Extracting carbon dioxide

Not surprisingly, perhaps, Tim Lenton et al endorse biochar [1]. 

Bearing in mind that it would only reduce radiative forcing by 0.4 W/m2 by 2100, and that in this timeframe emissions may bring 'irreversible' climate chaos [2], increased research into the options for extracting CO2 from the atmosphere (which, it's calculated, could reduce radiative forcing by 1.9 W/m2 by 2100) looks almost sensible. Could/should an [international] fund for mitigation and adaptation, with revenue from carbon auctions, explicitly include support for this?

Footnote

[1] "The basic trend", writes James Hrynyshyn, "is the more feasible the idea, the smaller the contribution it can make."

[2] (added 1 Feb) Realclimate notes that 'Irreversible' Does Not Mean Unstoppable.