The question only refers to CO2 sequestration via Direct Air Capture (DAC). The solution must be scalable. I'll define scalable as there existing somewhere in the world that "could" produce 100,000+ tonnes at such a price. There doesn't have to be such a system in place; there must only be consensus among experts that such a system is possible.

Current estimates are that CO2 costs between 600-1000 USD per tonne [1]. I will resolve this when the price drops to 60 USD per tonne adjusting for inflation. If the threshold is not clearly surpassed within one of the above periods, I reserve the right to resolve two time periods as being correct.

[1] https://www.weforum.org/agenda/2023/08/how-to-get-direct-air-capture-under-150-per-ton-to-meet-net-zero-goals/

Achieving net zero: Why costs of direct air capture need to drop for large-scale adoption

Direct air capture is one of the world's most effective carbon dioxide removal methods, but costs need to drop to accelerate its adoption and scale-up.