Dumping dirt in the ocean to lower CO2 levels

Assuming we need to reduce CO2, this is an interesting and relatively safe way to do it. I do wonder what useful work people could be doing instead, but it could be an interesting experiment.

A dash of lime -- a new twist that may cut CO2 levels back to pre-industrial levels:
"Scientists say they have found a workable way of reducing CO2 levels in the atmosphere by adding lime to seawater. And they think it has the potential to dramatically reverse CO2 accumulation in the atmosphere, reports Cath O'Driscoll in SCI's Chemistry & Industry magazine published today.

Shell is so impressed with the new approach that it is funding an investigation into its economic feasibility. 'We think it's a promising idea,' says Shell's Gilles Bertherin, a coordinator on the project. 'There are potentially huge environmental benefits from addressing climate change – and adding calcium hydroxide to seawater will also mitigate the effects of ocean acidification, so it should have a positive impact on the marine environment.'

Adding lime to seawater increases alkalinity, boosting seawater's ability to absorb CO2 from air and reducing the tendency to release it back again.
. . .
The process of making lime generates CO2, but adding the lime to seawater absorbs almost twice as much CO2. The overall process is therefore 'carbon negative'.

'This process has the potential to reverse the accumulation of CO2 in the atmosphere. It would be possible to reduce CO2 to pre-industrial levels,' Kruger says.
. . .
The oceans are already the world's largest carbon sink, absorbing 2bn tonnes of carbon every year. Increasing absorption ability by just a few percent could dramatically increase CO2 uptake from the atmosphere.

This project is being developed in an open source manner. To find out more, please go to http://www.cquestrate.com , a new website, launched today."