Here’s another potentially very big and completely different carbon capture idea, although still in early stages.
https://www.wired.com/story/the-plan...harged-plants/
“Unlike engineered solutions, biology harnesses evolutionary time, because plants have already evolved for 500 million years to be great at sucking up CO2. In fact, according to the Salk Institute, every year plants and other photosynthetic life capture 746 gigatons of CO2 and then release 727 gigatons of CO2 back. If it weren’t for the 37 gigatons of CO2 humans also release into the atmosphere annually, the global carbon cycle would be healthy... Chory believes the key to fixing that imbalance is to train plants to suck up just a little more CO2 and keep it longer. She is working on engineering the world’s crop plants to have bigger, deeper roots made of a natural waxy substance called suberin—found in cork and cantaloupe rinds—which is an incredible carbon-capturer and is resistant to decomposition. By encouraging plants to have bigger, deeper, more suberin-rich roots, Chory can trick them into fighting climate change as they grow. The roots will store CO2, and when farmers harvest their crops in the fall, those deep-buried roots will stay in the soil and keep their carbon sequestered in the dirt, potentially for hundreds of years... She received an Audacious Project prize of more than $35 million to scale this project... If she and her team can breed these plants and get them into the global agricultural food chain,
Chory believes they can contribute a 20 to 46 percent reduction in excess CO2 emissions annually... The benefits don’t stop there, according to Chory. Those roots will very slowly break down and deposit their carbon little by little in the soil. This could reverse some of the human-caused depletion that has removed carbon and other nutrients from the soil due to agricultural practices that “treat soil like dirt,” to quote UC Merced soil scientist Asmeret Asefaw Berhe...
See also:
https://thebulletin.org/2018/06/a-pl...-if-we-let-it/
This is another area where a modest carbon tax could help. Farmers are likely going to be reluctant to switch to a new plant, and rebating to them $X per tonne of CO2 sequestered would certainly help this go forward. The plants she seems to be talking about first are pulses, like chick peas, beans and lentils, and these are grown mostly in India and Canada.