Pork’s Carbon Footprint - Dr. Gregory Thoma, professor, agriculture chemical engineering, University of Arkansas, Fayetteville, from the Minnesota Pork Congress, January 20-21, 2010, Minneapolis, MN, USA.
Why are we doing the study?What are the system characteristics – what is usedWhat are the impacts associated with each phase (multi faceted)Interpretation of the results into understanding of system in support of action to improve it
Given all of the work in different areas in both LCA we must begin coordinating efforts to make sure that different measurements and standards are comparable.
Need to see this to follow calculaiton
The width of the connecting lines represents the relative contribution from the particular unit to the whole ghgemisssion. The contribution shown in each box is the cumulative contribution from all of the network nodes upstream in the supply chain plus the contribution occurring at that node.
Interesting: feed and retail/consumption are significant; MMS dominates on –farm ghg
Mention comparison to Dalgaard work ==2kg/kg live or about 2.7 kg /dressed carcass; EU 3 ~ 5 kg/kg carcass25% from manure (with credit for avoided inorganic N)
Allocation based on economic research service sector level activity; data from aggregated industry sources
2 points: 1 consumption is >15% of footprint; electricity slightly less efficient than natural gas – grilling seems to be the best.
How sensitive is the result to EF for MMS (ch4 & n2o) & B0Base case is IPCC recommended mean value; high and low 20-50% change depending on parameterRange of EF leads to about 0.75 kg co2e variation or about25%
Northeast same as NC but 8C mean temperature
Differences in manure management and electricity
This is larger then epareoprt national report: it includes crop produciton and processing -> disposal
Have to be cautious in making comparisons with LCAresults; vertical bars 95% CI => statistically indistinguishable
Dr. Gregory Thoma - Pork’s Carbon Footprint
National Scan-level Carbon Footprint Study for Production of US Swine <br />Greg Thoma<br />Jason Frank <br />Charles Maxwell <br />Cash East<br />Darin Nutter<br />Minnesota Pork Congress<br />January 20, 2010 Minneapolis, MN<br />
Calculating a carbon footprint requires:<br />A full system-level accounting of greenhouse gases emitted in association with a product or service<br />Energy consumption<br />Manure & nutrient management<br />The system begins with extraction from nature and includes packaging disposal<br />Life Cycle Assessment is a systems analysis tool commonly used as a framework for these calculations<br />
Life Cycle Analysis - 101<br />Attributes or characteristics of product or process<br />Environmental effects of product or process<br />
Life Cycle Analysis<br />Releases to environment<br />Releases to environment<br />Extractions from environment<br />Outputs<br />Inputs<br /><ul><li>An accounting of inputs and outputs for all stages of a product
Product labels</li></ul>Extractions from environment<br />
Emerging Consensus on LCA Framework<br />Need for comparable metrics that span sectors, industries and geographies<br />Metrics should be grounded in scientific methodologies, namely Life Cycle Assessment<br />Sustainability Metrics, Indicators and Indices must be transparent<br />LCA data (LCI) should be transparent, validated, widely available, inexpensive<br />The same LCA data and models should be used by producers, retailers, policymakers, NGOs and consumers<br />
Outline of Swine LCA:defining the system<br />Goal and Scope<br />Determine GHG1emissionsassociated with delivery of one serving of pork to US consumer.<br />Cradle to grave. From crop production through consumption and package disposal<br />1Greenhouse gases, expressed as CO2 equivalents<br />
Conceptual Farm Model<br />Emissions<br />Emissions<br />Energy<br />Sow Barn:<br />Breeding; Gestation; Lactation<br />Nursery – Finish Barn<br />Energy<br />Finished pigs<br />Gilt<br />Weaned pigs<br />Feed<br />Feed<br />Manure Management<br />Manure Management<br />Emissions; Fertilizer<br />Emissions; Fertilizer<br />Material and energy flows are integrated over a sow’s productive life. The farm gate total consumption of feed and energy required to grow all the litters produced by one sow is allocated to the total finished weight of her litters.<br />
Some Underlying Assumptions<br />9.5 piglets/litter and 3.5 litters per sow<br />Finished live weight: 268 lb<br />Carcass = 0.75 live weight<br />Boneless = 0.65 carcass<br />Typical corn, soy meal, distiller’s grain diets<br />With supplements accounted; 82% digestibility<br />ASABE ‘standard’ manure characteristics1<br />IPCC Tier 2 GHG emission factors for manure systems2<br />Purdue Handbook for ventilation, heating<br />Biogenic Carbon<br />crop sequestration & animal respiration excluded<br />1 American Society of Agricultural Engineers, 2005 ASAE D384.2 MAR2005. <br />2 Dong, H., et al. (2006) Chapter 10 6 IPCC Guidelines for National Greenhouse Gas Inventories.<br />
Some Underlying Assumptions<br />10% waste (spoiled or uneaten) by consumers<br />Economic allocation<br />Feed byproducts<br />Rendering co-products<br />Space allocation<br />Retail<br />In-home<br />
The Big Picture<br />2.2 lb CO2e per 4oz serving (8.8 kg CO2e/kg pork consumed)<br />with a 95% confidence interval from 1.8 to 2.7 lb CO2e. <br />The contribution of emission burden: <br />13.6%: sow barn (including feed and manure handling); <br />53%: nursery to finish (including feed and manure handling); <br />6.7%: processing and packaging; <br />14%: retail (electricity and refrigerants); <br />13%: the consumer (refrigeration and cooking).<br />
Network Diagram - Legend<br />Reference Flow(quantity of material or energy)<br />Process or Material Contributing to Footprint<br />Connecting Line Weight is Proportional to GHG Contribution<br />GHG contribution(cumulative kg CO2e contributed by this branch of the network)<br />
Cradle to grave footprint: Base case: Deep pit <br />This flow is a credit for avoided production of nitrogen fertilizer<br />
Uncertainty<br />All variables have some variability<br />Propagation of uncertainty performed by Monte Carlo simulation<br />600 runs, random variates from log normal pdf<br />Pit System: 7.1 kg CO2e per kg pork consumed with a 95% confidence band from 5.8 to 8.5 kg CO2e/kg consumed. <br />Anaerobic lagoon: 10.2 kg CO2e/kg boneless pork consumed, with 95% confidence band from 8.22 to 12.65 kg CO2e/kg consumed. <br />
National GHG Impact of Swine Consumption<br />Define regional practice scenario<br />Climate Leaders<br />Determine number of animals raised<br />State level statistics (NASS)<br />Calculate weighted sum of emissions<br />
National Scale Cumulative Impact<br />8.8 kg CO2e/ kg consumed or<br />2.2 lb CO2e / 4 oz serving<br />
Conclusions<br />Manure management is a large opportunity<br />Consumption contributes a significant fraction of the total<br />Fuels and Electricity are important, but not the largest contributors to the overall footprint, but opportunities for increased efficiency <br />Processing is relatively efficient per kg processed, but consumes large amounts of energy.<br />
Future Directions<br />Detailed LCA for live swine production<br />Field to farm gate <br />More granular evaluation of production practices<br />Targeted questionnaire to collect production specific data <br />Identification of opportunities for energy savings and reduction of GHG emissions<br />Process based modules calibrated against reported information<br />