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Comment by beedeebeedee | Hacker News Reader

I'm not completely sold on it, but one of my friends is adamant that this approach powered by hydrogen deposits make all of our climate change issues (and other societal issues) into non-issues. I just wouldn't want it if it isn't done equitably.

https://www.usgs.gov/news/featured-story/potential-geologic-...

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At a global industrial scale, we're pulling lots of carbon out of the ground for energy and its ending up as carbon dioxide in the atmosphere with big consequences. We should also consider the implications of pulling hydrogen out of the ground at global industrial scales and it ending up as water vapor, trapping atmospheric oxygen in it. Generated hydrogen at least has a closed loop on water and oxygen from the atmosphere.

I don’t think this would be such an issue. There’s about 500x as much oxygen in the air as carbon dioxide.

Increasing the amount of carbon dioxide by 140ppm is a 50% increase in carbon dioxide levels since pre industrial times.

Reducing the about of oxygen, currently at 209,000ppm, by 140ppm seems like it would have a negligible effect.

The far greater likely issue with natural hydrogen is that we simply don’t find any deposits of it that are both significant and economically extractable. And in the mean time we use it as an excuse to not do anything about carbon emissions.

That's a good point. I'm a little hesitant about it being so easy for us to just switch to a different fuel (without a lot of deep reflection and cultural change), and ending up with a different set of unforeseen (or foreseen but ignored) catastrophic consequences.

We pull massive amounts of oxides out of the ground and dump the oxygen too. Iron ore is mostly oxides, for instance.

Long term, all the digging we're doing is pulling down atmospheric O2, by exposing ferrous iron and reduced sulfides, manganese, etc. to oxidation. The amount of crust that would have to be fully oxidized to deplete all atmospheric O2 is surprisingly small, I think just a few hundred meters. Atmospheric O2 is on quite a small scale compared to the reducing power of Earth as a whole.

There are no significant hydrogen deposits. Otherwise, we would have long discovered at least some of them.

Another possibility worth investigating is direct electricity-driven synthesis: https://www.newscientist.com/article/dn25894-meet-the-electr...

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