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Just as burning fossil fuels cause dangerous reconfiguration of earth's atmosphere, I think that the idea of a hydrogen economy requires careful thought. Hydrog

Just as burning fossil fuels cause dangerous reconfiguration of earth's atmosphere, I think that the idea of a hydrogen economy requires careful thought. Hydrogen shares with helium a unique property, that it is at escape velocity at the temperatures of the upper atmosphere. It seems unfathomable now, but if we converted all earths water into hydrogen and oxygen without containment, the planet would become a dead rust ball. It's not that these technologies should not be pursued, merely that adopting any technology on a planetary scale, should require some incredibly serious consideration.

bpodgursky 5y ago
This would only be relevant when the fuel leaks, right? During normal combustion the hydrogen is never exposed to the open atmosphere, it is burned back into H2O and released in that form.
- nine_k 5y ago
  Yes. But one should be aware that leaking some hydrogen is leaking it to the outer space, for good. This realization does not stop us from using much more rare helium in party balloons, though.
  - XorNot 5y ago
    The sheer amount of hydrogen you would have to put into the atmosphere for this to become a problem is enormous. This is a problem in the same sense that the sun going red giant is a problem.
    - JumpCrisscross 5y ago
      > This is a problem in the same sense that the sun going red giant is a problem To be fair to OP, at the point we're concerned about Exxon Valdez circa 2400 dumping an atmosphere of hydrogen into space and the Sun's expansion, we could solve one problem with the other and bring the Sun's mass over.
      - rbanffy 5y ago
        If we learn how to remove mass from the Sun at a large scanner, we can extend its useful life and fuse the hydrogen into more useful materials. We can prevent it from going red giant in the first place.
  - Robotbeat 5y ago
    That's not really true. Hydrogen oxidizes in the atmosphere, whereas helium does not. Also, helium is continually produced via nuclear decay in the Earth, and it seeps up through the crust. So it's rare and it leaks into space with or without humans.
- GravitasFailure 5y ago
  Losing Earth's hydrogen to space would require a stupendously long wait. Maybe freeing all of it at once would help speed the process asking, but the first lightning strike, volcanic eruption, or meteor would just ignite it all back to water. I'd be far more worried about getting struck by lighting, a volcanic eruption or a meteor, than losing our hydrogen to space.
  - SlowRobotAhead 5y ago
    I think scale is a really hard thing for us, but yes, being concerned about this is quite silly.
vimacs2 5y ago
A civilisation capable of significant depletion of the earth's oceans for the production of hydrogen and oxygen is so far ahead of us in economies of scale that we would be long past the point of needing to worry about something that could (to the point of view of such a civilisation) be trivially solved with an air wall or a secondary low earth orbit artificial magnetosphere.
- alpineidyll3 5y ago
  I think you should look at plots of CO2 emissions over time. Life is very efficient at exploiting resources in an exponential fashion, when they become available.
  - vimacs2 5y ago
    I assume by "life", you mean post-industrial revolution humanity which shouldn't be treated as the norm, for either life nor even human history. It's also irrelevant, water is incredibly abundant in our solar system and we don't even have the largest oceans on Earth, they're just the largest ones on the surface.
    - jodrellblank 5y ago
      Are you saying there’s an underground ocean bigger than the Pacific? Where is it?
      - fogihujy 5y ago
        The oceans on Europa cover a smaller area than Earth's oceans, but they contain a larger volume of water as they're much deeper.
        vimacs2 5y ago
        Yes and Ganymede appears to contain concentric layers of oceans separated by layers of ice. There is also Callisto, Encaeladus, Titan, and since New Horizons, potentially even Pluto - not to mention that the trace amounts of H20 present in the sun would outweigh all of it a thousand fold. Bottom line is that water is never in short supply. Nitrogen is likely to be the real bottleneck in our future efforts at colonisation and terraforming - at least till if/when we master star lifting of resources. At that point, mass and energy no longer make meaningful limiters and waste heat disposal becomes the primary menace to further development.
Robotbeat 5y ago
It's worth pointing out that hydrogen oxidizes in the atmosphere, unlike helium, so it won't escape as readily. Secondly, the Sun already splits water into hydrogen and oxygen with UV at some low rate, and that has been going on for literally billions of years from now. I don't think this aspect of what you're talking about will matter before 200 million years from now or so when the Sun becomes intense enough to kick off runaway greenhouse effect (even without human effects) unless we produce so much hydrogen (and leak it) that waste heat of civilization becomes the limiting factor. There are other things to worry about.
deleted 5y ago
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jandrese 5y ago
I just love the thought of some silly human not putting the gas cap on correctly and whoops, we've allowed all of the hydrogen in all of the Earth's oceans to escape and now the atmosphere is way over-oxygenated and everything is always on fire. It's like worrying that astronomers won't be able to enjoy the night sky after we've built a Dyson Sphere.
- quickthrower2 5y ago
  I’ve seen lots of opinion here but no one has whipped out a spreadsheet and run some numbers.
  - jandrese 5y ago
    Energy required to Elecrolyze the world's oceans. Theoretical max efficiency: 13.173 MJ/kg of water.[1] Water in the oceans: 1.35E21 kg [2] Total energy needed to electrolyze the oceans: 1.77E22 MJ Total energy recieved by the Earth from the sun per second: 4.3E14 MJ Time required to elecroyize the oceans using the entire available output of the Sun on Earth at 100% total efficiency: 478.67 days It is a very silly idea to think that we could accidentally wield many orders of magnitude more energy than humanity has ever harnessed in collective history without noticing. [1] https://physics.stackexchange.com/questions/24624/water-electrolysis-calculations https://physics.stackexchange.com/questions/24624/water-elec... [2] https://mathblag.wordpress.com/2013/08/03/how-much-water-is-in-the-oceans/ https://mathblag.wordpress.com/2013/08/03/how-much-water-is-...
yc12340 5y ago
It is incredible, how HN community (arguably made from some of the lest dumb people on Internet) can turn blind eye to this major concern while laughing and patting themselves on their backs. I guess, industrial magnates of 1800s would have shown the same reaction, if someone told them about dangers of burning fossil fuels. "This is ridiculous!", "But Sun was causing fires for centuries!" and "If it gets bad, we can stop burning more coal!" — those excuses didn't age well, yet most replies to this comment repeat them almost verbatim. Of course, instantly sending all (or most) of Earth hydrogen into outer space is impossible — at the current technology level. But wasting what little water we have to make it is still a bad idea. Many places are already short on fresh water — the kind of water, necessary for electrolysis. We can make hydrogen from saltwater too — after purifying it, but that's not commercially viable. No one uses "free" energy from solar panels to make new lakes or refill depleting aquifers. Most of the Earth's surface is covered by water, but we can't even purify enough to satisfy our biological needs — otherwise Sahara would be a major agricultural and economical attraction. To solve world's water problem would require near-unlimited power, and the hydrogen production is not going to do it. At best, a hydrogen boom would result in another round of colonial robbery: stealing water from people, who can't defend it, to power more air conditioners in USA and Europe.
- perilunar 5y ago
  > Of course, instantly sending all (or most) of Earth hydrogen into outer space is impossible — at the current technology level. But wasting what little water we have to make it is still a bad idea. The whole point of making hydrogen (from water) to store energy is so we can release the energy later — by oxidising it back into water. We get the same amount of water back afterwards. No one is going to be stealing water to make hydrogen.
zentiggr 5y ago
If we as a species develop enough to be able to electrolyze a significant enough portion of all of Earth's water for this problem to arise, it's almost a given that we have developed technologies that no longer require us to stay on Earth. Plus hydrogen chemistry, as others have mentioned, will stop at least 99% of the losses you propose simply by reoxidizing in the presence of free oxygen. Helium is inert and doesn't react, therefore is much more likely to be lost to diffusion.

bpodgursky 5y ago

This would only be relevant when the fuel leaks, right? During normal combustion the hydrogen is never exposed to the open atmosphere, it is burned back into H2O and released in that form.

nine_k 5y ago
Yes. But one should be aware that leaking some hydrogen is leaking it to the outer space, for good. This realization does not stop us from using much more rare helium in party balloons, though.
- XorNot 5y ago
  The sheer amount of hydrogen you would have to put into the atmosphere for this to become a problem is enormous. This is a problem in the same sense that the sun going red giant is a problem.
  - JumpCrisscross 5y ago
    > This is a problem in the same sense that the sun going red giant is a problem To be fair to OP, at the point we're concerned about Exxon Valdez circa 2400 dumping an atmosphere of hydrogen into space and the Sun's expansion, we could solve one problem with the other and bring the Sun's mass over.
    - rbanffy 5y ago
      If we learn how to remove mass from the Sun at a large scanner, we can extend its useful life and fuse the hydrogen into more useful materials. We can prevent it from going red giant in the first place.
- Robotbeat 5y ago
  That's not really true. Hydrogen oxidizes in the atmosphere, whereas helium does not. Also, helium is continually produced via nuclear decay in the Earth, and it seeps up through the crust. So it's rare and it leaks into space with or without humans.
GravitasFailure 5y ago
Losing Earth's hydrogen to space would require a stupendously long wait. Maybe freeing all of it at once would help speed the process asking, but the first lightning strike, volcanic eruption, or meteor would just ignite it all back to water. I'd be far more worried about getting struck by lighting, a volcanic eruption or a meteor, than losing our hydrogen to space.
- SlowRobotAhead 5y ago
  I think scale is a really hard thing for us, but yes, being concerned about this is quite silly.

vimacs2 5y ago

A civilisation capable of significant depletion of the earth's oceans for the production of hydrogen and oxygen is so far ahead of us in economies of scale that we would be long past the point of needing to worry about something that could (to the point of view of such a civilisation) be trivially solved with an air wall or a secondary low earth orbit artificial magnetosphere.

alpineidyll3 5y ago
I think you should look at plots of CO2 emissions over time. Life is very efficient at exploiting resources in an exponential fashion, when they become available.
- vimacs2 5y ago
  I assume by "life", you mean post-industrial revolution humanity which shouldn't be treated as the norm, for either life nor even human history. It's also irrelevant, water is incredibly abundant in our solar system and we don't even have the largest oceans on Earth, they're just the largest ones on the surface.
  - jodrellblank 5y ago
    Are you saying there’s an underground ocean bigger than the Pacific? Where is it?
    - fogihujy 5y ago
      The oceans on Europa cover a smaller area than Earth's oceans, but they contain a larger volume of water as they're much deeper.
      - vimacs2 5y ago
        Yes and Ganymede appears to contain concentric layers of oceans separated by layers of ice. There is also Callisto, Encaeladus, Titan, and since New Horizons, potentially even Pluto - not to mention that the trace amounts of H20 present in the sun would outweigh all of it a thousand fold. Bottom line is that water is never in short supply. Nitrogen is likely to be the real bottleneck in our future efforts at colonisation and terraforming - at least till if/when we master star lifting of resources. At that point, mass and energy no longer make meaningful limiters and waste heat disposal becomes the primary menace to further development.

Robotbeat 5y ago

It's worth pointing out that hydrogen oxidizes in the atmosphere, unlike helium, so it won't escape as readily. Secondly, the Sun already splits water into hydrogen and oxygen with UV at some low rate, and that has been going on for literally billions of years from now. I don't think this aspect of what you're talking about will matter before 200 million years from now or so when the Sun becomes intense enough to kick off runaway greenhouse effect (even without human effects) unless we produce so much hydrogen (and leak it) that waste heat of civilization becomes the limiting factor. There are other things to worry about.

deleted 5y ago

[deleted]

jandrese 5y ago

I just love the thought of some silly human not putting the gas cap on correctly and whoops, we've allowed all of the hydrogen in all of the Earth's oceans to escape and now the atmosphere is way over-oxygenated and everything is always on fire. It's like worrying that astronomers won't be able to enjoy the night sky after we've built a Dyson Sphere.

quickthrower2 5y ago
I’ve seen lots of opinion here but no one has whipped out a spreadsheet and run some numbers.
- jandrese 5y ago
  Energy required to Elecrolyze the world's oceans. Theoretical max efficiency: 13.173 MJ/kg of water.[1] Water in the oceans: 1.35E21 kg [2] Total energy needed to electrolyze the oceans: 1.77E22 MJ Total energy recieved by the Earth from the sun per second: 4.3E14 MJ Time required to elecroyize the oceans using the entire available output of the Sun on Earth at 100% total efficiency: 478.67 days It is a very silly idea to think that we could accidentally wield many orders of magnitude more energy than humanity has ever harnessed in collective history without noticing. [1] https://physics.stackexchange.com/questions/24624/water-electrolysis-calculations https://physics.stackexchange.com/questions/24624/water-elec... [2] https://mathblag.wordpress.com/2013/08/03/how-much-water-is-in-the-oceans/ https://mathblag.wordpress.com/2013/08/03/how-much-water-is-...

yc12340 5y ago

It is incredible, how HN community (arguably made from some of the lest dumb people on Internet) can turn blind eye to this major concern while laughing and patting themselves on their backs. I guess, industrial magnates of 1800s would have shown the same reaction, if someone told them about dangers of burning fossil fuels. "This is ridiculous!", "But Sun was causing fires for centuries!" and "If it gets bad, we can stop burning more coal!" — those excuses didn't age well, yet most replies to this comment repeat them almost verbatim. Of course, instantly sending all (or most) of Earth hydrogen into outer space is impossible — at the current technology level. But wasting what little water we have to make it is still a bad idea. Many places are already short on fresh water — the kind of water, necessary for electrolysis. We can make hydrogen from saltwater too — after purifying it, but that's not commercially viable. No one uses "free" energy from solar panels to make new lakes or refill depleting aquifers. Most of the Earth's surface is covered by water, but we can't even purify enough to satisfy our biological needs — otherwise Sahara would be a major agricultural and economical attraction. To solve world's water problem would require near-unlimited power, and the hydrogen production is not going to do it. At best, a hydrogen boom would result in another round of colonial robbery: stealing water from people, who can't defend it, to power more air conditioners in USA and Europe.

perilunar 5y ago
> Of course, instantly sending all (or most) of Earth hydrogen into outer space is impossible — at the current technology level. But wasting what little water we have to make it is still a bad idea. The whole point of making hydrogen (from water) to store energy is so we can release the energy later — by oxidising it back into water. We get the same amount of water back afterwards. No one is going to be stealing water to make hydrogen.

zentiggr 5y ago

If we as a species develop enough to be able to electrolyze a significant enough portion of all of Earth's water for this problem to arise, it's almost a given that we have developed technologies that no longer require us to stay on Earth. Plus hydrogen chemistry, as others have mentioned, will stop at least 99% of the losses you propose simply by reoxidizing in the presence of free oxygen. Helium is inert and doesn't react, therefore is much more likely to be lost to diffusion.