Peeling Away the Layers of Pork's Carbon FootprintPeeling Away the Layers of Pork's Carbon Footprint
Pork Checkoff's Life Cycle Assessment of greenhouse gas emissions is entering the final phase and the outcome will be a producer-friendly, greenhouse gas prediction tool
March 15, 2010
Pork Checkoff's Life Cycle Assessment of greenhouse gas emissions is entering the final phase and the outcome will be a producer-friendly, greenhouse gas prediction tool.
It is a rare day when the daily news headlines do not trumpet concerns about climate change, greenhouse gas threats or the need for carbon footprinting. It's a global phenomenon.
In an effort to get out ahead of the pressures to measure the impact the pork industry is having on the environment, the National Pork Board commissioned the University of Arkansas' Applied Sustainability Center to conduct a life cycle assessment (LCA) of the U.S. pork supply chain.
The goal of the three-phase Carbon Footprint Initiative is to define with clarity and precision the greenhouse gas (GHG) emissions associated with the live swine production portion of the pork chain.
An intermediate step is to complete what is termed a “scan level” LCA that quantifies in broad terms the GHG emissions for producing a serving of pork. The LCA encompasses the crop production required to raise the feed ingredients; the delivery of hogs to the processor; the processing, packaging and distribution of the product to the retailer; refrigeration; preparation and consumption of the pork product; and the disposal of the packaging at the end of the chain.
For the scan-level LCA, the Arkansas group broadly divided the pork chain into eight stages, each receiving a separate analysis that was combined to provide the entire life-cycle footprint. The eight stages are: feed production, live swine production, delivery to the processor, processing, packaging, distribution, retail, and consumption/disposal (of packaging).
Overall, the LCA accounts for all activities performed in support of pork production and delivery and the raw materials used in the effort, such as fertilizer production; fuel use in production, delivery, and packaging; electricity transmission; and distribution losses. To complete the cycle, the impacts of pork distribution and refrigeration, as well as product losses through the supply chain, were calculated.
“GHG emissions are commonly defined in terms of the cumulative global warming potential of all greenhouse gases emitted for a system or product — in this case, across the supply chain necessary to provide pork products to the consumer,” states the abstract describing the study, “National Scan-Level Carbon Footprint Study for Production of U.S. Swine.”
The greenhouse gases of most concern are carbon dioxide (CO2), methane (CH4), nitrous oxide (primarily from crop production) and common refrigerants. From a global warming perspective, GHGs are reported in terms of carbon dioxide equivalents (CO2e), derived by converting non-CO2 gas emissions to an “equivalent global warming potential (GWP)” quantity of CO2.
In the end, the analysis was carried out for the functional unit against which the total GHG expenditure was measured — and that unit was defined as the consumption of one 4-oz. serving of boneless pork.
“Fundamentally, there isn't much GHG emissions data for the U.S. pork industry,” explains Allan Stokes, director of environmental programs at the National Pork Board. “Most of the work and analysis that has been done on air emissions has not been done on greenhouse gases. Rather, it's been done on odors, particulates, hydrogen sulfides and ammonia.”
Therefore, phase one of the life-cycle assessment was to conduct an extensive literature review spearheaded by the Arkansas group. Researchers studied what is known about GHG emissions, globally, through all segments of the pork chain.
In phase two, raw data was solicited from a broad array of industry experts and publications, plus regionally specific data for crops and weather patterns.
“This report (drafted by the University of Arkansas Applied Sustainability Center) summarizes a scan-level carbon footprint analysis for a single serving of boneless pork prepared for consumption through evaluation of GHG emissions across the entire (pork) production and delivery system with relatively low resolution and high data aggregation. That is, it is not for a specific production system, but represents an overall average of U.S. production, processing and distribution systems.
“The available life-cycle data by production stage, and the methodology for calculation of the carbon footprint, is described. It was found that the major impacts of swine production occur in crop production, manure management, retail distribution and consumption,” the report states.
“It's a five-mile-high analysis with a very high degree of aggregation of data across the entire pork chain — from crops in the field, to cooking, to the consumer eating and to disposing of the packaging,” Stokes explains. “Fundamentally, it shows that crops are not an insignificant contributor to the GHG emissions for the whole pork chain.
“The overall estimate of the carbon footprint for preparation and consumption of one 4-oz. serving (of boneless pork) was found to be 2.2 lb. CO2e with a 95% confidence band from 1.8 to 2.7 lb. CO2e. They base this (estimate) on the productive life span of a sow, rather than look at ‘per pig’ space or other basis,” he adds.
The underlying assumptions included:
3.5 litters/sow lifetime;
268 lb. market weight;
Carcass conversion (yield) of 75% of live weight;
Boneless conversion of 65% of carcass; and
Typical corn, soybean meal, dried distillers' grains with soluble diets.
In addition, GHG emissions from manure were calculated based on Intergovernmental Panel on Climate Change (IPCC), American Society of Engineers manure management guidelines and the Pork Industry Handbook specifications for ventilation and heating. The biogenic carbon portion — an estimate of crop sequestration and animal respiration — were excluded from the LCA. Other industry sources provided transport, packaging and packaging disposal information.
The preliminary results from the scan-level LCA break down the contribution (of various stages of production or production units) to an “emissions burden” — the 2.2 lb. CO2e per 4-oz. serving — as follows:
13.6% from breeding and lactating sows, including feed and manure handling;
53% from nursery-to-finish (including feed and manure handling);
6.7% from processing and packaging;
14% from retail (electricity and refrigerants; and
13% from the consumer (including refrigeration, preparation and packaging disposal).
The breakout will vary according to the type of manure management program and region of the country, Stokes says. As Figures 1 and 2 show, a lagoon manure management system has a higher GHG than a deep-pit manure management system.
The regional variability, primarily driven by the manure management program shown in Figure 3, compares the East, West and upper Midwest regions. “Temperature and climate conditions have a lot of impact on generating the GHG (levels),” he adds.
GHG Calculator Available Soon
The third and final phase of the Pork Board's Carbon Footprint Initiative focuses on the live hog production portion of the pork supply chain.
“We will be developing a process model for GHG emissions specific to live swine production, where a producer could sit down to a fairly user-friendly computer program and plug in their variables, such as their nutrition programs and regimens, manure handling methods and other types of attributes, to get a fairly specific, detailed picture of what their GHG emission profile would look like. In turn, they will be able to identify their ‘hot spots’ and decide whether there is anything they want to do, or can do, about those,” Stokes explains. “More importantly, when the model is fully functional, it will give a producer a breakdown of different components of their overall emissions of GHGs.”
In addition to the producer benefits, these hot-spot areas will help guide Pork Checkoff research needs, as well as educational and outreach programs to get information to producers, he says.
“In the long run, it will help us evaluate some new techniques and processes that are coming along. We can factor those into the model and figure out what their impact would be,” Stokes explains.
This phase has taken a bit longer than anticipated. The good news is the model will be much more robust, with a higher degree of precision, than originally planned. And, it will be readily updated as more and better information is available.
“The model is designed as a producer tool that will help identify and benchmark what the carbon footprint for the (pork) industry is in generalized, average production (terms), but it will also provide a baseline carbon footprint for a (specific) production operation,” he adds.
Equally important, the model will allow the user to plug in various components and changes to document the positive changes that have been made since the 1970s or 1980s, for example.
“We certainly have gotten more efficient in feed conversion and faster growth rates, so fundamentally, we are using less feed to get the same weight animal to market sooner,” Stokes reinforces. “All of that translates into less energy used and a more favorable GHG emission profile or carbon footprint. We can take credit where credit is due.”
What it is, What it's not
“The National Pork Board's over-riding motivation for doing the Carbon Footprint Initiative was to understand where our producers could realize benefits from improved, more efficient operations that could improve their bottom lines by reducing input costs,” Stokes continues. “Secondarily, the goal is to address the environmental side that will help align our producers and our products with consumers and their expectations and demands. This effort is fully consistent with the pork industry's ‘We Care’ initiative, and further demonstrates to consumers that the industry has an ongoing commitment of responsibility in key areas, such as the environment.
“This has never been intended to produce a bright-line number that a producer must meet; it's more a profile of what an operation looks like, to understand where their opportunities are. Nothing here is meant to dictate what a producer must do,” he says.
The proposed model is designed so producers can input their farm data and generate a report for their use only. “Carbon footprints will not be collected on individual farms or operations,” Stokes assures.
The GHG emissions model will be beta tested in various types of production systems and farms this spring and summer.
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