Term it will not be possible to bring the

Term Paper12/1/2017Submitted by:Urusha Regmi Biochar for Carbon SequestrationTheanthropogenic emissions of Carbon dioxide have risen by more than 3% annuallysince 2012(Raupach et al.

)(Woolf, Amonette, Alayne Street-Perrott, et al.). The earth’s ecosystem is moving towards rapidclimate change which not only dangerous but also irreversible(Solomon et al.). An immediate attention is required to bringabout a timely and ambitious program to mitigate climate change.

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According toseveral studies, to stabilize the mean surface temperature of earth, the cumulativeanthropogenic greenhouse-gas (GHG) emissions must be maintained under a maximumupper limit (Woolf, Amonette, Street-Perrott, et al.). This can be achieved only if the future netanthropogenic emissions approach zero(Solomon et al.)(Broecker)(Matthews and Caldeira)(Allen et al.)(Meinshausen et al.)(Woolf, Amonette, Alayne Street-Perrott, et al.

). Upon exceeding this threshold, it will notbe possible to bring the climate back to safe limits(Woolf, Amonette, Alayne Street-Perrott, et al.). This limit may have, in fact, already beenexceeded(Hansen et al.

). Under these circumstances, strategies thatcan draw down excess atmospheric CO2 concentrations would be of primeimportance(Woolf, Amonette, Alayne Street-Perrott, et al.). Use of biochar in carbon sequestration isone such technique. Biochar is a fine-grainedcharcoal formed from pyrolysis (“Biochar Introduction | US Biochar Initiative”). Biochar use has been recognized as a usefulmethod of improving soil conditions and has been used for over 2500 years now(“Biochar Introduction | US Biochar Initiative”). Biochar’s potential to sequester carbon hasalso been recognized, which stems from its highly recalcitrant nature(Schmidt and Noack)(Kuzyakov et al., “Black Carbon Decomposition andIncorporation into Soil Microbial Biomass Estimated by 14C Labeling”)(Cheng et al.

)(Woolf, Amonette, Alayne Street-Perrott, et al.). This paper aims to discuss the possible useof biochar as a carbon capture technique through a few literature reviews of publishedscientific studies.

 History and Background: Biochar isfound naturally in some places because of vegetation fires(“Biochar Then & Now | US Biochar Initiative”). However, due to its benefits on soilproperties, it is also intentionally produced by burning biomass. Biochar hasbeen used in agricultural practices in the Amazon Basin of South America for aslong as 2500 years(“Biochar Then & Now | US Biochar Initiative”). The traditional method of biocharproduction is to pile the biomass in an earthen pit and cover it to burn itunder low oxygen conditions(“Biochar Then & Now | US Biochar Initiative”). This method emits half the carbon dioxide presentin the original biomass in the atmosphere. The heat energy produced also goesto waste. This method is still practiced in developing countries(“How Is Biochar Made?”).  However,the method of producing biochar by pyrolysis in specially designed furnaces isvery environmentally friendly.

It can capture all the emissions from burning. Theseemissions which include volatile gases and hydrocarbons are also known assynthetic gas(syngas). Syngas can be used as natural gas. The liquid captured,known as biooils can also be used as a source of energy. In addition, the heatenergy released can also be captured and used to electricity generation. Thecarbon-rich biochar that is left behind can then be applied to soil(“How Is Biochar Made?”).  The worldproduction of biochar in 2005 was more than 44 million tons (“Countries Compared by Energy > Charcoal> Production from Charcoal Plants. International Statistics atNationMaster.

com”)(“Methods for Producing Biochar and Advanced Biofuelsin Washington State Part 1: Li Eactors Terature Review of Pyrolysis R”). The feedstock used for biochar are wasteproducts like excess manure, wood debris, waste from food processing etc(“How Is Biochar Made?”). While biochar has the potential to resolvemany environmental, social and technological issues(“Methods for Producing Biochar and Advanced Biofuelsin Washington State Part 1: Li Eactors Terature Review of Pyrolysis R”), the focus of this paper will be to discuss itsapplication in carbon sequestration.

 Soil contains3.3 times more carbon than the atmosphere and 4.5 times more than plants andanimals making it an important source of carbon dioxide and other greenhousegases. However, with the right management, it can also be a potential sink(“Methods for Producing Biochar and Advanced Biofuelsin Washington State Part 1: Li Eactors Terature Review of Pyrolysis R”).

Pyrolysis of biomass transforms the carbonin the biomass into stable carbon structures in biochar which is recalcitrantagainst decomposition. The biochar can remain sequestered in the soil from a hundredto thousands of years. Thus, biochar application can make soil a carbon sinkwhile also improving soil quality and productivity(“Climate Change and Biochar | International BiocharInitiative”)(“Biochar Carbon Sequestration – Introduction”).  In 2010, DonHofstrand, Professor Emeritus at Iowa Stata University discussed BiocharSystems for carbon sequestration in an Agricultural Marketing ResourceCenter(AgMRC) Renewable Energy Newsletter. Hofstrand began by saying thatbiochar is carbon negative. He further discusses the underlying assumptions ofthe analysis of the potential size of biochar systems industry. This analysiswas conducted by the International Biochar Initiative(“Using Biochar Systems to Sequester Carbon | AgriculturalMarketing Resource Center”). As biochar is derived from biomass, itsavailability becomes critical to the size of biochar system industry.

Theanalysis used just crops and forest residues as biomass sources which is a verysmall percentage of the world’s Net Primary Production (NPP). Examples havebeen given for three different scenarios: conservative, moderate andoptimistic. Under the conservative scenario, the use of 27% of the existingcrops and forests biomass residues in a biochar system will comprise only 1.2%of the world’s NPP.

Similarly, use of 50% for moderate approach and 80% foroptimistic approach will comprise of 2.1% and 3.2% of the NPP(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”). Thus, adequate biomass availability hasbeen assumed. Next assumption is that adequate land area is available forstoring biochar for sequestration. Biochar is added to the land from which thebiomass was taken(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”). Thus, any loss in soil organic matter bythe removal of crop residues for biochar production is restored by returningbiochar to the land which in fact will improve the productivity(Woolf, Amonette, Alayne Street-Perrott, et al.

)(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”). The pyrolysis system used is assumed to bea slow-pyrolysis (fast pyrolysis produces more biooil and less biochar thanslow pyrolysis(Woolf, Amonette, Alayne Street-Perrott, et al.)) modern high-yielding technology with a 40%carbonization rate(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”). The system is also assumed to producerenewable energy, which can replace fossil fuel energy, thus reducing carbonemissions. Biochar is assumed to be stable and remain sequestered in the soilsfor more than a hundred years. The estimates of the carbon sequestered forconservative, moderate and optimistic scenarios were presented in a graph asfollows. Wedge represents one gigaton of carbon sequestered per year. From thegraph we can see that the biochar takes a few years to reach its fullpotential, after which, it sequesters carbon in a stable range of 0.

2 to 0.8 billiontons(gigaton) of carbon per year. The Optimistic Plus scenario in the graphincludes the reduction in emission of nitrous oxide gas along with carbondioxide. The nitrous oxide emissions are assumed to be reduced by half(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”). Fig1: Carbon Sequestrationor Offset in different scenarios over time. Reprinted from: “Using Biochar Systemsto Sequester Carbon | Agricultural Marketing Resource Center.

” N.p., n.d. Web.2 Dec. 2017. Bioenergyemits carbon that is originally present as atmospheric carbon and thus iscarbon neutral whereas fossil fuels emit carbon that is originally sequesteredin the soil and is carbon positive.

Thus, carbon offset is generated throughthe substitution of fossil energy by the carbon neutral bioenergy generated inthe process of biochar production. In addition, the carbon dioxide generatedduring biochar production can be captured and sequestered. The InternationalBiochar Initiative took into the account the collective effect of carbonsequestration through biochar, substitution of fossil energy with bioenergy andcapture and sequestration of excess carbon during biochar production. The neteffect is presented in the following graph(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”).

 Fig 2:Combined Carbon Sequestration or Offset in different scenarios over time.Reprinted from: “UsingBiochar Systems to Sequester Carbon | Agricultural Marketing Resource Center.”N.p., n.

d. Web. 2 Dec. 2017.  Theconservative scenario results in net reduction of more than 0.5 gigatons ofcarbon per year.

The net reduction in moderate and optimistic scenarios arearound 1.25 gigatons and almost 2 gigatons of carbon per year respectively.Under the optimistic plus scenario, the reduction is about 2.2 gigatons peryear by 2050(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”). The author further discusses the role thatbiochar systems can play in reducing greenhouse emissions levels. The followingtable has been presented in the article to show the contribution of biocharsystems in GHG emission offset. Biochar alone can reduce the emissions by 10%in average.

When the collective effect of all three offsets is considered, thebiochar system can contribute from 20% to 30% of the reduction(“Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center”).  Table 1PotentialGHG emission offsets by 2050 under various scenarios of biochar systemsSource: “Using Biochar Systems to Sequester Carbon |Agricultural Marketing Resource Center.” N.p., n.d. Web.

2 Dec. 2017. Another studytitled “Sustainable biochar to mitigate global climate change”(Woolf, Amonette, Alayne Street-Perrott, et al.) in 2010 studied the maximum potential ofbiochar to mitigate climate change with a sustainable approach(Woolf, Amonette, Alayne Street-Perrott, et al.). This theoretical upper limit of the climatechange potential of biochar under current conditions is termed as maximumsustainable technical potential (MSTP). The author describes MSTP as “what canbe achieved when the portion of the global biomass resource that can beharvested sustainably (that is, without endangering food security, habitat orsoil conservation) is converted to biochar by modern high-yield, low-emission,pyrolysis methods”(Woolf, Amonette, Alayne Street-Perrott, et al.).

The paper doesn’t take into account anysocio-economic and cultural barriers. However, it assumes a maximum rate ofcapital investment which is in consistence with that estimated to be requiredfor mitigation of climate-change. The paper describes the sustainable biocharconcept with the aid of the following diagram. The paper discusses thedependence of the climate-change mitigation potential of biochar and bioenergyon the fertility of the soil being amended, the carbon intensity of the fuelbeing offset, and the feedstock used for deriving them (type of biomass). Locationswith high soil fertility and where coal is the fuel being offset is moresuitable for bioenergy production. For all other situations, biochar has ahigher climate-change mitigation potential than bioenergy (Woolf, Amonette, Alayne Street-Perrott, et al.

).  Fig 3:  Sustainable Biochar Concept Overview. Reprintedfrom: Woolf,Dominic et al. “Sustainable Biochar to Mitigate Global Climate Change.” (2010):n.

pag. Web. 3 Dec. 2017 Sustainable biomass-feedstockavailability is crucial to any biochar system. Thus, the study uses a strictset of criteria to assess the availability of feedstock for biochar to ensurethe approach is sustainable. Land conversion to generate biomass is of primaryimportance as it can have adverse effects on the ecosystem.

In addition, it canlead to release of carbon stored in the soils and biomass(Woolf, Amonette, Alayne Street-Perrott, et al.). This results in unacceptable limits of carbonpay-back times before any net reduction of atmospheric carbon dioxide isachieved. (Fargione et al.

)(Woolf, Amonette, Alayne Street-Perrott, et al.). For example, clearance of rainforest forland conversion to produce biomass-crop can results in carbon payback times morethan 50 years. Similarly, the conversion of peatland rainforest for productionof biomass-crop can result in carbon-payback times in the order of 325 years(Woolf, Amonette, Alayne Street-Perrott, et al.). Therefore, in this study, it has beenassumed that no land clearance was used to provide feedstock.

Due to adverseconsequences on food security, it is also assumed that no food production landwas converted for biomass production. The analysis is restricted to systemswhich use modern, high-yield, low emission pyrolysis technology. Inconsideration with these constraints the paper presents a biomass-availabilityscenario for their estimate of MSTP. They also present two additionalscenarios, Alpha and Beta (represent lower demands). In the Alpha scenario, thebiomass availability is restricted to moderate amount of agroforestry andbiomass cropping together with residues and waste available with the use ofcurrent practices. All scenarios are ambitious(Woolf, Amonette, Alayne Street-Perrott, et al.

).Table 1AnnualSustainable Biomass feedstock available globally Source: Woolf, Dominic et al.”Sustainable Biochar to Mitigate Global Climate Change.

” (2010): n. pag. Web. 3Dec. 2017  Fig 4:  Net GHG Emissions avoided.

Reprinted from: Woolf,Dominic et al. “Sustainable Biochar to Mitigate Global Climate Change.” (2010):n. pag.

Web. 3 Dec. 2017 The analysisin this paper states that a maximum of 12% of current anthropogenic CO2-Cequivalent emissions, which is 1.

8Pg CO2-Ce (per year) of the 15.4Pg CO2-Ceemitted annually, can be potentially offset by the sustainable globalimplementation of biochar(Woolf, Amonette, Alayne Street-Perrott, et al.). The writer further says that the total netoffset from biochar implementation over a time of a century would 130Pg CO2-Ce(Woolf, Amonette, Alayne Street-Perrott, et al.). Half the amount of avoided emissions occursdue to net carbon sequestration by biochar however the remaining 30% and 20%are due to replacement of fossil fuel by bioenergy and avoided methane andnitrous oxide emissions respectively. The paper also states that a maximumoffset of 10% of anthropogenic CO2-Ce emissions can be achieved on maximizingbioenergy production rather than biochar from sustainably obtained biomass. Adetailed breakdown, shows that carbon stored as biochar is the soil (43-49 PgCO2-Ce) and fossil fuel offsets (18-39 Pg CO2-Ce) are the highest contributorsto reduced emissions.

Among the negative feedbacks, largest was found to bebiochar decomposition (8-17 Pg CO2-Ce). The uncertainty of the models wasestimated with Sensitivity and Monte Carlo analyses. The sensitivity isstrongest to the half-life of the recalcitrant fraction of biochar. The netavoided GHG emissions can vary by -22% to +4% from the value obtained with 300years as the baseline assumption. However, most of this variation occurs forhalf-life<100 years.

For half-life>100 years, which is a more realisticscenario, sensitivity is low as biochar production can be more rapid thanbiochar decay(Woolf, Amonette, Alayne Street-Perrott, et al.). Current data available in literature showthat the half-life of recalcitrant fraction of biochar in soil is in themillennial range (Sombroek, Nachtergaele, and Hebel)(Kuzyakov et al., “Black Carbon Decomposition andIncorporation into Soil Microbial Biomass Estimated by 14C Labeling”)(Kuzyakov et al.

, “Black Carbon Decomposition andIncorporation into Soil Microbial Biomass Estimated by 14C Labeling”)(Cheng et al.) (Woolf, Amonette, Alayne Street-Perrott, et al.).  Fig 5:  Detailed breakdown showing cumulative avoidedGHG.

Reprinted from: Woolf,Dominic et al. “Sustainable Biochar to Mitigate Global Climate Change.” (2010):n. pag. Web.

3 Dec. 2017 An articletitled “Biochar as a viable carbon sequestration option: Global and Canadian perspective”discusses the availability of sources for biochar application the amount ofcarbon that can be sequestered.  Industrialscale techniques of carbon capture from air by the closed-cycle sodiumhydroxide absorption is being contemplated at a cost of $500/tC and at half thecost when combined with carbon capture by biomass(Keith, Ha-Duong, and Stolaroff). Significant cost is associated with thecompression and pumping of carbon dioxide into ground. These costs are howevernot incurred in biochar production and application for soil amendment.

Thepaper doesn’t study the interactions of biochar with soil. Of the totalanthropogenic emissions of carbon from fossil fuel and cement production), 4.1GtC/yr remains in the atmosphere. The paper assumes that the biomass availablefor conversion to biochar is 10% of the net primary production (NPP) whose estimationhas been taken as 60.6 GtC/yr, which was the estimated value at the time the studywas done(Amonette, Lehmann, and Joseph). The resultant biochar production assumingconversion of 50% of biomass carbon to biochar was 3 GtC/yr. The carbon offset achievedthrough combustible products (60% of the 50% biomass) was 1.8 GtC/year.

Theremaining 40% (1.3 GtC/yr) is used for pyrolysis). This shows that 10% of NPPbiomass would be enough to offset the annual increase in carbon dioxide in theatmosphere. Further the paper discusses the distribution of the biocharproduced. Assuming the addition of 3% biochar (percentage by mass) into the top30cm of the total agricultural area which is around 45 mil. Km2 (Ghazi et al.) worldwide,the total capacity worldwide would be 600 GtC of biochar.

The author says thatat the rate of 3 GtC/yr, this potential reservoir for biochar would be availablefor two centuries. From Canadian perspective, the author says that Canada hasthe largest reserves for biomass to produce biochar. From the collectivecontribution of biomass from forest harvesting, forest fire reduction, mountainpine beetle infestation, agricultural residues and fast rotation silviculture,amounts of biomass 5 times larger than the annual requirements would beachieved. While this could fully offset total carbon emissions, the landavailable for storing biochar is limited(Matovic). It is crucialto understand that the ReferencesAllen, Myles R. et al. “WarmingCaused by Cumulative Carbon Emissions towards the Trillionth Tonne.” Nature458.

7242 (2009): 1163–1166. Web. 3 Dec. 2017.Amonette, J.

, J.Lehmann, and S. Joseph.

“Terrestrial Carbon Sequestration with Biochar: APreliminary Assessment of Its Global Potential.” American Geophysical Union,Fall Meeting 2007, abstract #U42A-06 (2007): n. pag.

Web. 4 Dec. 2017.

“Biochar CarbonSequestration – Introduction.” N.p., n.d. Web.

3 Dec. 2017.”Biochar Introduction |US Biochar Initiative.” N.p., n.d. Web.

30 Nov. 2017.”Biochar Then &Now | US Biochar Initiative.” N.p., n.d. Web.

3 Dec. 2017.Broecker, Wallace S. “CLIMATECHANGE: CO2 Arithmetic.” 315 (2007): n. pag. Web. 3 Dec.

2017.Cheng, Chih-Hsin et al. “Stabilityof Black Carbon in Soils across a Climatic Gradient.” Journal of GeophysicalResearch: Biogeosciences 113.G2 (2008): n/a-n/a. Web. 4 Dec.

2017.”Climate Change andBiochar | International Biochar Initiative.” N.p., n.d.

Web. 3 Dec. 2017.”Countries Compared byEnergy > Charcoal > Production from Charcoal Plants.International Statistics at NationMaster.

com.” N.p., n.d. Web. 3 Dec.

2017.Fargione, Joseph et al. “LandClearing and the Biofuel Carbon Debt.” Science (New York, N.Y.) 319.5867(2008): 1235–8.

Web. 4 Dec. 2017.Ghazi, Polly et al. “UnitedNations Environment Programme.” n. pag. Web.

4 Dec. 2017.Hansen, James et al. “TargetAtmospheric CO 2?: Where Should Humanity Aim?” n.

pag. Web. 3 Dec. 2017.

“How Is Biochar Made?”n. pag. Print.Keith, David W., MinhHa-Duong, and Joshuah K.

Stolaroff. “Climate Strategy with Co2 Capture from theAir.” Climatic Change 74.1–3 (2006): 17–45. Web. 4 Dec. 2017.Kuzyakov, Yakov et al.

“BlackCarbon Decomposition and Incorporation into Soil Microbial Biomass Estimated by14C Labeling.” Soil Biology and Biochemistry 41.2 (2009): 210–219.

Web.4 Dec. 2017.—.

“Black CarbonDecomposition and Incorporation into Soil Microbial Biomass Estimated by 14CLabeling.” Soil Biology and Biochemistry 41.2 (2009): 210–219. Web. 4Dec. 2017.Matovic, Darko.

“Biocharas a Viable Carbon Sequestration Option: Global and Canadian Perspective.” Energy36.4 (2011): 2011–2016.

Web. 4 Dec. 2017.Matthews, H. Damon, andKen Caldeira.

“Stabilizing Climate Requires near-Zero Emissions.” GeophysicalResearch Letters 35.4 (2008): 1–5.

Web.Meinshausen, Malte etal. “Greenhouse-Gas Emission Targets for Limiting Global Warming to 2?°C.” Nature458.7242 (2009): 1158–1162. Web. 3 Dec.

2017.”Methods for ProducingBiochar and Advanced Biofuels in Washington State Part 1: Li Eactors TeratureReview of Pyrolysis R.” (2011): n. pag. Web. 3 Dec. 2017.Raupach, Michael R etal.

“Global and Regional Drivers of Accelerating CO2 Emissions.” Proceedingsof the National Academy of Sciences of the United States of America 104.24(2007): 10288–93. Web. 3 Dec. 2017.Schmidt, Michael W.

I.,and Angela G. Noack.

“Black Carbon in Soils and Sediments: Analysis,Distribution, Implications, and Current Challenges.” Global BiogeochemicalCycles 14.3 (2000): 777–793. Web. 4 Dec. 2017.Solomon, Susan et al. “IrreversibleClimate Change due to Carbon Dioxide Emissions.

” Proceedings of the NationalAcademy of Sciences of the United States of America 106.6 (2009): 1704–9.Web. 3 Dec. 2017.Sombroek, Wim G, Freddy0 Nachtergaele, and Axel Hebel.

“Amounts, Dynamics and Sequesterin of Carbon inTropical and Subtropical.” Royal Swedish Academy of Sciences Amounts AmbioThe Royal Colloquium 22.7 (1993): 417–426.

Web. 4 Dec. 2017.

“Using Biochar Systemsto Sequester Carbon | Agricultural Marketing Resource Center.” N.p., n.d.

Web.2 Dec. 2017.

—. N.p., n.

d. Web. 3Dec. 2017.Woolf, Dominic, James EAmonette, F Alayne Street-Perrott, et al. “Sustainable Biochar to MitigateGlobal Climate Change.” (2010): n.

pag. Web. 3 Dec. 2017.

Woolf, Dominic, James EAmonette, F Alayne Street-Perrott, et al. “Sustainable Biochar to MitigateGlobal Climate Change.” Nature communications 1 (2010): 56. Web. 4 Dec.2017.