Dairy production and the carbon cycle

the importance of carbon sequestration

Corina van Middelaara

Christel Cederbergb, Pierre Gerberac, Martin Perssonb, Imke de Boera

a Animal Production Systems, Wageningen University, the Netherlands b Physical Resource Theory, Chalmers University of Technology, Sweden c UN Food and Agricultural Organisation, Italy; The World Bank, USA

Reducing global warming?

Livestock production responsible for 15% of

GHGs

Demand for animal source

food to double by

2050

“Prevent dangerous

anthropogenic interference with climate

system”

Approaching temperature limit of 2 °C

Measures with a short or long term mitigation potential

Carbon storage in agricultural soils offers potential

Content

Dairy production and the carbon cycle

Climate impact of greenhouse gases

Case study: grass based vs maize based system

Results: the importance of C sequestration

Conclusions

Dairy production and the carbon cycle

CO2

CH4

Organic C Organic C

Fossil C Fossil C

Millions of years Centuries to Decades Now

CO2 CO2

Organic C

CH4

•

Importance of soil carbon sequestration?

One of most promising

mitigation options for agriculture

(Petersen et al., 2013)

Off-set 5-15% of global fossil fuel

emissions (Goglio et al. 2015)

Absorb the equivalent of the

annual anthrophogenic CO2 emissions

(The 4 ‰ Initiative) Long term global warming impacts hidden by short term solutions?

(Jørgensen and Hauschild, 2013)

0

50

100

150

200

250

0 25 50 75 100

Year

0.0

0.5

1.0

1.5

2.0

0 25 50 75 100

Year

Persson et al. 2015 (based on AR5, IPCC 2013)

Rad.

forc

. (m

W/m

2)

Rad.

forc

. (m

W/m

2)

Climate impact of CO2 and CH4

Radiative forcing of one million tonnes of CO2 Radiative forcing of one million tonnes of CH4

0

50

100

150

200

250

0 25 50 75 100

Year

0.0

0.5

1.0

1.5

2.0

0 25 50 75 100

Year

Persson et al. 2015 (based on AR5, IPCC 2013)

Rad.

forc

. (m

W/m

2)

Rad.

forc

. (m

W/m

2)

Climate impact of CO2 and CH4

Radiative forcing of one million tonnes of CO2 Radiative forcing of one million tonnes of CH4

DT

DT

Biogenic versus fossil CH4

Atmospheric CH4 is broken

down to CO2

Short term C cycle excluded

CO2 from biogenic CH4

excluded (∙∙∙∙∙)

Long term C cycle included

CO2 from fossil CH4

included (∙∙∙∙∙)

CO2

CH4

Organic C

Fossil C

CH4

•

Case study

Aim

Determine the importance of carbon

sequestration regarding the GWP of dairy

production at various time scales

Method

Farm A [13] Farm B [27]

Land area [ha] 35 70

Grassland [%] 99 54

Maize land [%] 1 32

Dairy cows [#] 57 124

FPCM [kg cow-1 yr-1] 8,047 9,082

FPCM [kg ha-1 yr-1] 13,449 18,361

FADN, 2011;2012;2013

grass based [Farm A] vs maize based [Farm B]

How does C seq. affect the GWP of the farms over time?

How does C seq. affect the comparison between farms?

Cradle-to-farm gate analysis

Feed & food

Fertilizers pesticides, fuels

Processing Retail Consumption

Milk Manure

Dairy husbandry

Grass Maize

Roughage

Fattening

Cows

CO2 ; CH4 ; N2O

Carbon sequestration in grasslands

Introductory Carbon Balance Model (ICBM) (Kätterer and Andrén, 1999)

Simulates soil C dynamics based on soil characteristics, nitrogen input, climatic conditions, and management operations

Calibrated and tested for the Dutch situation by Vellinga et al. (2004)

Most optimal scenario C seq.

grassland what is the

maximal potential?

No increase in soil C maize

land

No C losses grass- and

maize land

Results – pulse of emission (per ton fat-and-protein-corrected milk)

GWP (100 yrs) / t FPCM

Farm A (grass)

1139 kg CO2eq

Farm B (maize)

1078 kg CO2eq

GWP (100 yrs) / t FPCM

Farm A (grass) (kg CO2eq)

Excl C seq 1139 100%

Incl C seq (t100) 1020 90%

Incl C seq (t20) 1120 98%

Farm B (maize)

Excl C seq 1078

Incl C seq (t100) 1024

Incl C seq (t20) 1069

Results – pulse of emission (per ton fat-and-protein-corrected milk)

-

100

Results – continuous emission (per ton fat-and-protein-corrected milk yr-1)

GWP (100 yrs) / t FPCM

Farm A (grass)

10% lower with C-seq compared to

without C seq

12.2 billion litres of milk (NL, 2013)

1.4 billion tonnes of CO2 per year;

DT 0.004 ˚C lower with C-seq

compared to without C-seq

RF per ton FPCM of Farm A (grass) relative to that of Farm B (maize)

Results – continuous emission (per ton fat-and-protein-corrected milk yr-1)

Excl C seq.

Incl C seq.

100

Conclusions

Mitigation potentail of carbon sequestration highly dependent on grassland age and storage time Carbon sequestration can lower the impact of a system for a certain time period buying time

At the long term, measures to reduce annual emissions might be more efficient than carbon sequestration for reducing global warming

Thank you for your attention

Corina.vanMiddelaar@wur.nl