[bencompanion]

https://en.wikipedia.org/wiki/Biochar production is one approach to this that is low-tech and doesn't require organism engineering. It's kinda counter intuitive that burning a rich source of carbon would keep it out of the atmosphere, but turning organic material into charcoal stabilises it and renders it inedible and insoluble, and it's really useful as a soil amendment in a lot of places, and it's very likely safe to dump in deep ocean if we ever run short of places to put it.

Farmed seaweed and algae > biochar is a very promising sequestration approach, I think.

[21]

Wouldn't this biochar be the charcoal mines of tomorrow?

What I'm saying, is that if it's cheaper than regular coal people will buy this to burn. So you still need an incentive to not burn fossil fuels.

[cschwarm]

Biochar is unlikely to be cheaper than coal, ever. Optimistic long-term estimates are $100 per ton [1].

[1] http://biomassmagazine.com/articles/4080/beyond--the--hype

[mikec3010]

There's nothing wrong with burning a renewable resource. You're still at net 0 carbon emissions.