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Trying to bury a significant portion of the global plant mass gain every year in a way that it does not emit greenhouse gases while decomposing seems like a maj
by danbruc 10y ago
Trying to bury a significant portion of the global plant mass gain every year in a way that it does not emit greenhouse gases while decomposing seems like a major undertaking to me.
A quick calculation - one ppm reduction means extracting three trillion metric tons of carbon dioxide which contains about 800 billion tons of pure carbon which takes up about 400 cubic kilometers. That is a huge hole to dig even if we would just have to deal with the carbon. And that is for one ppm.
- clock_tower 10y agoDon't we have plenty of old coal mines? They seem like a natural place to sequester carbon in, given that that's where a lot of it came from in the first place...
- ars 10y ago> three trillion metric tons of carbon dioxide Billion not trillion (10^9). All the rest of your numbers are off by a similar factor. > That is a huge hole to dig Actually, using the correct numbers (.4 cubic km), if you made a 50 foot deep hole it would be about 3 miles by 3 miles. Not that big - a couple of city blocks. A typical landfill is larger than that, and we have tons of those.
- danbruc 10y agoNope, trillions. The mass of the atmosphere is about 5.15 × 10¹⁸ kg [1], 400 ppm of that are 2.06 x 10¹⁵ kg or 2.06 x 10¹² t which are about two trillion (short scale) or two billion (long scale) metric tons. I used the short scale [2]. And because the 400 pm are by volume and not by mass you end up with about three trillion metric tons if you take that into account, too. Of course only unless I messed things up. [1] https://en.wikipedia.org/wiki/Atmosphere_of_Earth https://en.wikipedia.org/wiki/Atmosphere_of_Earth [2] https://en.wikipedia.org/wiki/Long_and_short_scales https://en.wikipedia.org/wiki/Long_and_short_scales