Six commercially-viable ways to remove CO2 from the atmosphere and/or reduce CO2 emissions

Epic stuff. Nickel farming sounds like a cool thing. Quartz has a similar use and has been used in farming.

http://geo-engineering.blogspot.fr/2014/01/six-commercially-viable-ways-to-remove-co2-from-the-atmosphere-and-or-reduce-co2-emissions.html