[geo] Re: New report(s) on carbon dioxide removal
. The question for Duncan, Dr. Zeng and others on this list are whether these out-year CO2-climate benefits of Biochar should be included ? Or should all NET computations have the same (one year) time regime. 6. Second, whether non-CO2-related, but clear economic benefits (like increased multi-year crop yield and increased multi-year farmer income) should somehow enter into the dialog. For many in the Biochar research arena this is their main focus; NETs (carbon-negativity) are a distant second in their thinking. Increased soil productivity might obviate the need for carbon credits entirely (as was the case for the Amazonian Indians centuries ago.) This is somewhat like saying that it is important for BECCS proponents that there is an income from (carbon-neutral) electricity sales, but in this final NET (carbon-negativity) question, I am going one step further - carbon-neutrality is not involved. 7. It is my impression that Duncan has not included these last two issues when calculating a Biochar price in the curves of his Figures 5 and 7. Surprisingly, Biochar also doesn't appear in the economics of Table 10 - maybe because of these analytical hurdles. I have other questions on the potential magnitude of the Biochar resource, which I think should be larger than the other biomass options, but that is a different topic I will raise separately with Duncan. 8. Despite my questioning here, I think Duncan has done a better job than anyone else of comparing the NET options. I am only trying to make clear the process, and the assumptions for his second edition. If carbon-neutral (energy), out-year, and non-CO2 topics are to be either included or excluded from NET analyses, I feel it should be made clear why. Thoughts? Ron - Original Message - From: Ning Zeng z...@atmos.umd.edu To: geoengineering geoengineering@googlegroups.com Sent: Wednesday, September 28, 2011 7:21:48 AM Subject: [geo] Re: New report(s) on carbon dioxide removal Talking about wood products for carbon sequestration, I don't know if you have seen this report from the Wilderness Society, perhaps the most in-depth I've seen? -Ning http://wilderness.org/files/Wood-Products-and-Carbon-Storage.pdf On Sep 27, 7:55 am, Duncan McLaren duncan.p.mcla...@gmail.com wrote: Thanks for your feedback. It's great to see more detailed work ongoing, and I look forward to reading your paper. Hopefully I will get the chance to use it to update my report. I agree that sustainable forestry has a role in a package of NETs, but whether WHS is the best option for some or all of the accumulated carbon is an open question for me still. Comentators above have argued for BECCS and biochar. Personally I have a soft spot for timber use in construction (even if the store is relatively shortlived). I agree that there are environmental impacts from most if not all NETs, and hadn't intended to imply that forestry-related approaches were particularly bad, simply to highlight that current forestry techniques are not always sustainable (or ethical for that matter), and expanding conventional approaches to plantation forestry, for example, could be counterproductive, even in carbon terms. Best wishes Duncan On Sep 25, 4:37 pm, Ning Zeng z...@atmos.umd.edu wrote: Hello Duncan: I enjoyed reading through your very nice analysis of NETs over the weekend. I agree with Oliver Tickell's comment that we need knowledge, not conjecture. I have been researching on the wood burial idea which has even less research compared to many others. We have a paper that is in review at Climatic Change, which brings more information on wood burial's (we now call it Wood Harvest and Storage or WHS) harvest potential, and more information is on the way on cost and storage and other practical considerations. The abstract of the paper is below. It is relevant to some key factors you discussed in your report, including: 1. We use GtC, while you use GtCO2, so that the estimate of Zeng (2008) of 10 GtC potential is really 37 GtC/y. However, that is just a theoretical potential based on coarse wood production rate of all world's forests. In this new paper (Zeng et al. 2011), we consider many practical constraints including land use and conservation needs, and we arrive at a range of 1-3 GtC/y (4-10 GtCO2/y). 2. This new paper also shows the area of forest needed in order to accomplish these sequestration goals. At our low value of 1GtC/y, it requires 800 Mha forest land with a (modest) harvest intensity of 1 tC/ ha/y, a much lower rate than typically assumed bioenergy crop harvest rate. The amount of biomass (2Gt dry biomass) involved is equivalent to the current worldwide forest harvest. So this is definitely not business-as-usual, but a leap for forestry
[geo] Re: New report(s) on carbon dioxide removal
Thanks John Please keep me in the loop on your thoughts on combining biochar and soil mineralisation with rock dust. We need all the sensible ideas we can get. Regarding the potential benefits of biochar, I tried to include potential benefits for any technique where they were suggested or reported, under the heading of 'side effects'. And in the discussion I suggested that where positive side effects could be demonstrated it might make a technique more attractive. This may well apply to biochar (although the benefits have yet to be consistently demonstrated and quantified - as far as I could tell), and I particularly suggest that biochar might be the optimum route for sustainable biomass where decentralised energy is needed, and where geological stores/ CO2 pipelines are far distant, or exhausted. Given a limit to sustainable biomass production, and competition for theat biomass: I agree we need to use multi-criteria assessment to decide the optimum distribution of use. However given such a limit, then the net carbon benefit might have to be weighted highly in any such assessment. I also broadly agree with you regarding the near term need for NETs, though my estimates would suggest that getting back to 350 anytime before the end of the century will be a push. Best wishes Duncan On Sep 21, 11:53 pm, John Nissen johnnissen2...@gmail.com wrote: 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 duncan.p.mcla...@gmail.com 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 at https://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 -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
[geo] Re: New report(s) on carbon dioxide removal
Talking about wood products for carbon sequestration, I don't know if you have seen this report from the Wilderness Society, perhaps the most in-depth I've seen? -Ning http://wilderness.org/files/Wood-Products-and-Carbon-Storage.pdf On Sep 27, 7:55 am, Duncan McLaren duncan.p.mcla...@gmail.com wrote: Thanks for your feedback. It's great to see more detailed work ongoing, and I look forward to reading your paper. Hopefully I will get the chance to use it to update my report. I agree that sustainable forestry has a role in a package of NETs, but whether WHS is the best option for some or all of the accumulated carbon is an open question for me still. Comentators above have argued for BECCS and biochar. Personally I have a soft spot for timber use in construction (even if the store is relatively shortlived). I agree that there are environmental impacts from most if not all NETs, and hadn't intended to imply that forestry-related approaches were particularly bad, simply to highlight that current forestry techniques are not always sustainable (or ethical for that matter), and expanding conventional approaches to plantation forestry, for example, could be counterproductive, even in carbon terms. Best wishes Duncan On Sep 25, 4:37 pm, Ning Zeng z...@atmos.umd.edu wrote: Hello Duncan: I enjoyed reading through your very nice analysis of NETs over the weekend. I agree with Oliver Tickell's comment that we need knowledge, not conjecture. I have been researching on the wood burial idea which has even less research compared to many others. We have a paper that is in review at Climatic Change, which brings more information on wood burial's (we now call it Wood Harvest and Storage or WHS) harvest potential, and more information is on the way on cost and storage and other practical considerations. The abstract of the paper is below. It is relevant to some key factors you discussed in your report, including: 1. We use GtC, while you use GtCO2, so that the estimate of Zeng (2008) of 10 GtC potential is really 37 GtC/y. However, that is just a theoretical potential based on coarse wood production rate of all world's forests. In this new paper (Zeng et al. 2011), we consider many practical constraints including land use and conservation needs, and we arrive at a range of 1-3 GtC/y (4-10 GtCO2/y). 2. This new paper also shows the area of forest needed in order to accomplish these sequestration goals. At our low value of 1GtC/y, it requires 800 Mha forest land with a (modest) harvest intensity of 1 tC/ ha/y, a much lower rate than typically assumed bioenergy crop harvest rate. The amount of biomass (2Gt dry biomass) involved is equivalent to the current worldwide forest harvest. So this is definitely not business-as-usual, but a leap for forestry. 3. The cost estimate of Zeng (2008) of $14/tCO2 was based on cost of harvesting. If including storage (mostly in situ around harvest landing site to minimize transportation cost), it will probably double to $30/tCO2. Adding other unforseen cost, bearing in mind the observation that real-world implementation often tends to be more expensive, I'd wave my hand (before realistic demo project) to put the cost at about $50/tCO2. I think this is actually what you used in the cost/potential plot (Fig. 7). 4. I thought it's a bit unfair to apply environmental impact to wood burial, while not to other methods. All these have major environmental issues to consider, but my feeling is that sustainable forestry, we actually know better how to do it right. Best Regards! -Ning Zeng Ecological carbon sequestration via wood harvest and storage: An assessment of its practical harvest potential Ning Zeng, Anthony King, Ben Zaitchik, Stan Wullschleger, Jay Gregg, Shaoqiang Wang, Dan Kirk-Davidoff A carbon sequestration strategy has recently been proposed in which a forest is sustainably managed to optimal carbon productivity, and a fraction of the wood is selectively harvested and stored to prevent decomposition. The forest serves as a ‘carbon scrubber’ or ‘carbon remover’ that provides continuous sequestration (negative emissions). The stored wood is a semi-permanent carbon sink, but also serves as a ‘biomass/bioenergy reserve’ that could be utilized in the future. Earlier estimates of the theoretical potential of wood harvest and storage (WHS) were 10 ± 5 GtC y-1. Starting from this physical limit, here we apply a number of practical constraints: (1) land not available due to agriculture; (2) forest set aside as protected areas, assuming 50% in the tropics and 20% in temperate and boreal forests; (3) forests difficult to access due to steep terrain; (4) wood use for other purposes such as timber and paper. This ‘top-down’ approach yields a WHS potential 2.8 GtC y-1. Alternatively, a ‘bottom-up’ approach, assuming more efficient wood use without
Re: [geo] Re: New report(s) on carbon dioxide removal
only trying to make clear the process, and the assumptions for his second edition. If carbon-neutral (energy), out-year, and non-CO2 topics are to be either included or excluded from NET analyses, I feel it should be made clear why. Thoughts? Ron - Original Message - From: Ning Zeng z...@atmos.umd.edu To: geoengineering geoengineering@googlegroups.com Sent: Wednesday, September 28, 2011 7:21:48 AM Subject: [geo] Re: New report(s) on carbon dioxide removal Talking about wood products for carbon sequestration, I don't know if you have seen this report from the Wilderness Society, perhaps the most in-depth I've seen? -Ning http://wilderness.org/files/Wood-Products-and-Carbon-Storage.pdf On Sep 27, 7:55 am, Duncan McLaren duncan.p.mcla...@gmail.com wrote: Thanks for your feedback. It's great to see more detailed work ongoing, and I look forward to reading your paper. Hopefully I will get the chance to use it to update my report. I agree that sustainable forestry has a role in a package of NETs, but whether WHS is the best option for some or all of the accumulated carbon is an open question for me still. Comentators above have argued for BECCS and biochar. Personally I have a soft spot for timber use in construction (even if the store is relatively shortlived). I agree that there are environmental impacts from most if not all NETs, and hadn't intended to imply that forestry-related approaches were particularly bad, simply to highlight that current forestry techniques are not always sustainable (or ethical for that matter), and expanding conventional approaches to plantation forestry, for example, could be counterproductive, even in carbon terms. Best wishes Duncan On Sep 25, 4:37 pm, Ning Zeng z...@atmos.umd.edu wrote: Hello Duncan: I enjoyed reading through your very nice analysis of NETs over the weekend. I agree with Oliver Tickell's comment that we need knowledge, not conjecture. I have been researching on the wood burial idea which has even less research compared to many others. We have a paper that is in review at Climatic Change, which brings more information on wood burial's (we now call it Wood Harvest and Storage or WHS) harvest potential, and more information is on the way on cost and storage and other practical considerations. The abstract of the paper is below. It is relevant to some key factors you discussed in your report, including: 1. We use GtC, while you use GtCO2, so that the estimate of Zeng (2008) of 10 GtC potential is really 37 GtC/y. However, that is just a theoretical potential based on coarse wood production rate of all world's forests. In this new paper (Zeng et al. 2011), we consider many practical constraints including land use and conservation needs, and we arrive at a range of 1-3 GtC/y (4-10 GtCO2/y). 2. This new paper also shows the area of forest needed in order to accomplish these sequestration goals. At our low value of 1GtC/y, it requires 800 Mha forest land with a (modest) harvest intensity of 1 tC/ ha/y, a much lower rate than typically assumed bioenergy crop harvest rate. The amount of biomass (2Gt dry biomass) involved is equivalent to the current worldwide forest harvest. So this is definitely not business-as-usual, but a leap for forestry. 3. The cost estimate of Zeng (2008) of $14/tCO2 was based on cost of harvesting. If including storage (mostly in situ around harvest landing site to minimize transportation cost), it will probably double to $30/tCO2. Adding other unforseen cost, bearing in mind the observation that real-world implementation often tends to be more expensive, I'd wave my hand (before realistic demo project) to put the cost at about $50/tCO2. I think this is actually what you used in the cost/potential plot (Fig. 7). 4. I thought it's a bit unfair to apply environmental impact to wood burial, while not to other methods. All these have major environmental issues to consider, but my feeling is that sustainable forestry, we actually know better how to do it right. Best Regards! -Ning Zeng Ecological carbon sequestration via wood harvest and storage: An assessment of its practical harvest potential Ning Zeng, Anthony King, Ben Zaitchik, Stan Wullschleger, Jay Gregg, Shaoqiang Wang, Dan Kirk-Davidoff A carbon sequestration strategy has recently been proposed in which a forest is sustainably managed to optimal carbon productivity, and a fraction of the wood is selectively harvested and stored to prevent decomposition. The forest serves as a ‘carbon scrubber’ or ‘carbon remover’ that provides continuous sequestration (negative emissions). The stored wood is a semi-permanent carbon sink, but also serves as a ‘biomass/bioenergy reserve’ that could be utilized in the future. Earlier estimates of the theoretical
[geo] Re: New report(s) on carbon dioxide removal
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, rongretlar...@comcast.net 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: rongretlar...@comcast.net To: duncan p mclaren duncan.p.mcla...@gmail.com, biochar-pol...@yahoogroups.com Cc: John Nissen j...@cloudworld.co.uk, Oliver Tickell oliver.tick...@kyoto2.org, geoengineering geoengineering@googlegroups.com, johnnissen2...@gmail.com 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 johnnissen2...@gmail.com To: duncan p mclaren duncan.p.mcla...@gmail.com Cc: John Nissen j...@cloudworld.co.uk, Ron Larson rongretlar...@comcast.net, Oliver Tickell oliver.tick...@kyoto2.org, biochar-pol...@yahoogroups.com, geoengineering geoengineering@googlegroups.com 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
[geo] Re: New report(s) on carbon dioxide removal
centuries ago.) This is somewhat like saying that it is important for BECCS proponents that there is an income from (carbon-neutral) electricity sales, but in this final NET (carbon-negativity) question, I am going one step further - carbon-neutrality is not involved. 7. It is my impression that Duncan has not included these last two issues when calculating a Biochar price in the curves of his Figures 5 and 7. Surprisingly, Biochar also doesn't appear in the economics of Table 10 - maybe because of these analytical hurdles. I have other questions on the potential magnitude of the Biochar resource, which I think should be larger than the other biomass options, but that is a different topic I will raise separately with Duncan. 8. Despite my questioning here, I think Duncan has done a better job than anyone else of comparing the NET options. I am only trying to make clear the process, and the assumptions for his second edition. If carbon-neutral (energy), out-year, and non-CO2 topics are to be either included or excluded from NET analyses, I feel it should be made clear why. Thoughts? Ron - Original Message - From: Ning Zeng z...@atmos.umd.edu To: geoengineering geoengineering@googlegroups.com Sent: Wednesday, September 28, 2011 7:21:48 AM Subject: [geo] Re: New report(s) on carbon dioxide removal Talking about wood products for carbon sequestration, I don't know if you have seen this report from the Wilderness Society, perhaps the most in-depth I've seen? -Ning http://wilderness.org/files/Wood-Products-and-Carbon-Storage.pdf On Sep 27, 7:55 am, Duncan McLaren duncan.p.mcla...@gmail.com wrote: Thanks for your feedback. It's great to see more detailed work ongoing, and I look forward to reading your paper. Hopefully I will get the chance to use it to update my report. I agree that sustainable forestry has a role in a package of NETs, but whether WHS is the best option for some or all of the accumulated carbon is an open question for me still. Comentators above have argued for BECCS and biochar. Personally I have a soft spot for timber use in construction (even if the store is relatively shortlived). I agree that there are environmental impacts from most if not all NETs, and hadn't intended to imply that forestry-related approaches were particularly bad, simply to highlight that current forestry techniques are not always sustainable (or ethical for that matter), and expanding conventional approaches to plantation forestry, for example, could be counterproductive, even in carbon terms. Best wishes Duncan On Sep 25, 4:37 pm, Ning Zeng z...@atmos.umd.edu wrote: Hello Duncan: I enjoyed reading through your very nice analysis of NETs over the weekend. I agree with Oliver Tickell's comment that we need knowledge, not conjecture. I have been researching on the wood burial idea which has even less research compared to many others. We have a paper that is in review at Climatic Change, which brings more information on wood burial's (we now call it Wood Harvest and Storage or WHS) harvest potential, and more information is on the way on cost and storage and other practical considerations. The abstract of the paper is below. It is relevant to some key factors you discussed in your report, including: 1. We use GtC, while you use GtCO2, so that the estimate of Zeng (2008) of 10 GtC potential is really 37 GtC/y. However, that is just a theoretical potential based on coarse wood production rate of all world's forests. In this new paper (Zeng et al. 2011), we consider many practical constraints including land use and conservation needs, and we arrive at a range of 1-3 GtC/y (4-10 GtCO2/y). 2. This new paper also shows the area of forest needed in order to accomplish these sequestration goals. At our low value of 1GtC/y, it requires 800 Mha forest land with a (modest) harvest intensity of 1 tC/ ha/y, a much lower rate than typically assumed bioenergy crop harvest rate. The amount of biomass (2Gt dry biomass) involved is equivalent to the current worldwide forest harvest. So this is definitely not business-as-usual, but a leap for forestry. 3. The cost estimate of Zeng (2008) of $14/tCO2 was based on cost of harvesting. If including storage (mostly in situ around harvest landing site to minimize transportation cost), it will probably double to $30/tCO2. Adding other unforseen cost, bearing in mind the observation that real-world implementation often tends to be more expensive, I'd wave my hand (before realistic demo project) to put the cost at about $50/tCO2. I think this is actually what you used in the cost/potential plot (Fig. 7). 4. I thought it's a bit unfair to apply environmental impact to wood burial, while not to other methods. All these have major environmental issues to consider, but my feeling
[geo] Re: New report(s) on carbon dioxide removal
Thanks for your feedback. It's great to see more detailed work ongoing, and I look forward to reading your paper. Hopefully I will get the chance to use it to update my report. I agree that sustainable forestry has a role in a package of NETs, but whether WHS is the best option for some or all of the accumulated carbon is an open question for me still. Comentators above have argued for BECCS and biochar. Personally I have a soft spot for timber use in construction (even if the store is relatively shortlived). I agree that there are environmental impacts from most if not all NETs, and hadn't intended to imply that forestry-related approaches were particularly bad, simply to highlight that current forestry techniques are not always sustainable (or ethical for that matter), and expanding conventional approaches to plantation forestry, for example, could be counterproductive, even in carbon terms. Best wishes Duncan On Sep 25, 4:37 pm, Ning Zeng z...@atmos.umd.edu wrote: Hello Duncan: I enjoyed reading through your very nice analysis of NETs over the weekend. I agree with Oliver Tickell's comment that we need knowledge, not conjecture. I have been researching on the wood burial idea which has even less research compared to many others. We have a paper that is in review at Climatic Change, which brings more information on wood burial's (we now call it Wood Harvest and Storage or WHS) harvest potential, and more information is on the way on cost and storage and other practical considerations. The abstract of the paper is below. It is relevant to some key factors you discussed in your report, including: 1. We use GtC, while you use GtCO2, so that the estimate of Zeng (2008) of 10 GtC potential is really 37 GtC/y. However, that is just a theoretical potential based on coarse wood production rate of all world's forests. In this new paper (Zeng et al. 2011), we consider many practical constraints including land use and conservation needs, and we arrive at a range of 1-3 GtC/y (4-10 GtCO2/y). 2. This new paper also shows the area of forest needed in order to accomplish these sequestration goals. At our low value of 1GtC/y, it requires 800 Mha forest land with a (modest) harvest intensity of 1 tC/ ha/y, a much lower rate than typically assumed bioenergy crop harvest rate. The amount of biomass (2Gt dry biomass) involved is equivalent to the current worldwide forest harvest. So this is definitely not business-as-usual, but a leap for forestry. 3. The cost estimate of Zeng (2008) of $14/tCO2 was based on cost of harvesting. If including storage (mostly in situ around harvest landing site to minimize transportation cost), it will probably double to $30/tCO2. Adding other unforseen cost, bearing in mind the observation that real-world implementation often tends to be more expensive, I'd wave my hand (before realistic demo project) to put the cost at about $50/tCO2. I think this is actually what you used in the cost/potential plot (Fig. 7). 4. I thought it's a bit unfair to apply environmental impact to wood burial, while not to other methods. All these have major environmental issues to consider, but my feeling is that sustainable forestry, we actually know better how to do it right. Best Regards! -Ning Zeng Ecological carbon sequestration via wood harvest and storage: An assessment of its practical harvest potential Ning Zeng, Anthony King, Ben Zaitchik, Stan Wullschleger, Jay Gregg, Shaoqiang Wang, Dan Kirk-Davidoff A carbon sequestration strategy has recently been proposed in which a forest is sustainably managed to optimal carbon productivity, and a fraction of the wood is selectively harvested and stored to prevent decomposition. The forest serves as a ‘carbon scrubber’ or ‘carbon remover’ that provides continuous sequestration (negative emissions). The stored wood is a semi-permanent carbon sink, but also serves as a ‘biomass/bioenergy reserve’ that could be utilized in the future. Earlier estimates of the theoretical potential of wood harvest and storage (WHS) were 10 ± 5 GtC y-1. Starting from this physical limit, here we apply a number of practical constraints: (1) land not available due to agriculture; (2) forest set aside as protected areas, assuming 50% in the tropics and 20% in temperate and boreal forests; (3) forests difficult to access due to steep terrain; (4) wood use for other purposes such as timber and paper. This ‘top-down’ approach yields a WHS potential 2.8 GtC y-1. Alternatively, a ‘bottom-up’ approach, assuming more efficient wood use without increasing harvest, finds 0.1-0.5 GtC y-1 available for carbon sequestration. We suggest a range of 1-3 GtC y-1 carbon sequestration potential if major investment is made to expand managed forests and/or to increase management intensity. The implementation of such a scheme at our estimated lower value of 1 GtC y-1 would imply a doubling of the current world wood harvest rate.
[geo] Re: New report(s) on carbon dioxide removal
Thanks Henrik fro these comments. I'm very pleased that experts in particular techniques are looking at my report. And I'm not going to be surprised if everyone feels that I haven't done justice to their particular topic. However I must refute the implication that I have taken things 'out-of- context'. For example Biorecro's Swedish numbers for example are clearly described as such, not as globally representative. I'm sorry if you read my caveat regarding data as implying that my summary graphics and tables only included estimates from other sources. That was not intended to be my meaning. I wanted to stress that while I had made efforts and judgements to allow comparison, I remain very nervous about how valid such comparison could be, given the range of sources and assumptions. I did not, and do not want readers saying technology A will cost x% less than technology B, so is therefore obviously preferable, especially in those cases where x is small. I think one of the main lessons in the report is that practical and sustainability constraints must drive how we plan and deploy a package of NETs, not costs per se. I welcome the chance to elaborate on why I do not accept the more optimistic cost estimates for many technologies, not just BECCS. I must stress again that the cost figures in particular should be treated with caution (and I wish other authors would do so more often with their estimates ...). However in the case of BECCS there is more material (albeit rarely with clear assumptions set out), so it was possible to come up with amended estimates which I believe are plausible. For some of the other techniques the best I could do was describe an estimated cost as 'optimistic' or 'realistic'. I think BECCS costs cited by yourself, Ecofys and others are potentially very optimistic for several reasons. Sometimes estimates in the literature are simply costs per ton CO2 captured or stored. They are therefore lower than real costs per tonne of net negative emission (NE). In other places advocates of BECCS argue that it will be cheap because it can sell energy. But I have treated it as a cost imposed on a stand-alone bioenergy system. Furthermore I could not typically identify assumptions regarding the likely future costs of CCS on fossil fuels, and learning rates on CCS and on application of CCS to bioenergy. However it would appear that most assume that CCS will become commercially viable by 2030, and thus the cost of BECCS is pretty well only the additional cost of modifying and applying the system to bioenergy. However, the future cost evolution of CCS is still highly debatable. I cite sources suggesting that current and future CCS costs estimates are likely to be underestimates, and that learning rates may be as low as zero. Even if learning rates are positive, the impatc on costs depends on deployment, which I conclude may be practically restricted by non- economic factors, again potentially raising future costs above the estimates elsewhere. Applying all these factors as far as practical to the range of costs I found in the literature (see p.43) gave me a cost range for BECCS from around $75 to over $300 per ton NE. I concluded that a range of $100-150 per ton NE was plausible and chose to use the higher figure in the summary and graphics. Of course there are a whole range of judgements wrapped up here and indeed a wide range of techniques within BECCS, so clearly a more sophisticated analysis could be undertaken. You also quibble with the TRL rating I suggest for BECCS. You have a point in comparison with wet DAC as far as BECCS on ethanol is concerned, but I'm not so sure as a general rating for BECCS. I would also note that the recent GAO Technology Assessment also rates BECCS and wet DAC as exactly the same maturity ... but they give them both a rating of just 2! Thanks again for raising these issues, and I look forward to continuing a dialogue. Best regards Duncan On Sep 22, 1:27 pm, Henrik Karlsson henrik.karls...@biorecro.se wrote: Hi Duncan, Thank you for your time and effort into this difficult field. I believe that this report and similar initiatives are very valuable, and must be supported. In my opinion, you have also made an important pioneering effort into cost and potential comparisons of various NETs, which I hope you will be able to carry on in greater detail. Unfortunately, I do not support the methods used to process the data in your report, which I believe have led to conclusions that are not supported in your sources. I can only speak for BECCS, the area of my expertise, but I know that some of the statements on BECCS in this report are not fsupported by the sources available. Additionally, quotes from reports which I have been lead author on (Karlsson 2010 and Karlsson 2011) have been detached from their context. Swedish numbers from (Karlsson 2010) are used in the report to represent a global context, which they are not suitable for. Similarly, the
[geo] Re: New report(s) on carbon dioxide removal
For those struggling to find it, the FOE summary version link is http://www.foe.co.uk/resource/reports/negatonnes.pdf On Sep 21, 1:11 pm, Duncan McLaren duncan.p.mcla...@gmail.com 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 -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
