The whole idea of carbon sequestration has always been a bust. Perhaps none of you ever saw
An Inconvenient Truth, aka Al Gore's silly movie with the hockey stick curve. Al showed video footage of his visit to a giant drilling platform that would have captured carbon dioxide via fractional distillation from the atmosphere, then pumped liquid carbon dioxide to down below the frigid arctic seabed where it would have formed methane hydrate deposits. The energy budget for this not so-efficient alternative required 350% as much energy as was originally released by burning the FF's.
Al Gore was all set up to make a real killing, he was selling shares and had a stock prospectus for his new venture, which was a company manufacturing the equipment for carbon sequestration via fractional distillation. He called his stock "the greatest investment opportunity since the petroleum boom". He also spoke of mandatory carbon sequestration from every 1st World Country, to exceed all of their total carbon emissions from every source. (Mandated by the UN under the auspices of a newly-empowered IPCC, of course....)
In the real world, those companies which manufacture the equipment to recover the methane hydrates from the ocean floor, then process them for natural gas production, proved to be better investments than was Al Gore's.
For all you AGW fanboys, the deposits of methane hydrates at the polar regions are estimated to contain the majority of carbon on the Earth. Something else for you to screetch about, I suppose.
Meanwhile, there are Geoengineering proposals to reclaim the Antarctic continent, heat it with the natural gas from methane hydrates, and increase the solar insolance via orbital mirrors to where we could grow food and people could live there. There would of course be some sea level rise associated with this, but we can always line all the continents we are actually using now with giant levees and dikes, like this:
That would be REAL GEOENGINEERING, making a planet for 100+ billion humans to live on. We would of course increase the carbon content of the atmosphere to optimize plant growth, and moderate the equatorial temperatures by deflecting some portion of their natural sunlight to the Antarctic. We would be in effect making a colossal A/C for the tropics and making lots more temperate climate zones for humans to live in. Wanna talk about that?