…But in a new report, Oxford University researchers say that our best hopes might not be so complex. In fact, they are two things we already know how to do: plant trees and improve the soil.
Both techniques, said the report, are “no regrets.” They’ll help the atmosphere no matter what, they’re comparatively low-cost, and they carry little additional risk. Specifically, the two techniques it recommends are afforestation—planting trees where there were none before—and biochar—improving the soil by burying a layer of dense charcoal.
Between now and 2050, trees and charcoal are the “most promising” technologies out there, it said….
“It is clear that attaining negative emissions is in no sense an easier option than reducing current emissions,” it says (emphasis mine).”
“To remove CO2 on a comparable scale to the rate it is being emitted inevitably requires effort and infrastructure on a comparable scale to global energy or agricultural systems.”
This paper is now 15 months old but gets a fresh critique here
by Dr Ronal Larsen, an advocate and expert on biochar for carbon sequestration.