List cc Keith and Greg 1. This is #3/3 in a string today - all with some relationship to the MacDougall article). Not sure of the etiquette here as Keith was only addressing Greg and myself. But Greg responded to the full list and I think/hope Keith would like that I do the same. Keith has talked of his proposed low-cost electricity approach earlier on this list.
2. As background, readers interested in Keith’s electricity production views should look at material at https://docs.google.com/file/d/1PHkFACumTHyfMPOfIDhAY46vPe_mt8zNmy3i2ZsOnHgqZqpGuMpSh3JaJsCO/edit I also found a video covering the same. 3. I am pretty sure that Keith is one of the world experts on this solar satellite topic. He certainly has had a long history of various space-oriented activities. 4. See also two responses below. On Dec 20, 2013, at 11:13 AM, Keith Henson <[email protected]> wrote: > On Fri, Dec 20, 2013 at 8:20 AM, Ronal W. Larson > <[email protected]> wrote: >> Keith cc Greg >> >> I appreciate your enthusiasm for the solar satellite approach, but I have >> my hands more than full with CDR (and specifically biochar). > > What you really need is a way to turn off the current flow of CO2 into > the atmosphere. *Then* biochar or other ways to lower the CO2 have a > chance to work. But that's not going to happen as long as people need > energy to stay alive unless there is a way to replace the energy from > fossil fuels. It's the reason Hansen and the rest of them have > recognized nuclear energy. That will work if you are willing to put > up with a meltdown a year. RWL1. Readers will find that Keith’s approach is quite expensive (many trillions of $) and not likely ready soon. The above site shows a new lower cost way to put hardware in space. My view is that today's renewables can do the job at an acceptable cost - but I wish Keith luck if he can do the fossil fuel replacement job cheaper. I concur on his statements about nuclear - which I believe has no or small connection to geoengineering. Keith has previously proposed a way to make a fuel starting with CO2 and his low cost electricity. Again not a “Geo” topic -but maybe someone can offer other approaches on either the CDR or fossil replacement tasks? > >> What was the >> reason the Japanese dropped their program? > > I don't know, but it really doesn't matter. The program they were > working on would not lead to displacing fossil fuels. The > Skylon/laser propulsion/power satellite approach *might*. > > I calculated how much energy it would take to capture and safely > sequester 100 ppm of CO2. Have you run this calculation? [RWL: The first answer is that biochar doesn’t require ANY energy - as pyrolysis is exothermic. But assuming Keith wants to know how energy and char work together, I can say they are NOT partners; more of one means less of the other (biochar is a partner with soil improvement). But if half of the initial carbon produces energy (and released CO2), then 100 ppm of CO2 requires about 400 Gt C to be put in the ground (we have had other dialog on this number). The energy content of the other 400 Gt C is valued at about 30 GJ/tonne C. (of course not all useful). Thus the theoretical available energy is about 12,000 E18 Joules. Hopefully, we can get started soon enough that we need less than 100 ppm. Hopefully there will be a suite of CDR approaches, that will be using PV, wind, hydro, geothermal (and some non-biochar biomass) What is your own calculation on “how much energy it would take”? (I presume all of an opposite sign?) Ron > > (The next addressed today to Greg and myself, with one response each from > Greg and myself) >> >> >> On Dec 20, 2013, at 12:05 AM, Keith Henson <[email protected]> wrote: >> >> Would you be interested in an engineering proposal to end the use of >> fossil fuels? >> >> Warning, it does so by substituting a cheaper energy source. >> >> Keith Henson >> >> On Thu, Dec 19, 2013 at 10:33 AM, Greg Rau <[email protected]> wrote: >> >> Delayed response from me also. Just saw a brief review of this paper in my <snipped - to save space; I think all repeated earlier today> -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
