Thanks for these comments Ron I am a fan of Rockstrom's 'planetary boundaries' approach, as it provides a better scientific basis for work on environmental constraints that anything before (I worked on 'environmental space' in the 1990s for example).
As I noted in my reply to John, benefits are included in my assessment (under side-effects) - but I couldn't find much on verified or demonstrated benefits from biomass. I'd be delighted if you could point me at material (especially peer reviewed stuff) which sets out the benefits you mention in more detail. Thanks Duncan On Sep 23, 6:58 am, [email protected] wrote: > Lists, Duncan McLaren, John Nissen and other ccs > > 1. I did a lot of reading today on Duncan's "NET-comparison" report > identified below. But I am not ready to give comments as I am still not yet > finished. The delay is in part because I read pretty carefully one more > (shorter - 50 page) similar report by Duncan - and recommend it as it is > quite policy oriented - athttp://www.foe.co.uk/resource/reports/negatonnes.pdf > > 2. However as a progress report, I can say I now agree fully with John Nissen > - that I hope Duncan can add a tabulation of allied benefits for each of the > NETS. Of course, many of us know Biochar will come out further ahead with > that addition to NET-scoring. > > 3. I decided to send this partial response today mainly because a Denver > friend today sent me information on a program that has identified a list of > nine major global problems. The full description of these nine areas, of > course headed by "climate", can be found at: > > http://www.stockholmresilience.org/research/researchnews/planetarybou... > andhttp://www.stockholmresilience.org/download/18.8615c78125078c8d338000... > > 4. The full problem list (in short form) is: > > 1. * climate - 350 ppm > 2. ozone > 3. ocean acidification (aragonite concentration ratio) > 4. freshwater use > 5. land use > 6. * biological diversity > 7. * N/P cycles > 8. chemical pollution > 9. aerosol loading > > 5. It was a surprise to me that Biochar can have an impact in ALL nine areas. > It is that sort of information about Biochar that John Nissen, myself, and > all Biochar advocates are hoping Mr. McLaren will add to his next version > (and this nine is only a partial list). > > Ron > > > > > > > > ----- Original Message ----- > From: [email protected] > To: "duncan p mclaren" <[email protected]>, > [email protected] > Cc: "John Nissen" <[email protected]>, "Oliver Tickell" > <[email protected]>, "geoengineering" > <[email protected]>, [email protected] > Sent: Wednesday, September 21, 2011 11:56:15 PM > Subject: Re: [geo] New report(s) on carbon dioxide removal > > Duncan and ccs > > 1. First thanks to John Nissen for forwarding your note to several groups > that will take your new report on CDR (what you are terming "NET") very > seriously. > > 2. Below, I have included your main section 6.1.5 on Biochar (about 5 pages) > - so that others will have an easier time copying and replying to your > request (below) for comments. > > 3. I will withhold most comment until I have had a chance to read the whole > report. However, like John, I recognize that this entailed a great deal of > work and I am unaware of any other more complete comparison of these > "CDR-NET" technologies that most reading this regard as highly important and > under-funded. Thanks for taking this task on. The main major Biochar resource > that I find missing is the website:www.biochar-international.org > > Ron > > see more pages below > ----- Original Message ----- > From: "John Nissen" <[email protected]> > To: "duncan p mclaren" <[email protected]> > Cc: "John Nissen" <[email protected]>, "Ron Larson" > <[email protected]>, "Oliver Tickell" <[email protected]>, > [email protected], "geoengineering" > <[email protected]> > Sent: Wednesday, September 21, 2011 3:53:18 PM > Subject: Re: [geo] New report(s) on carbon dioxide removal > > Hi Duncan, > > Thank you for your tremendous effort to describe all the available CDR/NET > technologies together, in a comprehensive way such to allow a comparison. > > I've been discussing biochar and rock crushing with Ron Larson and Oliver > Tickell; we concluded that there was scope for a combined method, which could > be scaled up to remove many gigatonnes of carbon per year at low cost. (We've > used weight of carbon rather than CO2 in our calculations.) > > I think you should have a separate column for benefits, because biochar has > several: it improves soil, reduces need for fertiliser (thus avoids > considerable emissions), reduces water requirements, and is applicable in > poorer countries for improved, productive and profitable farming. > > It is now recognised that ocean acidification could be far more serious and > more urgent than hitherto suggested, such that we'd need CDR to get the > atmospheric level of CO2 below 350 ppm within twenty or thirty years. For the > first ten years, we'd have to build up CDR such as to cancel out global CO2 > emissions. Then we'd have to ramp up CDR a bit further to actually reduce the > CO2 level. I would like to see biochar take a significant role - but it would > require education and infrastructure projects to mobilise farmers worldwide. > > Cheers, > > John > > -- > > On Wed, Sep 21, 2011 at 12:11 PM, Duncan McLaren < [email protected] > > wrote: > > Group members may find my assessment of negative emissions > technologies (NETs) of interest. > > The full report runs to about 100 pages, and can be found > athttps://sites.google.com/site/mclarenerc/research/negative-emissions-... > > A summary version written for Friends of the Earth (England, Wales and > NI) will be published online later today. > > The assessment covers a wide range of NETs, but not SRM techniques. It > considers capacity, cost, side effects, constraints, technical > readiness, accountability and more for about 30 options. > > I'd be delighted to get feedback and comments. > > regards > Duncan > > RWL: Below is the full section (6.1.5) on Biochar. (There are other important > comparative tables, also) > > The following is a Word version of the Biochar section in the recent report > on “NETs”, authored by Duncan McLaren. The full report is at: > > https://sites.google.com/site/mclarenerc/research/negative-emissions-... > > 6.1.5 Biochar > > Carbon can be stored for long periods, perhaps thousands of years in the form > of charcoal in soils. > > Biochar takes advantage of this by partially combusting biomass in an > oxygen-depleted > > environment to produce a carbon rich char and some useful energy. Most > current research focuses > > on pyrolysis of biomass, which produces energy mainly in the form of liquid > fuel and some > > synthetic or syngas. Gasification produces mainly syngas and limited amounts > of char and ash. > > There has been a surge of enthusiasm for biochar, which has led to optimistic > assessments of > > potential based on assumptions of high availability of sustainable biomass, > potentially from > > dedicated plantations. > > Advocates of biochar state that the process could generate a potential carbon > sink of 3.7 GtC-CO2 > > pa by 2030 (Shackley and Sohi, 2011) rising to 20 to 35 Gt CO2 pa by 2100 > (Lehmann et al., 2006). > > For our purposes, the latter estimate is considered excessive (for > sustainability reasons), which the > > former may well also be optimistic in the technical rate of deployment > implied. > > Lehman et al (2006)'s estimate is based on analysis which concluded that > bio-fuel production using > > modern biomass could produce a biochar by-product through pyrolysis that > results in 30.6 kg C > > being sequestered for every GJ of energy produced. They then calculated that > by 2100, biochar > > sequestration could amount to 5.5 – 9.5Gt C yr if renewable energy demand was > met through > > pyrolysis. > > Lenton and Vaughan (2009) also attempted to calculate a maximum contribution. > They quantified > > Page 30 /103 > > the climate cooling effectiveness of biochar in terms of radiative forcing > and, assuming 100% > > retention of char carbon in the soil in the first 100 years, they calculated > a reduction in atmospheric > > carbon of up to 81Gt CO2 (equivalent to a reduction of 10ppm CO2) by 2050. > Continuing the trend > > forward, they predicted 290Gt CO2 by 2100. This was based on a maximum rate > of 11.5Gt CO2 pa > > by 2100. Lenton (2011) cites further estimates of 4.4Gt CO2 in 2035 and 11.5 > in 2100, or based on > > existing biomass flows only, of 2.8-3.2Gt CO2 pa. > > Biochar > > Category: Mineral, indirect. > > Description : Storing partially combusted organic matter (char) in soil by > burial, preventing the return of > > biotic carbon to the atmosphere via decomposition. The char can be created > from organic matter by > > pyrolysis or gasification, either of which provides some bioenergy (Shackley > & Sohi, 2011). > > Capacity / Scalability : There are a wide range of published estimates, with > plausible global maximum > > estimates at around 1Gt-CO2 pa (based on Woolf 2010). The technology itself > is fairly simple and scalable, > > and can use a variety of inputs including biowastes, but there are limits to > feedstocks and locations. UK > > estimates range from 4-48Mt CO2 pa by 2030 (Shackley & Sohi, 2011, McGlashan > et al, 2010). > > Limiting factors : As with all indirect techniques, biochar would be limited > by the availability of > > sustainable biomass feedstuffs. There may also be limits to the application > of char to agricultural land, > > especially char from wastes such as sewage sludge, as well as overall limits > on total char storage in soil and > > practical application rates. In practice biochar would face competition from > other uses for feedstuffs, > > reducing capacity below the theoretical maximum. > > Side effects : Beneficial impacts on soil fertility have been claimed, but > have not been consistently > > demonstrated. Possible health impacts from erosion and wind dispersal of > carcinogenic carbonised dust > > have been noted, and impacts from interactions with herbicides are being > researched. > > Estimated cost : Uncertain as yet, but subject to feedstock being produced at > <$100/oven dried ton the > > abatement cost is estimated as around $30 to $40/t-CO2 (Shackley & Sohi, > 2011). > > Current status (TRL) : Theoretically demonstrated. Small scale field trials > are ongoing, both in UK and > > elsewhere (TRL 4-6). Significant commercial effort is emerging, with a > particular focus on use of > > biowastes as a route to commercialisation. > > Expected development : Fairly rapid. > > ... > > read more » -- 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.
