From the site Soil Not Oil, of which Shiva is one of the organisers,...Archived Message
Posted by Garry on March 3, 2019, 8:03 pm, in reply to "This bit..."
...two points from a list of eight: "Industrial agricultural soils are in grave danger since on average they have lost 50% of their soil organic matter during the 20th Century. This loss reduces natural productive processes in the soil, while the lost soil carbon has entered the atmosphere as carbon dioxide which may have contributed up to 100ppm of the total 400ppm currently present."
Also this: "Organic regenerative agricultural practices builds up living carbon in soil, mitigates climate change, and has the potential to reduce the accumulated carbon dioxide in the atmosphere to 350ppm based on all farmland and rangelands shifting to regenerative practices."
So based on those two points, we may be able to get back down to between 300 - 350 ppm, if we could immediately stop all fossil fuel use and enable the world's soils to reconstruct themselves. They carefully use the word 'mitigate', not 'solve' the climate crisis. If we could get back down to 300ppm, it would be pretty much solved alright.
I find it hard to see it myself, unless we can get soil to absorb far more carbon than it used to, given all that additional fossil carbon we've put in on top. Is there evidence that it can do that? In any case, it's the direction we need to take, for all sorts of reasons.