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We add carbon dioxide to the atmosphere through fossil fuel combustion. About 40% of this carbon stays in the atmosphere and roughly 30% enters the ocean, and we are not too sure where all the rest goes.
Most scientists thought the remaining carbon was taken up by plants, but measurements show plants don't absorb all of the remaining 30% of carbon we generate.
Lots of theories have been expounded about where the leftover carbon is being stored.
A study published in Geophysical Research Letters suggests some of this carbon may be disappearing underneath the world's deserts – a process exacerbated by irrigation, beginning as recently as 2000 years ago.
When cultivating and irrigating arid/saline lands in arid zones, salts are leached downward. Simultaneously, dissolved inorganic carbon is washed down into the huge saline aquifers underneath vast deserts, forming a large carbon sink or pool.
Researchers studying the Tarim Basin in China, found that around 20 billion metric tons of carbon is stored underneath the desert, dissolved in an aquifer that contains roughly ten times the amount of water held in the Great Lakes.
This is a carbon sink that is not observable in plant or soil, with dissolved inorganic carbon (DIC) leached from irrigated arid land and deposited in the saline/alkaline aquifers under bare deserts. For the most part, this is a one way trip for the carbon. No mechanism has been identified for return to the surface or the atmosphere.
More importantly, the DIC goes into an almost untouched pool in saline/alkaline aquifers hidden beneath deserts, which is estimated to be up to 1000 Pg (1,102,311,310 kilotons) globally, large enough to be recognized as the third largest active carbon pool on land.
Such carbon sinks formed during groundwater recharge has been reported before. But never on this scale.
The amount of dissolved inorganic carbon stored is 1 to 2 orders of magnitude higher than previously thought.
(Score: 2) by richtopia on Tuesday December 22 2015, @03:11PM
Carbon capture is typically a net loss operation, with most methods putting more carbon in the air than what is taken out. Perhaps if we understand this process we may be able to mimic it in the future.
(Score: 1) by khallow on Tuesday December 22 2015, @05:28PM
Carbon capture is typically a net loss operation, with most methods putting more carbon in the air than what is taken out.
That's only because a large portion are fraudulent or superficially done for ulterior reasons. For example, Russia and Ukraine have been banned [soylentnews.org] for some indefinite time from selling carbon offset credits to European carbon emission markets, because a large portion of their previous efforts were for stuff that had been done years earlier or in some cases, probably didn't actually happen at all. I figure that deception was probably worth a few billion dollars to the involved parties.
(Score: 3, Informative) by frojack on Tuesday December 22 2015, @06:34PM
Carbon offsets have nothing to do with carbon capture.
Carbon Credits: https://en.wikipedia.org/wiki/Carbon_credit [wikipedia.org]
Carbon Capture: https://en.wikipedia.org/wiki/Carbon_capture_and_storage [wikipedia.org]
Realistically, carbon capture only works for large carbon producing industry (energy generation), and contrary to the assertion above, it is not a net loss. But it is very expensive, and doubles the cost of electricity while causing other forms of pollution (which are being worked on).
No, you are mistaken. I've always had this sig.
(Score: 1, Informative) by Anonymous Coward on Tuesday December 22 2015, @09:30PM
That second Wikipedia page has a paragraph, added in 2012, about saline aquifers (like those being discussed here) as a type of formation that could absorb CO2.
(Score: 1) by khallow on Wednesday December 23 2015, @03:31PM
Carbon offsets have nothing to do with carbon capture.
Aside from being a superset of the latter.