(Even if cloud brightening is the ultimate solution to warming, we still need to address ocean acidification and carbon sequestration, and I’m not aware of any ideal solution to those problems yet, but two weeks ago I wasn’t aware of cloud brightening, so for all I know the problem isn’t a lack of investment, might just be a lack of policy discussion.)
There is also http://projectvesta.org which claims that it is possible to remove CO2 from the ocean and atmosphere via olivine weathering reasonably cheaply.
They propose mining and transporting 11 cubic kilometers* of olivine per year, at $10 per ton when scaled up, which comes out to $365 billion per year assuming that’s metric tonnes. Might or might not be considered “reasonably cheaply” depending on what you think of the alternatives.
*they also mention 7 cubic miles, which would be almost a trillion dollars per year, but this would be a lot more than would be needed to offset world carbon emissions if their claim of 1.25 to 1 ratio of CO2 to olivine is correct—so I think that’s a misconversion from the 11 cubic km figure rather than the other way around.
For some further perspective, $10 per ton at 1.25 times removal of CO2 would be $8 per ton of CO2. So, we could theoretically pay for it with a relatively affordable $8 per ton global carbon tax if that could somehow be made to work politically.
There is also http://projectvesta.org which claims that it is possible to remove CO2 from the ocean and atmosphere via olivine weathering reasonably cheaply.
They propose mining and transporting 11 cubic kilometers* of olivine per year, at $10 per ton when scaled up, which comes out to $365 billion per year assuming that’s metric tonnes. Might or might not be considered “reasonably cheaply” depending on what you think of the alternatives.
*they also mention 7 cubic miles, which would be almost a trillion dollars per year, but this would be a lot more than would be needed to offset world carbon emissions if their claim of 1.25 to 1 ratio of CO2 to olivine is correct—so I think that’s a misconversion from the 11 cubic km figure rather than the other way around.
For some further perspective, $10 per ton at 1.25 times removal of CO2 would be $8 per ton of CO2. So, we could theoretically pay for it with a relatively affordable $8 per ton global carbon tax if that could somehow be made to work politically.