Dairy production and the carbon cycle

Transcription

1 Dairy production and the carbon cycle the importance of carbon sequestration Corina van Middelaar a Christel Cederberg b, Pierre Gerber ac, Martin Persson b, Imke de Boer a 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

2 Reducing global warming? Livestock production responsible for 15% of GHGs Prevent dangerous anthropogenic interference with climate system Measures with a short or long term mitigation potential Demand for animal source food to double by 2050 Approaching temperature limit of 2 C Carbon storage in agricultural soils offers potential

3 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

4 Dairy production and the carbon cycle CO 2 CO 2 CO 2 CH 4 CH 4 Organic C Organic C Organic C Fossil C Fossil C Millions of years Centuries to Decades Now

5 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 CO 2 emissions (The 4 Initiative) Long term global warming impacts hidden by short term solutions? (Jørgensen and Hauschild, 2013)

6 Rad. forc. (mw/m2) Rad. forc. (mw/m2) Climate impact of CO 2 and CH 4 Radiative forcing of one million tonnes of CO 2 Radiative forcing of one million tonnes of CH Year Year Persson et al (based on AR5, IPCC 2013)

7 Rad. forc. (mw/m2) Rad. forc. (mw/m2) Climate impact of CO 2 and CH 4 Radiative forcing of one million tonnes of CO 2 Radiative forcing of one million tonnes of CH DT Year Year DT Persson et al (based on AR5, IPCC 2013)

8 Biogenic versus fossil CH 4 CO 2 Atmospheric CH 4 is broken down to CO 2 CH 4 CH 4 Short term C cycle excluded CO 2 from biogenic CH 4 excluded ( ) Organic C Long term C cycle included CO 2 from fossil CH 4 included ( ) Fossil C

9 Case study Aim Determine the importance of carbon sequestration regarding the GWP of dairy production at various time scales

10 Method grass based [Farm A] vs maize based [Farm B] Farm A [13] Farm B [27] Land area [ha] Grassland [%] Maize land [%] 1 32 Dairy cows [#] FPCM [kg cow -1 yr -1 ] 8,047 9,082 FPCM [kg ha -1 yr -1 ] 13,449 18,361 FADN, 2011;2012;2013 How does C seq. affect the GWP of the farms over time? How does C seq. affect the comparison between farms?

11 Cradle-to-farm gate analysis Fertilizers pesticides, fuels Dairy husbandry Roughage Manure Milk Processing Retail Consumption Feed & food Maize Grass Cows Fattening CO 2 ; CH 4 ; N 2 O

12 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

13 Results pulse of emission (per ton fat-and-protein-corrected milk) GWP (100 yrs) / t FPCM Farm A (grass) 1139 kg CO 2 eq Farm B (maize) 1078 kg CO 2 eq

14 Results pulse of emission (per ton fat-and-protein-corrected milk) GWP (100 yrs) / t FPCM Farm A (grass) (kg CO 2 eq) Excl C seq % Incl C seq (t 100 ) % Incl C seq (t 20 ) % 100 Farm B (maize) Excl C seq 1078 Incl C seq (t 100 ) 1024 Incl C seq (t 20 )

15 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 CO 2 per year; DT C lower with C-seq compared to without C-seq

16 Results continuous emission (per ton fat-and-protein-corrected milk yr -1 ) Excl C seq. Incl C seq. 100 RF per ton FPCM of Farm A (grass) relative to that of Farm B (maize)

17 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

18 Thank you for your attention