Somebody should do a preliminary cost analysis comparing the cost and effectiveness (and uncertainty therein) for all of these proposals, as a function of setting, discount rate, etc.
These options are not alternatives but complements. Doing more of one does not preclude doing more of another. We would like to be economically efficient, so in any particular setting one option or another is likely to be most cost-effective. It is not obvious that it is very useful to make broad general statements about which of the more sensible options is "better" in an absolute sense, although shooting turkeys is usually a valuable endeavor. On Mon, Sep 26, 2011 at 9:25 AM, Oliver Tickell <[email protected]>wrote: > > Actually this option does not look too bad on first sight - low cost, > low tech, so that's a good start, and the chemistry looks right too. > Biggest problem is the delay of approx 100y before the results come > through, if I read the paper right. That's a long time for us to have > to wait. Also if we change our minds, its a long lead time for > reversal. > > Go for Mg silicate weathering on land / intertidal zones, and the CO2 > drawdown is immediate, operating on a decadal time scale. > > Re the kinetics of Mg silicate, they are unfavourable if carried out > in a chemistry lab. Carried out in nature and enhanced by activity of > fungi, bacteria, roots, digestive systems of worms and higher animals, > etc, it's a great deal faster - the biospheric enhancement factor > speeds it up by several orders of magnitude. > > Oliver. > > On Sep 26, 4:09 pm, "Rau, Greg" <[email protected]> wrote: > > And to round out the options, let’s not forget Harvey’s > limestone-rain-in-the-ocean method: > http://iod.ucsd.edu/courses/sio278/documents/harvey_08_co2_mitigation... > > While billed as (eventual) air capture, I view this as ocean CO2 capture > – bomb upwelling areas with limestone to consume the excess CO2(aq) prior to > degassing to air. Don’t forget that the ocean emits in gross >300 GT > CO2/yr. If we can cut that by 1% it would have a huge effect on air CO2. > No? > > Humbly, > > Greg > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
