Sources of uncertainty in the IPCC Tier 2 Canadian livestock model

2011 ◽  
Vol 150 (5) ◽  
pp. 556-569 ◽  
Author(s):  
Y. KARIMI-ZINDASHTY ◽  
J. D. MACDONALD ◽  
R. L. DESJARDINS ◽  
D. E. WORTH ◽  
J. J. HUTCHINSON ◽  
...  

SUMMARYEstimates of uncertainties are essential when comparing the greenhouse gas (GHG) emissions from a variety of sources. Monte Carlo Simulation (MCS) was applied to estimate the uncertainties in methane emissions and the methane emission intensities from livestock in Canada, calculated using the Intergovernmental Panel on Climate Change (IPCC) methodology. National methane emissions from enteric fermentation and manure management in 2008 were 21·2 and 4·3 Teragram CO2 equivalents (Tg CO2e) with uncertainties of 38 and 73%, respectively. The methane emission intensities (kg of CO2e per kg of live animal weight) were 5·9, 0·9 and 4·9 from Canadian beef, swine and lamb, respectively, with overall uncertainties of 44, 99 and 101%, defined as the 95% confidence interval relative to the mean. A sensitivity analysis demonstrated that IPCC default parameters such as the methane conversion rate (Ym), the coefficient for calculating net energy for maintenance (Cfi) and the methane conversion factor (MCF) were the greatest sources of uncertainty. Canadian agricultural methane emissions are usually calculated by province and by animal subcategories. However, the IPCC default parameters can be assumed to be correlated among regions and animal subcategories; therefore values are assigned at the national scale for the main cattle categories (dairy and non-dairy cattle). When it was assumed that these parameters were uncorrelated at the regional scale, the overall uncertainties were reduced to 20 and 48% for enteric fermentation and manure management, respectively, and assuming that parameters were uncorrelated at the animal subcategory scale reduced uncertainties to 13 and 41% for enteric fermentation and manure management, respectively. When the uncertainty is assigned at the most disaggregated level, even doubling the uncertainty of key parameters such as Ym and Cfi, only increased the national uncertainties to 22 and 52% for enteric fermentation and manure management, respectively. The current analysis demonstrated the importance of obtaining parameters specific to regions and animal subcategories in order to estimate GHG emissions more accurately and to reduce the uncertainties in agricultural GHG inventories. It also showed that assumptions made in the calculation of uncertainties can have a large influence on the uncertainty estimates.

2005 ◽  
Vol 85 (4) ◽  
pp. 501-512 ◽  
Author(s):  
J. A. Basarab ◽  
E. K. Okine ◽  
V. S. Baron ◽  
T. Marx ◽  
P. Ramsey ◽  
...  

This study determined methane emissions from enteric fermentation in Alberta’s beef cattle population by using three methodologies: (1) Intergovernmental Panel on Climate Change (IPCC), Tier 2 guidelines for cattle, (2) actual methane emission factors, expressed as a percentage of gross energy intake, from Canadian research trials and; (3) CowBytes© plus the basic equation developed by Blaxter and Clapperton (1965). Methane emissions, in carbon dioxide equivalents (CO2-E), from Alberta’s beef cattle were determined for 1990, 1996 and 2001. Census of Agriculture numbers for Alberta (Statistics Canada; www.statcan.com) were used and beef cattle were subdivided into 31 distinct categories based on animal type, physiological status, gender, weight, growth rate, activity level and age. Emission of greenhouse gases (GHG) from Alberta ’s beef cattle population, based on IPCC Tier 2 guidelines, were 4.93, 6.57 and 7.01 Mt CO2-E yr-1 in 1990, 1996 and 2001, respectively. Emissions based on methane emission factors from Canadian research trials were 6.23, 8.26 and 8.77 Mt CO2-E yr-1 in 1990, 1996 and 2001, respectively. Estimated methane emissions based on CowBytes© and Blaxter and Clapperton’s (1965) equation were 6.24, 8.35 and 8.94 Mt CO2-E yr-1 in 1990, 1996 and 2001, respectively. The IPCC Tier 2 values were 25.2–26.5% lower than the GHG emissions calculated using emission factors from western Canadian research and 26.7–27.6% lower than GHG emissions calculated from CowBytes© and Blaxter and Clapperton’s equation. IPCC Tier 1 values, which were calculated by multiplying total beef cattle in Alberta by four single value emission factors (beef cows = 72 kg CH4 yr-1; bulls = 75 kg CH4 yr-1; replacement heifers = 56 kg CH4 yr-1; calves, steer and heifer calves for slaughter = 47 kg CH4 yr-1), were 4.83, 6.40 and 6.83 Mt CO2-E in 1990, 1996 and 2001, respectively. Thus, IPCC Tier 1 GHG emissions from enteric fermentation in beef cattle were 2.0–2.7, 28.6–29.1 and 29.2–31.0% lower than those calculated from IPCC Tier 2, western Canadian research trials, and CowBytes© plus Blaxter and Clapperton’s equation, respectively. These results reflect the uncertainty associated with estimating methane emissions from enteric fermentation in cattle and suggest that further research is required to improve the accuracy of methane emissions, particularly for beef cows in their second and third trimester of pregnancy and fed in confinement. They also indicate that a more robust methodology may be to combine CowBytes© predicted dry matter intake with regional specific methane emission factors, where methane loss is expressed as a percentage of gross energy intake. Key words: Cattle, enteric fermentation, greenhouse gas, methane


Author(s):  
Pete Smith ◽  
Dave Reay ◽  
Jo Smith

Agriculture is the largest anthropogenic source of methane (CH 4 ), emitting 145 Tg CH 4  y −1 to the atmosphere in 2017. The main sources are enteric fermentation, manure management, rice cultivation and residue burning. There is significant potential to reduce CH 4 from these sources, with bottom-up mitigation potentials of approximately 10.6, 10, 2 and 1 Tg CH 4  y −1 from rice management, enteric fermentation, manure management and residue burning. Other system-wide studies have assumed even higher potentials of 4.8–47.2 Tg CH 4  y −1 from reduced enteric fermentation, and 4–36 Tg CH 4  y −1 from improved rice management. Biogas (a methane-rich gas mixture generated from the anaerobic decomposition of organic matter and used for energy) also has the potential to reduce unabated CH 4 emissions from animal manures and human waste. In addition to these supply side measures, interventions on the demand-side (shift to a plant-based diet and a reduction in total food loss and waste by 2050) would also significantly reduce methane emissions, perhaps in the order of greater than 50 Tg CH 4  y −1 . While there is a pressing need to reduce emissions of long-lived greenhouse gases (CO 2 and N 2 O) due to their persistence in the atmosphere, despite CH 4 being a short-lived greenhouse gas, the urgency of reducing warming means we must reduce any GHG emissions we can as soon as possible. Because of this, mitigation actions should focus on reducing emissions of all the three main anthropogenic greenhouse gases, including CH 4 . This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part1)'.


2018 ◽  
Vol 61 (3) ◽  
pp. 1121-1131 ◽  
Author(s):  
Yuanqing Zhou ◽  
Hongmin Dong ◽  
Hongwei Xin ◽  
Zhiping Zhu ◽  
Wenqiang Huang ◽  
...  

Abstract. China raises 50% of global live pigs. However, few studies on the carbon footprint (CF) of large-scale pig production based on China’s actual production conditions have been carried out. In this study, life cycle assessment (LCA) and actual production data of a typical large-scale pig farm in northern China were used to assess the greenhouse gas (GHG) emissions or CF associated with the whole process of pig production, including feed production (crop planting, feed processing, and transportation), enteric fermentation, manure management, and energy consumption. The results showed a CF of 3.39 kg CO2-eq per kg of live market pig and relative contributions of 55%, 28%, 13%, and 4% to the total CF by feed production, manure management, farm energy consumption, and enteric fermentation, respectively. Crop planting accounted for 66% of the feed production CF, while feed processing and transportation accounted for the remaining 34%. Long-distance transport of semi-raw feed materials caused by planting-feeding separation and over-fertilization in feed crop planting were two main reasons for the largest contribution of GHG emissions from feed production to the total CF. The CF from nitrogen fertilizer application accounted for 33% to 44% of crop planting and contributed to 16% of the total CF. The CF from the transport of feed ingredients accounted for 17% of the total CF. If the amount of nitrogen fertilizer used for producing the main feed ingredients is reduced from 209 kg hm-2 (for corn) and 216 kg hm-2 (for wheat) to 140 kg hm-2 (corn) and 180 kg hm-2 (wheat), the total CF would be reduced by 7%. If the transport distance for feed materials decreased from 325 to 493 km to 30 km, along with reducing the number of empty vehicles for transport, the total CF would be reduced by 18%. The combined CF mitigation potential for over-fertilization and transport distance is 26%. In addition, the use of pit storage, anaerobic digestion, and lagoon for manure management can reduce GHG emissions from manure management by 76% as compared to the traditional practice of pit storage and lagoon. This case study reveals the impact of planting-feeding separation and over-fertilization on the CF of the pig supply chain in China. The manure management practice of pit storage, anaerobic digestion, and lagoon is much more conductive to reducing the CF as compared to the traditional practice of pit storage and lagoon. Keywords: Greenhouse gas, Life cycle assessment, Mitigation, Pig.


2008 ◽  
Vol 48 (2) ◽  
pp. 38 ◽  
Author(s):  
H. G. van der Meer

This paper focuses on improvements to livestock manure management to reduce environmental pollution and emission of greenhouse gases (GHG). Livestock manures contain large amounts of plant nutrients and organic matter (OM). Structural changes to livestock production and ample supply of cheap chemical fertilisers have decreased the interest and possibilities of farmers in using manure for the fertilisation of crops and grasslands and maintenance of soil fertility. As a result, many livestock producers dispose of manure as cheaply as possible causing serious pollution of soil, water and atmosphere. In addition, livestock production systems contribute to climate change by emission of the GHG carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Careful recycling of livestock manures to fertilise crops and grasslands and improve soil fertility is considered the most suitable and cost-effective option for environmentally friendly disposal. Manure management legislation in The Netherlands is described to explain the principles. These include complete collection of faeces and urine of confined livestock, adaptation of the period and rate of manure application to the N and P requirements of crops, and use of manure collection, storage and application techniques aiming at low ammonia (NH3) losses. Effects of sustainable manure management on GHG emissions are described. Optimising the period, rate and technique of manure application to crops and grassland causes effective utilisation of manure N and reduces direct and indirect losses of N2O. In addition, effective recycling of manure nutrients and OM allows a reduction in the use of chemical fertilisers and fossil energy and contributes to the maintenance or improvement of the carbon content of agricultural ecosystems. The relatively high costs of sustainable manure management stimulate farmers to optimise feed conversion and minimise manure production per unit of product by good livestock feeding and management practices. High feed conversion efficiency reduces CH4 emission by enteric fermentation and may reduce feed imports and related GHG emissions. In addition, it is shown that livestock categories differ widely in feed conversion efficiency and N and P excretion per unit of product. Finally, anaerobic digestion of livestock slurries provides a valuable energy source and reduces CH4 emission of stored slurry and, possibly, N2O emission after field application of the slurry.


2014 ◽  
Vol 94 (1) ◽  
pp. 155-173 ◽  
Author(s):  
Susantha Jayasundara ◽  
Claudia Wagner-Riddle

Jayasundara, S. and Wagner-Riddle, C. 2014. Greenhouse gas emissions intensity of Ontario milk production in 2011 compared with 1991. Can. J. Anim. Sci. 94: 155–173. For identifying opportunities for reducing greenhouse gas (GHG) emissions from milk production in Ontario, this study analyzed GHG intensity of milk [kg CO2 equivalents kg−1 fat and protein corrected milk (FPCM)] in 2011 compared with 1991 considering cow and crop productivity improvements and management changes over this period. It also assessed within-province variability in GHG intensity of milk in 2011 using county-level data related to milk production. After allocating whole-farm GHG emissions between milk and meat using an allocation factor calculated according to the International Dairy Federation equation, GHG intensity of Ontario milk was 1.03 kgCO2eq kg−1 FPCM in 2011, 22% lower than that in 1991 (1.32 kg CO2eq kg−1 FPCM). Greenhouse gas sources directly associated with dairy cattle decreased less (21 and 14% for enteric fermentation and manure management, respectively) than sources associated with feed crop production (30 to 34% for emissions related to N inputs and farm-field work). Proportions of GHG contributed from different life cycle activities did not change, with enteric fermentation contributing 46%, feed crop production 34%, manure management 18% and milking and related activities 2%. Within province, GHG intensity varied from 0.89 to 1.36 kg CO2eq kg−1 FPCM, a variation inversely correlated with milk productivity per cow (kg FPCM sold cow−1 year−1). The existence of a wide variation is strong indication for potential further reductions in GHG intensity of Ontario milk through the identification of practices associated with high efficiency.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 136-136
Author(s):  
Ridha Ibidhi ◽  
Tae Hoon Kim ◽  
Rajaraman Bharanidharan ◽  
Krishnaraj Thirugnanasambantham ◽  
Kyoung Hoon Kim

Abstract In the context of global climate change, carbon footprint (CF) becomes an important sustainability indicator for dairy production systems. To mitigation the CF of the dairy sector, insight into greenhouse gases (GHG) emissions from individual farms is required. The objective of this study was to determine the primary contributors to GHG emissions at the farm-gate level, expressed as a carbon dioxide equivalents (CO2-eq), to produce one kg of fat-and protein corrected milk (FPCM). Primary data about farms’ management and feeding practices were collected from twelve dairy farms that belong to Gyeonggi-do province, which represent the most important region for milk production in South Korea. Allocation of GHG emissions between meat and milk was assessed as a physical allocation, 98% allocated to milk and 2% to meat (surplus of calves and culled cows). The CF of the evaluated farms averaged to 0.61 CO2-eq/kg of FPCM and ranged from 0.49 to 0.78 CO2-eq/kg of FPCM. Results indicated that the largest source of GHG comes mostly from enteric fermentation (83%), followed by manure management (6%), manure and fertilizer land application (8%) and energy consumption (3%). By type of gas emitted, methane accounted for 86% of total emissions, originating from enteric fermentation and manure management. Nitrous oxide and carbon dioxide accounted for 11.6 % and 2.8% of total GHG emissions, respectively. Lactating cows contributed by 70% of total GHG emissions, whereas dry cows, heifers and calves contributed by 5, 22 and 3%, respectively. Differences in GHG emissions from the evaluated farms could be explained by differences in feed quality and management practices through manure and fertilizers application on cropland. This study contributes to identify the main sources of GHG production in dairy farms, which can help to define mitigation strategies towards the transition to neutral carbon emissions of the dairy sector.


2015 ◽  
Vol 13 (4) ◽  
pp. e06SC05 ◽  
Author(s):  
José Pereira ◽  
Henrique Trindade

<p>The aim of this study was evaluate the relationship between the intensity of milk production for a wide range of Portuguese commercial cattle farms and NH<sub>3</sub> and greenhouse gas (GHG) emissions from manure management and enteric fermentation. A survey was carried out at 1471 commercial dairy cattle farms (Holstein-Friesian) and the NH<sub>3</sub>, N<sub>2</sub>O and CH<sub>4</sub> emissions at each stage of manure management were estimated as well as CH<sub>4</sub> losses from enteric fermentation. Gaseous emissions were estimated by a mass flow approach and following the recommendations of IPCC guidelines. The manure management and enteric fermentation in a typical Portuguese cattle farm contributes with 7.5±0.15 g N/L milk produced as NH<sub>3</sub> and 1.2±0.22 kg CO<sub>2</sub> equivalent per litre of milk as GHG. Increasing milk production will significantly reduce NH<sub>3</sub> and GHG emissions per litre of milk produced. It can be concluded that a win-win strategy for reducing NH<sub>3</sub> and GHG emissions from dairy cattle farms will be the increase of milk production on these farms. This goal can be achieved by implementing animal breeding programs and improving feed efficiency in order to increase productivity.</p>


2020 ◽  
Author(s):  
Nathalia dos Reis Vechi ◽  
Antonio Delre ◽  
Charlotte Scheutz

&lt;p&gt;One of the largest methane anthropogenic sources worldwide is livestock production. In Denmark, this contribution reached 81.1% of total anthropogenic methane, divided into both enteric fermentation and manure management emissions (Nielsen et al., 2019). Numerous factors can influence methane emissions from livestock production. The development of strategies to measure and monitor this anthropogenic activity allows the identification of efficient mitigation actions. The dynamic tracer gas dispersion method (TDM) is a ground-based remote sensing method, which combines a controlled release of tracer gas from the target source with concentration measurements downwind of the same source. TDM has been compared to other remote sensing techniques and widely applied for methane quantification from many facilities (Samuelsson et al., 2018). Previous studies found that this method is very likely to reached up to only 20% of error (Fredenslund et al., 2019). For livestock methane quantification, TDM has been used before releasing a strong greenhouse gas (SF&lt;sub&gt;6&lt;/sub&gt;) with mostly stationary point sampling setup. The aim is to verify the suitability of the method for these facilities and identify the differences between farming approaches. Furthermore, the comparison of the measured emissions with inventory estimation could show the accuracy of the later.&lt;/p&gt;&lt;p&gt;This study uses acetylene as tracer gas and measurements performed with a fast responding and highly sensitive gas analyzer by Picarro. On this project, emissions from six livestock facilities (dairy cows and swine production) were investigated along one year.&lt;/p&gt;&lt;p&gt;Dairy farms were the largest methane emitters per head (Around 40 gCH&lt;sub&gt;4&lt;/sub&gt;/head/h). Results show that management practices might cause different methane emissions from dairy farms. Similar result was observed analyzing emissions from pig facilities (Around 6 gCH&lt;sub&gt;4&lt;/sub&gt;/head/h), with an influence of animal life stage. The sow&amp;#8217;s farm had the highest methane emission factor when compared to fattening pigs, while manure acidification treatment might have a positive impact on reducing methane emission.&lt;/p&gt;&lt;p&gt;The successful application in this study of the TDM showed that this method is a valuable tool to support Danish farming strategies to meet ambitious GHG emission reduction targets.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Fredenslund, A. M., Rees-White, T. C., Beaven, R. P., Delre, A., Finlayson, A., Helmore, J., &amp;#8230; Scheutz, C. (2019). Validation and error assessment of the mobile tracer gas dispersion method for measurement of fugitive emissions from area sources. Waste Management, 83, 68&amp;#8211;78.&lt;/p&gt;&lt;p&gt;Nielsen, O.-K., Plejdrup, M. S., Winther, M., Nielsen, M., Gyldenk&amp;#230;rne, S., Mikkelsen, M. H., &amp;#8230; Hansen, M. G. (2019). Denmark&amp;#8217;s National Inventory Report 2019 (Emission I).&lt;/p&gt;&lt;p&gt;Samuelsson, J., Delre, A., Tumlin, S., Hadi, S., Offerle, B., &amp; Scheutz, C. (2018). Optical technologies applied alongside on-site and remote approaches for climate gas emission quantification at a wastewater treatment plant. Water Research, 131, 299&amp;#8211;309.&lt;/p&gt;


2013 ◽  
Vol 22 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Tom Misselbrook ◽  
Agustin Del Prado ◽  
David Chadwick

Modern dairy production is inevitably associated with impacts to the environment and the challenge for the industry today is to increase production to meet growing global demand while minimising emissions to the environment. Negative environmental impacts include gaseous emissions to the atmosphere, of ammonia from livestock manure and fertiliser use, of methane from enteric fermentation and manure management, and of nitrous oxide from nitrogen applications to soils and from manure management. Emissions to water include nitrate, ammonium, phosphorus, sediment, pathogens and organic matter, deriving from nutrient applications to forage crops and/or the management of grazing livestock. This paper reviews the sources and impacts of such emissions in the context of a forage-based dairy farm and considers a number of potential mitigation strategies, giving some examples using the farm-scale model SIMSDAIRY. Most of the mitigation measures discussed are associated with systemic improvements in the efficiency of production in dairy systems. Important examples of mitigations include: improvements to dairy herd fertility, that can reduce methane and ammonia emissions by up to 24 and 17%, respectively; diet modification such as the use of high sugar grasses for grazing, which are associated with reductions in cattle N excretion of up to 20% (and therefore lower N losses to the environment) and potentially lower methane emissions, or reducing the crude protein content of the dairy cow diet through use of maize silage to reduce N excretion and methane emissions; the use of nitrification inhibitors with fertiliser and slurry applications to reduce nitrous oxide emissions and nitrate leaching by up to 50%. Much can also be achieved through attention to the quantity, timing and method of application of nutrients to forage crops and utilising advances made through genetic improvements.


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