It seems like the only things that can 1. work at a planetary scale 2. mitigate our multi-year (and growing) emission problem 3. not on an energy flywheel (co

It seems like the only things that can 1. work at a planetary scale 2. mitigate our multi-year (and growing) emission problem 3. not on an energy flywheel (consume a significant amount of energy, mined resources or themselves emit significant waste heat) have to rely directly on solar energy (not intermediated by PV cell). To this end azolla ferns [1] and olivine weathering seem to be the most promising. [1] https://en.m.wikipedia.org/wiki/Azolla_event https://en.m.wikipedia.org/wiki/Azolla_event