Carbon Sequestration ...

... new technique for storing carbon dioxide identified.

In his small-scale reactor, Van Essendelft grinds a serpentine rock mixed with water and acid. The combination of grinding and chemical action (mainly the acid) breaks down serpentine into magnesium and silica, which is essentially sand. He then adds ammonia and pumps CO2 in. The ammonia neutralizes the acid, allowing the CO2 to dissolve and react with magnesium, forming magnesium carbonate.

Magnesium carbonate is similar to chalk and has several applications. For example, Van Essendelft says, it could be used instead of limestone to produce cement.

This would be an interesting means of carbon sequestration for anaerobic digestion (AD) on-farm. You already have a surplus of ammonia from the animal waste, and about 35% of the bio-gas from AD is carbon dioxide.

Atlantic Ocean bigger carbon sink ...

... than previously expected.

Moreover, much of this carbon ends up in long-term storage instead of being recycled quickly like most carbon in the ocean. That's because the main photosynthesisers are diatoms, single-celled algae that build a heavy silica shell around their bodies.

This glassy shell makes diatoms sink rapidly after they die, removing 20 million tonnes of carbon from the atmosphere each year, the researchers estimate.

That's not much compared to the amount emitted by human activity each year but it represents a major shift in our knowledge of the oceans' carbon balance, says Subramanian. And although the Amazon is the largest of the world's rivers, other major tropical rivers such as the Congo and the Orinoco may have similar effects, he says – a conjecture he is now aiming to test.

Now, time to use this to our advantage.