BECCS is qualitatively interesting, sure, and it makes more sense to me than air capture or ocean fertilization. But big-picture, I get more excited by other sequestration methods that put carbon in stable solid form instead of leaving carbon in the form of a high-pressure gas. Nature abhors a pressure differential...
>From the perspective of a portfolio of solid carbon, corals, shellfish and >plankton are fairly stable, at least as long as the ocean's acidity doesn't >get too extreme from carbonic acid from gaseous CO2. But historically that >hasn't scaled as much as soil carbon. The prospects that excites me most are efforts to understand and accentuate natural mechanisms of soil carbon deposition, like the folks who are trying to change grazing practices on managed lands to mimic a boom-bust grass cycle that was historically present with herds of large herbivores. Grasses grow large, spreading their biomass roughly 50/50 above and below ground, herbivores come in and eat everything down to nubs, grass grows back, but abandons some of its deeper roots during the recovery period. Old grass roots decompose slowly due to soil depth, temperature, etc. These methods don't work everywhere, but they work well in some places and some groups are trying to scale them up internationally. There are all kinds of other approaches to soil carbon, including the ever alluring biochar, but restoring natural processes that can deposit stable carbon or restore ecosystems are particularly interesting to me for their co-benefits. This is especially true if they can also be an improvement to status quo agriculture practices that manage most of the world's most productive land but generally lead to a decline in soil carbon and net emissions. Some emerging research is suggesting that organic polyculture farming practices can lead to steady soil carbon decomposition. The devil is always in the details of land management practices and local landscape with these sorts of things, but it is worth researching and identifying best-practices. Before BECCS is deployed at any scale, I would like to see it rigourously compared to natural soil carbon deposition methods, which requires more research and understanding of those mechanisms, costs and tradeoffs. From the perspective of the energy system, the largest value of BECCS comes from its sequestration benefits, not from the electricity, at least according to results from a grid optimization model I helped develop. As far as I can tell, if we want to have a very low chance of anthropogenic catastrophic climate destabilization, we need to cut emissions drastically from all sectors, and deploy carbon scrubbing programs to reduce atmospheric levels. Scrubbing alone will be inefficient to cancel out current emission rates, not to mention cost-prohibitive. Cheers, Josiah Johnston On Jul 27, 2015, at 9:57 PM, Schuiling, R.D. (Olaf) <[email protected]> wrote: > Well, I don't mind somebody claiming that his solution is "by far the most > prominent" of CDR options. The most logical is the one that has worked well > for the past 4.5 billion years, and without which life would not exist on > Earth, namely the weathering of rocks (which is the reaction with rocks, > water and CO2), by which first the CO2 is converted to bicarbonate solutions, > and these are subsequently turned into carbonate rocks thanks to corals, > shellfish and plankton. The risk that the CO2 escapes again from limestones > is rather limited, Olaf Schuiling > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Greg Rau > Sent: dinsdag 28 juli 2015 6:41 > To: geoengineering; [email protected] > Cc: [email protected]; [email protected] > Subject: Re: [geo] Synthesising existing knowledge on the feasibility of BECCS > > Thanks, Andrew. > From the report: "Other approaches for negative emissions have also been > proposed (for example direct capture of CO2 from the air, ocean fertilisation > inter alia) but BECCS is by far the most prominent of these options in > climate change mitigation scenarios and so BECCS will be the focus of this > report." > > GR - How and why did BECCS become "by far the most prominent" option and why > does this automatically mean it's the best and only option, considering how > little R&D has been conducted on any CDR method? At this early stage, are we > really going to place all of our bets on a method that requires doubling > current land CO2 sinks (miraculously without affecting existing land use > services) at a cost of $100/tonne CO2 to make concentrated CO2 that might not > stay permanently stored underground and might cause earthquakes and > groundwater pollution, and, oh by the way, will consume 30-40% of the > bioenergy produced? Or, considering that the Earth's future is at stake, > shall we take the more rational approach and say that CDR is needed, BECCS is > one of a myriad of nascent CDR strategies that demand policies, which, rather > than prematurely christening winners, needs to broadly solicit ideas and > foster objective R&D that allows us to make informed choices about what > CDR portfolio options might make sense? Is this a popularity contest or a > serious investigation as to how to best help save the planet? > > Greg > > -------------------------------------------- > On Sun, 7/26/15, Andrew Lockley <[email protected]> wrote: > > Subject: [geo] Synthesising existing knowledge on the feasibility of BECCS > To: "geoengineering" <[email protected]> > Date: Sunday, July 26, 2015, 11:39 PM > > Download link http://avoid.uk.net/?ddownload=10391 > Web link > http://www.avoid.uk.net/2015/07/synthesising-existing-knowledge-on-the-feasibility-of-beccs/ > > Synthesising existing knowledge on the feasibility of BECCS > (D1.a) > > July 21, 2015 > > Bioenergy with carbon capture and storage (BECCS) (D), Publications, > Reports and policy notes > > > There is a growing and significant dependence on biomass energy with carbon > capture and storage (BECCS) in future emission scenarios that do not exceed > 2°C warming; over a hundred of the 116 scenarios associated with > concentrations between 430–480 ppm CO2 depend on BECCS to deliver global > net negative emissions in the IPCC Fifth Assessment Report (AR5) (Fuss et > al., 2014). Wiltshire et al (2015) found a median value of around 168 GtC > cumulatively removed by 2100 using BECCS in the IPCC scenarios. The > feasibility of this dependence on BECCS is coming under increased scrutiny, > given the interconnected issues of food production, energy provision, > energy system capacity and environmental impacts of large scale bioenergy > coupled with large scale carbon capture and storage (CCS). > > Key Findings > > Biomass energy with Carbon dioxide Capture and Storage > (BECCS) is an > emerging technology that combines large scale biomass energy applications > (including electricity generation) with the capture and storage of CO2 . > BECCS has the potential to remove CO2 from the atmosphere (‘negative > emissions’). > Alternative CO2 removal approaches do not provide the co-benefit of energy > production. > BECCS technology is entering the demonstration phase; the first large scale > (1 MtCO2 yr-1 ) project is due to start operation in > 2015 in > Decatur, Illinois, USA. There are around 15 pilot scale BECCS plants > globally. > Most, but not all, IPCC WG3 emission scenarios that, for a mid-range > equilibrium climate sensitivity, do not exceed 2°C warming require BECCS at > a large scale to reconcile current emission trajectories with cumulative > carbon budgets. > For a given climate target the inclusion of BECCS in emission scenarios > allows higher total carbon emissions, and/or a later peak in emissions, by > removing carbon dioxide from the atmosphere later in the 21st > century.target the inclusion of BECCS in emission scenarios allows higher > total carbon emissions, and/or a later peak in emissions, by removing > carbon dioxide from the atmosphere later in the 21st century. > Many scenarios consistent with 2°C use BECCS to achieve global net negative > emissions (when negative emissions from BECCS are greater than total > emissions from all other sources) by about 2070, with a mean CO2 removal > across IPCC WG3 scenarios of 616 GtCO2 by 2100. > Integrated Assessment Models (IAMs) are based on different assumptions and > constraints; some set a maximum limit of 200 EJ yr-1 for BECCS > applications, whilst others incorporate explicit land use modelling. > IAMs take account of future population, food production and land > availability to varying levels of detail. > The potential global bioenergy resource available for BECCS is a key > uncertainty; composed of uncertainties in land and water availability, crop > yields and residue availability, each associated with socio-economic > assumptions, e.g. future agricultural efficiency gains, population growth, > dietary trends and lifestyles. > Many IAM scenarios assume that BECCS utilises dedicated rain-fed bioenergy > crops grown on surplus agricultural land, assuming medium yields and the > use of crop and waste residues. This seeks to circumvent issues of > competition with food production and other land uses but is strongly > dependent on the underlying socio-economic assumptions. > BECCS may not deliver negative emissions if the biomass energy system is > weakly governed and regulated. A poor choice of biomass type and location > could lead to a net release of carbon to the atmosphere through direct and > indirect land use changes. > Deployment of CCS adds to the costs of energy generation, without strong > climate policy incentives, such as suitable carbon pricing, and regulation > there is no driver to establish the technology. > Almost all scenarios compatible with the 2°C target assume full global > participation in delivering emissions reductions; at scales sufficient to > deliver global net negative emissions, uptake of BECCS in particular will > require new global implementation and governance frameworks in the context > of a highly complex supply chain. > The global potential for negative emissions is estimated to be between > 0 and 10 GtCO2 yr-1 in 2050 and between 0 and 20 GtCO2 yr-1 in 2100. > Assuming 150 EJ yr-1 bioenergy in 2050, 250 EJ yr-1 in 2100, a 90% capture > rate and emissions of 15 kg CO2 GJ-1 from bioenergy production. If BECCS > starts in 2020, the maximum values equate to > 900GtCO2 (245 GtC) removed by 2100. The lower bounds could result from weak > or no climate policy; lack of social acceptability; and/or failure of the > BECCS system to deliver net negative emissions. The confidence in this > estimate is limited as it is based on one expert team using one particular > modelling approach. > > -- > 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/d/optout. > > -- > 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/d/optout. > > -- > 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/d/optout. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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