "populated". I think we can just draw an outline around cities, towns, and villages and count that area as populated, no matter how many people are actually in there. For long stretches of land where there's just a single highway going through and a few gas stations, motels and shacks, totaling maybe <100 people for many miles around, we can count that land as unpopulated. Isolated islands with indigenous/uncontacted tribes, not sure.. We may have to consider their population growth and see if they're in "equilibrium" with "nature" and so on. A simple glance at Google Earth shows large parts of Russia as clearly unpopulated/undelevoped, then there's the deserts of China and Africa, and some natural land in the Americas, and finally of course there's Antarctica, until the Elder Things awaken.
- marklit 1y ago
  The US has only used 25% of its land. Overture published a land use dataset a while back that could go some way to verify how much land on earth is urban, covered in forest, etc.. That might only need a single SQL statement given how they structured their data. I have some analysis around that topic in the middle of this post: https://tech.marksblogg.com/overture-land-cover.html https://tech.marksblogg.com/overture-land-cover.html
master_crab 1y ago
The 151M Buildings for the US is a bit of a surprise for me. I found it interesting the disparity between the number of buildings in India and the rest of the world (3 times the next country). And the close parity in number between China and the US.
- marklit 1y ago
  From what I've seen in news reports, China has built a lot of tower blocks that are 10s of floors, rather than the 4-5-floor buildings I saw when I worked in and travelled around India. India has ~4x the population of the US so the ratio of buildings isn't much of a surprise.
klabetron 1y ago
Meta note: don’t see many blog posts as detailed as OP with seemingly mundane details. It assumes almost nothing of the user. So many posts would just say “install this QGIS plugin” with no mention of the pip calls, etc. Not sure if this comes from search engine optimisation or years of experience consulting to clients that know nothing :) Anyway, good work Mark. Another of your posts I’ll bookmark.

148 points by marklit 1y ago

AI is responsible for 60% of all internet traffic this morning, OP is the other 40%. But on a serious note this is an interesting project highlighting the sheer volume of power usage across the world. .. I'm also curious given the data and power usage, if AI assisted heatmap is actually more accurate than one developed by downloading a single dataset of high resolution satellite imagery at night, performing algorithmic analysis to draw heatmap based on light output or !maybe even simple image processing downsampling the image and shifting white-blue to red?

marklit 1y ago
70% of daytime RGB sat imagery is covered by clouds. I'm not sure how easy it would be to spot if clouds were covering a city's lights at night. I've only seen Maxar publish one night time image and that was of Dubai. I suspect smaller buildings in not so well lit areas could end up getting missed out. SAR imagery would work well for seeing at night and through clouds but I'm not sure what the state of AI building footprint detection is with SAR atm.
- chasing0entropy 1y ago
  Fascinating. So no such satellite data exists. Thanks for the insight, makes the linked write up much more satisfying.

Qem 1y ago

> The United Nations (UN) believes there are 4B buildings on Earth. This week, a dataset called "GlobalBuildingAtlas" (GBA) was published by researchers at the Technical University of Munich (TUM) that attempts to estimate this number at being closer to 2.75B. If we painted the roofs on all of them white, by how much would the temperature of the planet drop?

csmoak 1y ago
there is a cool project that explores this topic: https://coolcolors.lbl.gov/ https://coolcolors.lbl.gov/
jl6 1y ago
Probably not as much as if we “painted” them black with solar panels and used the resulting electricity to displace fossil fuel burning.
- marklit 1y ago
  A good percentage of Pakistan did this recently and removed 35% of demand off of their grid https://www.ted.com/talks/jenny_chase_solar_energy_is_even_cheaper_than_you_think/transcript https://www.ted.com/talks/jenny_chase_solar_energy_is_even_c...
  - mcny 1y ago
    I would love to have an air conditioning / cooling solution that is directly linked to solar panels with no batteries involved. Like the sun shines, we get electricity, we do the work. My main goal for this thought experiment is to come up with uses of solar electricity that is resilient to the unpredictable and unreliable energy generation from solar. Thoughts?
    - bragr 1y ago
      Though experiment? This is already a thing in the off grid community. In practice you need at least small battery to smooth out the power, but it doesn't take much home automation to kick on the mini split when the panels/inverters have power to spare.
    - Qem 1y ago
      > I would love to have an air conditioning / cooling solution that is directly linked to solar panels with no batteries involved. I think that would be very viable with fridges, that represent a large share of electricity consumption among the poorest. Before electricity, people powered fridges by constantly buying ice blocks. They were just isolated boxes where food was stored together with the blocks. Perhaps it's just necessary to go back at the roots, and make fridges that take energy from solar panels and generate a lot of ice by day, and uses it to keep cold at night, with no need for batteries.

jtwaleson 1y ago

Ok a bit off topic but isn't a 1200W PSU overkill for this system? For a 9950X and 1080, 500W seems plenty.

nixass 1y ago
I see it says Corsair so cannot tell what exact model it is but I did relatively similar thing. Reason being if you keep the load under certain wattage the PSU will run in passive cooling mode. My rig will never reach 50% of what Corsair SF750 Platinum can deliver and not mention in normal light load circumstances. It spins up its fans only when the load reaches ~300W or so. Some people are very anal about any kind of noise coming out of their rigs. I personally undervolt everything to keep the fans at bay/minimum and having extra legroom in PSU department helps a lot
- zamadatix 1y ago
  Same. Part of the background info on this is PSUs are usually most efficient at (or just under) 50% load. They are also more efficient at 240 V than 120 V, if you have the circuit. So the real efficiency can end up varying significantly, depending how you use it. The efficiency is not usually much to write home about in terms of your electric bill, but it does help drive the ability for the PSU to cool itself passively.
marklit 1y ago
I'm hoping to use most of this system for the next 10 years. At some point, I want to add some beefy GPUs to it when I get back into 3D again.

jongjong 1y ago

Kind of crazy to think that there are almost half as many buildings as people and yet me and my wife can't even afford the deposit to buy a single one on a mortgage after 10 years of saving, hustling hard, taught myself to code, got a university degree, worked in the tech sector, near the forefront of all the hot tech tends... Meanwhile, all this time, I'm told I'm privileged. I must be the victim of some kind of massive PsyOp conspiracy.

dyauspitr 1y ago
You can buy a small house in rural America for $25,000
- trallnag 1y ago
  Rural Russia as well. But you will probably have to get your water from a well and poop into a latrine.
  - deleted 1y ago
    [deleted]
- jongjong 1y ago
  In my country (Australia), the cheapest I can get is like $250k USD equivalent... But that's a shack in the middle of the desert in some tiny ghost town. Even in a normal small town, houses are like $350k USD minimum. In capital cities, it's like $500k USD minimum for a tiny apartment... Top salaries for top senior software devs are like $130k USD before tax, taxed at about 40%... So take home pay is like $78k USD net income. Rent is like $22k per year minimum. Impossible to get fixed-rate mortgages; banks only only do variable rate... 20% minimum deposit. This is in a country with a LOT of spare land which is scarcely populated.
  - RobGR 1y ago
    Your country exports timber to China and has a lot of empty land. Who benefits from this situation ?

Gys 1y ago

Is it possible to calculate from that data the total surface area of all roofs? I think there is paint that converts solar energy into radiation that goes straight back into space. I wonder if using that paint on a significant percentage of buildings would matter.

Llamamoe 1y ago
Are you perhaps thinking of radiative cooling, e.g. paint that reflects close to 100% of all light, excluding the spectrum at which room-temperature objects radiate heat, resulting in a net cooling effect? E.g. [Revolutionary Paint: How to Make Surfaces Stay Cool in the Sun](https://youtu.be/dNs_kNilSjk https://youtu.be/dNs_kNilSjk)
- Gys 1y ago
  Thanks for the video! Yes, from chatgpt: These are so-called “radiative cooling paints.” Here’s how they work: They reflect almost all sunlight, so the surface doesn’t heat up. At the same time, they emit thermal radiation in a specific infrared range (around 8–13 micrometers) that can pass through the Earth’s atmosphere and escape into space. Such paint can make surfaces cooler than the surrounding air, even in sunlight. So it doesn’t convert solar energy into another form — it selectively reflects and emits infrared radiation that sends heat directly into space.
deleted 1y ago
[deleted]

Razengan 1y ago

I remember reading something interesting, in a good way, but I'm not sure whether it's fully accurate: That the majority of the planet (land, not counting water) is still unpopulated by people. Can someone verify?

T-A 1y ago
Depends on how you measure it. Do you subdivide all land in 1 cm squares and only count the ones with somebody standing on them as populated? Then almost all land is unpopulated. With 8.2 billion people in the world, each one occupying a 0.5x0.5 meter square, you have 2.05e9 m^2 populated land, out of Earth's total land area ~1.5e14 m^2 [1]. That's less than 0.0014%. As you increase the size of your subdivisions, the unpopulated fraction goes down. In the limit of all land being in just one subdivision, it's obviously 0. [1] https://en.wikipedia.org/wiki/Population_density https://en.wikipedia.org/wiki/Population_density
- Razengan 1y ago
  These type of calculations don't really work for things like skyscrapers, high-rise apartment complexes, or the slum-towns of Asia and South America, and conversely for very sparsely populated regions like the fringes of the Sahara. Antarctica has people too but it doesn't make any sense to count it as "populated". I think we can just draw an outline around cities, towns, and villages and count that area as populated, no matter how many people are actually in there. For long stretches of land where there's just a single highway going through and a few gas stations, motels and shacks, totaling maybe <100 people for many miles around, we can count that land as unpopulated. Isolated islands with indigenous/uncontacted tribes, not sure.. We may have to consider their population growth and see if they're in "equilibrium" with "nature" and so on. A simple glance at Google Earth shows large parts of Russia as clearly unpopulated/undelevoped, then there's the deserts of China and Africa, and some natural land in the Americas, and finally of course there's Antarctica, until the Elder Things awaken.
marklit 1y ago
The US has only used 25% of its land. Overture published a land use dataset a while back that could go some way to verify how much land on earth is urban, covered in forest, etc.. That might only need a single SQL statement given how they structured their data. I have some analysis around that topic in the middle of this post: https://tech.marksblogg.com/overture-land-cover.html https://tech.marksblogg.com/overture-land-cover.html

master_crab 1y ago

The 151M Buildings for the US is a bit of a surprise for me. I found it interesting the disparity between the number of buildings in India and the rest of the world (3 times the next country). And the close parity in number between China and the US.

marklit 1y ago
From what I've seen in news reports, China has built a lot of tower blocks that are 10s of floors, rather than the 4-5-floor buildings I saw when I worked in and travelled around India. India has ~4x the population of the US so the ratio of buildings isn't much of a surprise.

klabetron 1y ago

Meta note: don’t see many blog posts as detailed as OP with seemingly mundane details. It assumes almost nothing of the user. So many posts would just say “install this QGIS plugin” with no mention of the pip calls, etc. Not sure if this comes from search engine optimisation or years of experience consulting to clients that know nothing :) Anyway, good work Mark. Another of your posts I’ll bookmark.