Johannes LehmannDepartment of Crop and Soil SciencesCornell University

Biochar and Mitigation of Climate Change

Biochar System – Core Principle

Lehmann, 2007, Frontiers in Ecology and the Environment 7, 381-387

Biochar and Climate Change Mitigation

Lehmann, 2007, Nature 447, 143-144

Natural Occurrence

Biochar Abundance in World Soils

Krull et al, 2008, in: Nova Sci Publ

(World Soils Archive of ISRIC)

Biochar Abundance in Soils

NSA Lead ProfilesQLD TransectDWN TransectMajor Australian CitiesKatherineDaly Waters

0

5

10

15

20

25

30

35

10203040506070 80 90100 NSA (N=58)QLD (N=114)

DWN (N=280)

N

umbe

r of s

oils

(% o

f all

test

ed s

oils

)

Black Carbon (% of total organic C)

Average≈20%(n=452)

34Gt SOC (0-1m)(Grace et al., 2006, Carbon Balance and Management 1,14)

20% ≈ 7Gt0.1Gt CE /yr fossil fuel(Department of Climate Care, 2008)

Lehmann et al, 2008, Nature Geoscience 1, 832 - 835

Biochar Stability and Storage Time

About 1.5 to 2 orders of magnitude greater than uncharred biomass

Mean residence time in soil: ~1000 years (at 10°C)Baldock and Smernik, 2002, Organic Geochemistry 33, 1093-1109Bruun et al., 2008, Organic Geochemistry 39, 839-845Cheng et al., 2008, Journal of Geophysical Research, 113, G02027Lehmann et al, 2008, Nature Geoscience 1, 832 - 835 Liang et al, 2008, Geochimica et Cosmochimica Acta 72, 6096-6078Kuzyakov et al., 2009, Soil Biology and Biochemistry 41, 210-219 Major et al., 2009, Global Change Biology, doi: 10.1111/j.1365-2486.2009.02044.x

Biochar Stability - Measurements

Nguyen, Lehmann et al., 2008, Biogeochemistry 89: 295-308

(BC from forest clearing,false-time series on UltisolsWestern Kenya)

Large proportion of physical export likely

0 20 40 60 80 100

BC

con

tent

s (m

g C

g-1

soil)

0

2

4

6

8

10

12

14

16A

BC=3.51+9.16e-0.12years

R2=0.80, P=0.02

Age (years since BC deposition)

MRT of 8 years

(BC quantified by NMR and molecular mixing model)

Biochar Stability - Measurements

Hammes et al., 2008, Biogeosciences Discussions 5: 661-683

at 1900

Biochar-type carbon (probably low estimate)Russian Steppe Soil

at 1997

Biochar Fate in Soils

20-53% eroded!(Challenge for Carbon Trading)

Cumulative flux over 2 years Proportion of applied BC (%)

Respired as CO2 4.0

Leached as large particles POC (below 0.3m) 0.5Leached as small particles DOC (below 0.3m) 2.0

Major et al., 2009, Global Change Biology, doi: 10.1111/j.1365-2486.2009.02044.x

Colombian Llanos

Biochar Stability - Measurements

Surface oxidation?

Brodowski, 2005, PhD thesis

(pooled data from corn and rye BC (350°C), 20°C, at 70% water holding capacity, 3 replicates)

Measured using the BPCA biomarker method

Important Nuances? Quality of Biochar

Corn-BC Oak-BC0

5

10

15

20350°C600°Ca

bb b

(1 year, 30°C, in sand culture, N=8)

Car

bon

loss

rate

(% y

ear-1

)

Nguyen and Lehmann, 2009, Organic Geochemistry 40, 846-853

A (corn-350-BC) B (corn-600-BC)

5 nm 5 nm

Biochar Stability and StabilizationChemical stability + particulate nature + mineral?

(a) (b)

(c) (d)

Lehmann et al, 2008, Nature Geoscience 1, 238-242Lehmann et al, 2009, in: Earthscan Publ

10 μm

Total Carbon Black Carbon

Stabilization by Interactions with Minerals?

2 μm

aromatic carbon aliphatic carbon

carboxylic carbon phenolic carbon

total carbon nitrogen calcium

iron aluminum

Unpubl. data

Effects of Biochar on Total GHG

BiocharCO2 N2O, CH4

?

Effects of Biochar on Total GHG

Wardle et al., 2008, Science 320: 629

Disappearance(≠decomposition!)Lehmann and Sohi, 2008, Science 321, 1295

Effects of Biochar on Total GHG

Spokas et al., 2009, Chemosphere 77: 574-581

HapludollBiochar from fast pyrolysis

Biochar added to 5g soil (g)

Time (days)

0 100 200 300 400 500Cum

ulat

ive

C m

iner

aliz

atio

n [m

g C

O2-

C g

-1 so

il]

0

2

4

6

8

10

12

LSD0.05

A LSD0.05

+OM

-OM

Anthrosol HAT

Adjacent HAT

Anthrosol ACU

Adjacent ACU

Anthrosol DS

Adjacent DS

+AOM

–AOM

Effects of Biochar on Total GHG

Liang et al., 2009, Organic Geochemistry published online

Lower C mineralization in BC-rich Anthrosols

AOM=sugar cane(isotope tracing)Incubation at 30°CN=4

(Terra PretaCentral AmazonBiochar ages range from 800 to 7,000 years)

Effects of Biochar on Total GHG

Liang et al., 2009, Organic Geochemistry published online

NS

Mineralization of added OM

BC-rich soils

P contents

+43-125%P<0.05

Microbial Biomass

+173-3200% +19-340%

Added OMin fraction >1.8g/cm3

AOM=sugar cane(isotope tracing)Incubation at 30°CN=4

Effects of Biochar on N2O Emissions

Bhupanderpal-Singh et al., 2009, JEQ in press

VertisolAlfisol

poultry manure 400°C

poultry manure 550°C

wood 550°C

wood 400°C

control

Up to 73% reduction

Partly no reduction control

Life-Cycle Emission Reductions

Roberts et al., in revision

Energy Balance

6.99.1Corn stover (crop residue)

6.99.0Wheat straw

5.37.0Switchgrass

2.33.0Forage corn

Biochar to soil

Biochar to energy

Energy balance (MJ/MJ), Slow pyrolysis

Pyrolysis40-55%carbon

75-90%carbon

75% mass loss

50% carbon loss

BIOMASS BIOCHAR

Gaunt and Lehmann, 2008, Environmental Science and Technology 42: 4152-4158

Emission Balance

Gaunt and Lehmann, 2008, Environmental Science and Technology 42: 4152-4158

12,551-18,5954083-7710Bioenergy crops

9575-11,8332002-3736Crop residues

Biochar to soilBiochar to energy

Avoided Emissions (kg CO2/ha/yr), Slow pyrolysis

Fuel Efficiency – Cook StovesLower indoor pollution=lower respiratory

+ eye infectionsCase Study Kenya

Traditional Stove Improved Stove Biochar Stove

Mas

s (g

/kg

food

coo

ked)

-400

-200

0

200

400

600

800

1000

1200

1400

1600Wood Use Crop Residues Charcoal Residue Biochar

baa

Fuel Efficiency – Cook StovesCase Study Kenya

Torres, unpubl. data (n=20 for biochar stove (first generation, to be improved);average of one day cooking)

Reduction in wood use: 51% (±SE3.4; n=20)(Torres, unpubl. data)

Can the same amount of energy be generated with half of the carbon emitted?

Life-Cycle Assessment: Emission Reductions

Whitman et al., unpublished

Kenya-based scenario of cook stoves

Model Sensitivity 350% 75% 95% 100%Total CO2e in soil compared to baseline per T biomass

2

1.5

1

0.5

00 25 50 75 100

Time (year)

Tota

l soi

l C st

ocks

as c

ompa

red

to 3

-sto

ne

syst

em, p

er u

nit f

uel (

tCO

2e/t

dry

biom

ass)

Model Sensitivity 350% 75% 95% 100%Total CO2e in soil compared to baseline per T biomass

2

1.5

1

0.5

00 25 50 75 100

Time (year)

Tota

l soi

l C st

ocks

as c

ompa

red

to 3

-sto

ne

syst

em, p

er u

nit f

uel (

tCO

2e/t

dry

biom

ass)

Emissions from gasifier stove(MacCarty et al 2008)

MRT of BC 100-1000yrsFraction of passive BC: 0.6-0.9Fraction of crop residue used: 0-100%Fraction converted to BC: 0.25-0.5Systems dynamics modeling (Vensim)

Best preliminary estimate:Emission reduction: 8 t CO2e/yrRevenue ($5/t CO2e): $40/yr/household

Fuel Efficiency

Torres, unpubl data

Case Study Western Kenya (Kakamega)

Fuel reduction:• Fuel security• Lower fuel acquisition time• Lower pressure on natural resources

Distance per headload: 2.1 km (0.1-6.3)Wood saved: 4.9 t/household/year (0.9-19.2)Time saved: 6.2 hours/household/week (0.5-32)(30 households)

Time (years)

0 20 40 60 80 100

Annu

al C

rop

Yiel

ds (t

dry

gra

in/h

a) -

long

plu

s sh

ort r

ains

3

4

5

6

7

8

9

10

3-Stone Stove Pyrolysis Stove

Traditional Stove

Biochar Stove

Crop Yield

Life-Cycle Assessment: Soil and Crop

Whitman et al., unpublished

Systems dynamics modeling (Vensim)

Case Study Western Kenya (Kakamega)

Biochar Accounting FrameworkParaguay

• Relatively easy counting• Proof of source possible (MIR, TG-IMS)• Low risk of rapid evasion• Result of multiple emission reductions

Biochar Quantification in Soils

Hammes et al, 2007, Global Biogeochem Cycles

Biochar Quantification in Soils

Janik et al, 2007, AJSS

Mid-Infrared versus UV-NMR

Rapid methodInexpensiveLimited sample prep

Biochar Quantification in Soils

Unpubl. data (Lopez-Capel, Manning, Lehmann)

Wood biochar

δ13C -21‰

δ13C -24‰

Emissions Accounting

Biochar CO2 N2O, CH4

N2O, CH4N2O, CO2

Time since conversion (years)

0 20 40 60 80 100 120

Mai

ze g

rain

yie

ld (t

ha-1

)

2

4

6

8

10

12BiocharSawdust Manure Tithonia

LSD0.05

Growth Enhancement Dependent on Soil Properties

Kimetu et al., 2008, Ecosystems 11: 726-739

Biochar applied each seasonKenya (n=3)

The Way Forward

Platforms/Typology of biochar Systems:

- systems emission balance can be calculated- biochar quality can be controlled- soil effects can be estimated

WasteManagement

EnergyProduction

SoilImprovement

Mitigation ofClimate Change

Social, Financial Benefits

Biochar Benefits – Systems Dimension

WasteManagement

EnergyProduction

SoilImprovement

Mitigation ofClimate Change

Social, Financial Benefits

Biochar Benefits – Systems Dimension

WasteManagement

EnergyProduction

SoilImprovement

Mitigation ofClimate Change

Social, Financial Benefits

Biochar Benefits – Systems Dimension

WasteManagement

EnergyProduction

SoilImprovement

Mitigation ofClimate Change

Social, Financial Benefits

Biochar Benefits – Systems Dimension

Biochar – The Way Forward

Not “WHETHER”, but “WHERE”

Variation but also Uncertainties

Nitrogen balance

Biochar handling

Quantification of site-specific effects

Thanks

National Science Foundation – Ecosystem Sciences, Geobiology and Biocomplexity Programs, NSF-IGERT, USDA-NRI, USAID

Rothamsted Research, INPA and Cornell University for financial support.Sue Wirick, Chris Jacobsen, Mirna Lerotic (SUNY Stony Brook), Chithra

Karunakaran (CLS) for their help with sample analysis.Eduardo Neves, Fernando Costa (Universidade de Sao Paulo), James Petersen

(University of Vermont), Manuel Arroyo-Kalin (University of Birmingham) for the samples.

Lindsey Keller (Johnson Space Center), Jim Heyne for discussion about embedding.

Akio Enders (Cornell University) for sample preparation.Yuanming Zhang (Cornell University) for invaluable help with sectioning.Saran Sohi, Dawit Solomon, Biqing Liang, Julie Major, James Kinyangi, Chih-Hsin

Cheng, Janice Thies, Jan Skjemstad, Evelyn Krull, Kelly Hanley, Kelli Roberts, Thea Whitman, Dori Torres and many others