Reducing methane on-farm by feeding diets high in fat may not always reduce life cycle greenhouse gas emissions

2013 ◽  
Vol 19 (1) ◽  
pp. 69-78 ◽  
Author(s):  
S. Richard O. Williams ◽  
Peter D. Fisher ◽  
Tony Berrisford ◽  
Peter J. Moate ◽  
Keith Reynard
2013 ◽  
Vol 53 (6) ◽  
pp. 495 ◽  
Author(s):  
Philippa M. Brock ◽  
Phillip Graham ◽  
Patrick Madden ◽  
Douglas J. Alcock

The use of Life Cycle Assessment (LCA) to determine environmental impacts of agricultural production, as well as production by other industry sectors has increased. LCA provides an internationally accepted method to underpin labelling and marketing of agricultural products, a valuable tool to compare emissions reduction strategies and a means to identify perverse policy outcomes. A single-issue LCA focussing on greenhouse gas emissions was conducted to determine the emissions profile and carbon footprint of 19-micron wool produced in the Yass Region on the Southern Tablelands of New South Wales. Greenhouse gas emissions (in carbon dioxide equivalents; CO2-e) from the production of all enterprise inputs and from the production of wool on-farm were included. Total emissions were found to be 24.9 kg CO2-e per kg of greasy wool at the farm gate, based on a 4941 breeding ewe enterprise on 1000 ha, with a total greasy wool yield of 65.32 t per annum. The co-products included 174 t sheep meat as liveweight from wethers and cull ewes plus 978 maiden ewes sold off-farm as replacement stock. Total emissions from all products grown on 1000 ha were 2899 t CO2-e per annum. The relative contribution of greenhouse gas emissions from different components of the production system was determined. Direct emission of methane on-farm (86% of total) was the dominant emission, followed by nitrous oxide emitted from animal wastes directly (5%) and indirectly (5%), and decomposition of pasture residue (1%). Only 2% of total emissions were embodied in farm inputs, including fertiliser. The emissions profile varied according to calculation method and assumptions. Enteric methane production was calculated using five recognised methods and results were found to vary by 27%. This study also showed that calculated emissions for wool production changed substantially, under an economic allocation method, by changing the enterprise emphasis from wool to meat production (41% decrease) and by changing wool price (29% variability), fibre diameter (23% variability) and fleece weight (11% variability). This paper provides data specific to the Yass Region and addresses broader methodological issues, to ensure that future livestock emissions calculations are robust.


2008 ◽  
Vol 48 (3) ◽  
pp. 375 ◽  
Author(s):  
Tim Grant ◽  
Tom Beer

The life cycle assessment component of this multi-institutional project determined greenhouse gas emissions in pre-farm, on-farm and post-farm activities involved in the use of maize for the manufacture of corn chips. When the emissions were expressed in terms of carbon dioxide-equivalents (CO2-e), pre-farm emissions comprised ~6% of the life cycle emissions, on-farm activities comprised ~36% and post-farm activities accounted for ~58% of life cycle greenhouse gas emissions. We used one 400 g packet of corn chips as the functional unit. The single largest source of greenhouse emissions was the emission of nitrous oxide on the farm as a result of fertiliser application (0.126 kg CO2-e per packet). The next largest was electricity used during the manufacture of the corn chips (0.086 kg CO2-e per packet). The manufacture of the packaging (box plus packet, being 0.06 kg CO2-e) was the next largest source and then the oil for frying the corn chips (0.048 kg CO2-e per packet). Greenhouse gas emissions from fertiliser application were primarily nitrous oxide (N2O), which has a global warming potential of 310 kg CO2-e/kg N2O. In typical irrigated farm systems, these emissions, when converted to CO2-e, are almost three times more than the greenhouse gas emissions that result from energy used to pump water. However, pumping irrigation water from deep bores currently produces greenhouse gas emissions that are almost three times those from irrigation using surface waters. Greenhouse gas emissions from the use of tractors on typical farms are about one-third of the emissions from pumping water. Farm management techniques can be used to increase soil carbon and reduce greenhouse gas emissions. If farms that currently burn stubble were to implement stubble incorporation then, in the absence of other changes to the supply chain, they will achieve a 30% reduction in emissions from ‘cradle to farm-gate’. In absolute terms, when the soil carbon dioxide is included (even though soil carbon dioxide in this instance is not counted as a greenhouse gas in national and international greenhouse gas inventories), our measurements indicate that carbon dioxide and greenhouse gas emissions from farms that produce maize using stubble incorporation are 56% lower than emissions from farms that burn their stubble. The pre-farm and on-farm operations add $0.40 value per kg of CO2-e greenhouse gas emitted. Post-farm processing added $2 value per kg of CO2-e greenhouse gas emitted. Processing maize for corn chips emitted more greenhouse gases than processing the same amount of corn for starch or ethanol.


Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Florian Stuhlenmiller ◽  
Steffi Weyand ◽  
Jens Jungblut ◽  
Liselotte Schebek ◽  
Debora Clever ◽  
...  

Modern industry benefits from the automation capabilities and flexibility of robots. Consequently, the performance depends on the individual task, robot and trajectory, while application periods of several years lead to a significant impact of the use phase on the resource efficiency. In this work, simulation models predicting a robot’s energy consumption are extended by an estimation of the reliability, enabling the consideration of maintenance to enhance the assessment of the application’s life cycle costs. Furthermore, a life cycle assessment yields the greenhouse gas emissions for the individual application. Potential benefits of the combination of motion simulation and cost analysis are highlighted by the application to an exemplary system. For the selected application, the consumed energy has a distinct impact on greenhouse gas emissions, while acquisition costs govern life cycle costs. Low cycle times result in reduced costs per workpiece, however, for short cycle times and higher payloads, the probability of required spare parts distinctly increases for two critical robotic joints. Hence, the analysis of energy consumption and reliability, in combination with maintenance, life cycle costing and life cycle assessment, can provide additional information to improve the resource efficiency.


Sign in / Sign up

Export Citation Format

Share Document