| 1. |
- Flysjö, A., et al.
(författare)
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How does co-product handling affect the carbon footprint of milk? Case study of milk production in New Zealand and Sweden
- 2011
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Ingår i: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 16:5, s. 420-430
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Tidskriftsartikel (refereegranskat)abstract
- Purpose This paper investigates different methodologies of handling co-products in life cycle assessment (LCA) or carbon footprint (CF) studies. Co-product handling can have a significant effect on final LCA/CF results, and although there are guidelines on the preferred order for different methods for handling co-products, no agreed understanding on applicable methods is available. In the present study, the greenhouse gases (GHG) associated with the production of 1 kg of energy-corrected milk (ECM) at farm gate is investigated considering co-product handling. Materials and methods Two different milk production systems were used as case studies in the investigation of the effect of applying different methodologies in coproduct handling: (1) outdoor grazing system in New Zealand and (2) mainly indoor housing system with a pronounced share of concentrate feed in Sweden. Since the cows produce milk, meat (when slaughtered), calves, manure, hides, etc., the environmental burden (here GHG emissions) must be distributed between these outputs (in the present study no emissions are attributed to hides specifically, or to manure which is recycled on-farm). Different methodologically approaches, (1) system expansion (two cases), (2) physical causality allocation, (3) economic allocation, (4) protein allocation and (5) mass allocation, are applied in the study. Results and discussion The results show large differences in the final CF number depending on which methodology has been used for accounting co-products. Most evident is that system expansion gives a lower CF for milk than allocation methods. System expansion resulted in 63- 76% of GHG emissions attributed directly to milk, while allocation resulted in 85-98%. It is stressed that meat is an important by-product from milk production and that milk and beef production is closely interlinked and therefore needs to be considered in an integrated approach. Conclusions To obtain valid LCA/CF numbers for milk, it is crucial to account for by-products. Moreover, if CF numbers for milk need to be compared, the same allocation procedure should be applied. © 2011 Springer-Verlag.
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| 2. |
- Flysjö, A., et al.
(författare)
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The impact of various parameters on the carbon footprint of milk production in New Zealand and Sweden
- 2011
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Ingår i: Agricultural Systems. - : Elsevier BV. - 1873-2267 .- 0308-521X. ; 104:6, s. 459-469
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Tidskriftsartikel (refereegranskat)abstract
- The carbon footprint (CF) of milk production was analysed at the farm gate for two contrasting production systems; an outdoor pasture grazing system in New Zealand (NZ) and a mainly indoor housing system with pronounced use of concentrate feed in Sweden (SE). The method used is based on the conceptual framework of lifecycle assessment (LCA), but only for greenhouse gas (GHG) emissions. National average data were used to model the dairy system in each country. Collection of inventory data and calculations of emissions were harmonised to the greatest extent possible for the two systems. The calculated CF for 1kg of energy corrected milk (ECM), including related by-products (surplus calves and culled cows), was 1.00kg carbon dioxide equivalents (CO2e) for NZ and 1.16kg CO2e for SE. Methane from enteric fermentation and nitrous oxide emissions from application of nitrogen (as fertiliser and as excreta dropped directly on the field) were the main contributors to the CF in both countries. The most important parameters to consider when calculating the GHG emissions were dry matter intake (DMI), emission factor (EF) for methane from enteric fermentation, amount of nitrogen applied and EF for direct nitrous oxide emissions from soils. By changing one parameter at a time within 'reasonable' limits (i.e. no extreme values assumed), the impact on the total CF was assessed and showed changes of up to 15%. In addition, the uncertainty in CF estimates due to uncertainty in EF for methane from enteric fermentation and nitrous oxide emissions (from soil and due to ammonia volatilisation) were analysed through Monte Carlo simulation. This resulted in an uncertainty distribution corresponding to 0.60-1.52kg CO2e kg-1 ECM for NZ and 0.83-1.56kg CO2e kg-1 ECM for SE (in the prediction interval 2.5-97.5%). Hence, the variation within the systems based on the main EF is relatively large compared with the difference in CF between the countries. © 2011 Elsevier Ltd.
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| 3. |
- Henriksson, Maria, et al.
(författare)
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Variation in carbon footprint of milk due to management differences between Swedish dairy farms
- 2011
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 5:9, s. 1474-1484
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Tidskriftsartikel (refereegranskat)abstract
- To identify mitigation options to reduce greenhouse gas (GHG) emissions from milk production (i.e. the carbon footprint (CF) of milk), this study examined the variation in GHG emissions among dairy farms using data from previous CF studies on Swedish milk. Variations between farms in these production data, which were found to have a strong influence on milk CF, were obtained from existing databases of 1051 dairy farms in Sweden in 2005. Monte Carlo (MC) analysis was used to analyse the impact of variations in seven important parameters on milk CF concerning milk yield (energy-corrected milk (ECM) produced and delivered), feed dry matter intake (DMI), enteric CH4 emissions, N content in feed DMI, N-fertiliser rate and diesel used on farm. The largest between-farm variations among the analysed production data were N-fertiliser rate (kg/ha) and diesel used (l/ha) on farm (CV = 31% to 38%). For the parameters concerning milk yield and feed DMI, the CV was approximately 11% and 8%, respectively. The smallest variation in production data was found for N content in feed DMI. According to the MC analysis, these variations in production data led to a variation in milk CF of between 0.94 and 1.33 kg CO2 equivalents (CO2e)/kg ECM, with an average value of 1.13 kg CO2e/kg ECM. We consider that this variation of ±17%, which was found to be based on the used farm data, would be even greater if all Swedish dairy farms were included, as the sample of farms in this study was not totally unbiased. The variation identified in milk CF indicates that a potential exists to reduce GHG emissions from milk production on both the national and farm levels through changes in management. As milk yield and feed DMI are two of the most influential parameters for milk CF, feed conversion efficiency (i.e. units ECM produced/unit DMI) can be used as a rough key performance indicator for predicting CF reductions. However, it must be borne in mind that feeds have different CF due to where and how they are produced. © 2011 The Animal Consortium.
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| 4. |
- Egeskog, Andrea, 1981, et al.
(författare)
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Actions and opinions of Brazilian farmers who shift to sugarcane : an interview-based assessment with discussion of implications for land-use change
- 2016
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Ingår i: Land use policy. - Kidlington : Elsevier. - 0264-8377 .- 1873-5754. ; 57, s. 594-604
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Tidskriftsartikel (refereegranskat)abstract
- Sugarcane ethanol systems can deliver large greenhouse gas emissions savings if emissions associated with land-use change are kept low. This qualitative study documents and analyzes actions and opinions among Brazilian farmers who shift to sugarcane production. Semi-structured interviews were held with 28 actors associated with sugarcane production in three different regions: one traditional sugarcane region and two regions where sugarcane is currently expanding. Most farmers considered sugarcane a land diversification option with relatively low economic risk, although higher risk than their previous land use. Beef production was considered a low-risk option, but less profitable than sugarcane. In conjunction with converting part of their land to sugarcane, most farmers maintained and further intensified their previous agricultural activity, often beef production. Several farmers invested in expanded production in other regions with relatively low land prices. Very few farmers in the expansion regions shifted all their land from the former, less profitable, use to sugarcane. Very few farmers in this study had deforested any land in connection with changes made when shifting to sugarcane. The respondents understand "environmental friendliness" as compliance with the relevant legislation, especially the Brazilian Forest Act, which is also a requirement for delivering sugarcane to the mills. Indirect land-use change is not a concern for the interviewed farmers, and conversion of forests and other native vegetation into sugarcane plantations is uncontroversial if legal. We derive hypotheses regarding farmers' actions and opinions from our results. These hypotheses aim to contribute to better understanding of what takes place in conjunction with expansion of sugarcane and can, when tested further, be of use in developing, e.g., policies for iLUC-free biofuel production.
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| 5. |
- Risberg, Kajsa, et al.
(författare)
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Biogas production from wheat straw and manure : Impact of pretreatment and process operating parameters
- 2013
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 149, s. 232-237
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Tidskriftsartikel (refereegranskat)abstract
- Non-treated or steam-exploded straw in co-digestion with cattle manure was evaluated as a substrate for biogas production compared with manure as the sole substrate. All digestions were performed in laboratory-scale CSTR reactors (5L) operating with an organic loading late of approximately 2.8g VS/L/day, independent of substrate mixture. The hydraulic retention was 25days and an operating temperature of 37, 44 or 52°C. The co-digestion with steam exploded straw and manure was evaluated with two different mixtures, with different proportion. The results showed stable performance but low methane yields (0.13-0.21NLCH4/kg VS) for both manure alone and in co-digestion with the straw. Straw appeared to give similar yield as manure and steam-explosion treatment of the straw did not increase gas yields. Furthermore, there were only slight differences at the different operating temperatures.
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| 6. |
- Röös, Elin, et al.
(författare)
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Diagnostic, regenerative or fossil-free - exploring stakeholder perceptions of Swedish food system sustainability
- 2023
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Ingår i: Ecological Economics. - : Elsevier B.V.. - 0921-8009 .- 1873-6106. ; 203
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Tidskriftsartikel (refereegranskat)abstract
- In an analysis of food system sustainability challenges and solutions among Swedish food system actors using Q-methodology, five perspectives were identified. One of the main three perspectives placed the highest priority on reduced meat consumption, food waste, and climate impact in agriculture, but downplayed strategies highlighted in the national food strategy and social aspects, and can be interpreted as a diagnostic climate mitigation-oriented perspective that does not reflect current negotiated policy processes or ‘softer’ values of food. In an alternative regenerative perspective, industrialized large-scale farming and lack of internalization of external costs were regarded as the main problems, and diversity, soil health, and organic farming as the main solutions. Proponents of a third perspective regarded phasing out fossil fuels, increased profitability of companies, increased meat production, and self-sufficiency as high priorities. These contrasting views can be a major barrier to transforming the Swedish food system. However, a number of entry points for change (i.e. aspects highly important for some and neutral for others) were identified, including focusing on healthy diets and increased production of fruit and vegetables. Focusing on these can build trust among stakeholders before moving to discussions about the larger and more sensitive systemic changes needed. © 2022 The Authors
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| 7. |
- Mogren, Lars, et al.
(författare)
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Håll bevattningsrören rena
- 2017
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Ingår i: LTV-fakultetens faktablad. - Alnarp : Sveriges Lantbruksuniversitet.
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Annan publikation (populärvet., debatt m.m.)
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| 8. |
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| 9. |
- Cederberg, Christel, 1959, et al.
(författare)
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Trends in greenhouse gas emissions from consumption and production of animal food products - implications for long-term climate targets
- 2013
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 7:2, s. 330-340
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Tidskriftsartikel (refereegranskat)abstract
- To analyse trends in greenhouse (GHG) emissions from production and consumption of animal products in Sweden, life-cycle emissions were calculated for the average production of pork, chicken meat, beef, dairy and eggs in 1990 and 2005. The calculated average emissions were used together with food consumption statistics and literature data on imported products to estimate trends in per capita emissions from animal food consumption. Total life cycle emissions from the Swedish livestock production were around 8.5 Mt carbon dioxide equivalents (CO2e) in 1990 and emissions decreased to 7.3 Mt CO2e in 2005 (14% reduction). Around two-thirds of the emission cut was explained by more efficient production (less GHG emission per product unit) and one third was due to a reduced animal production. The average GHG emissions per product unit until the farm-gate were reduced by 20% for dairy, 15% for pork and 23% for chicken meat, unchanged for eggs and increased by 10% for beef. A larger share of the average beef was produced from suckler cows in cow-calf systems in 2005 due to the decreasing dairy cow herd, which explains the increased emissions for the average beef in 2005. The overall emissions cuts from the livestock sector were a result of several measures taken in farm production, for example increased dairy yield per cow, lowered use of synthetic nitrogen fertilisers in grasslands, reduced losses of ammonia from manure and a switch to biofuels for heating in chicken houses.In contrast to production, total GHG emissions from the Swedish consumption of animal products increased by around 22% between 1990 and 2005. This was explained by strong growth in meat consumption based mainly on imports, where growth in beef consumption especially was responsible for most emission increase over the 15-year period. Swedish GHG emissions caused by consumption of animal products reached around 1.1 tonnes CO2e per capita in 2005.The emission cuts necessary for meeting a global temperature-increase target of 2 degrees might imply a severe constraint on the long-term global consumption of animal food. Due to the relatively limited potential for reducing food-related emissions by higher productivity and technological means, structural changes in food consumption towards less emission intensive food might be required for meeting the 2-degree target.
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| 10. |
- Flysjö, A., et al.
(författare)
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The interaction between milk and beef production and emissions from land use change - Critical considerations in life cycle assessment and carbon footprint studies of milk
- 2012
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 28, s. 134-142
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Tidskriftsartikel (refereegranskat)abstract
- Two most critical factors to address in environmental system analysis of future milk production are 1) the link between milk and beef production, and 2) the competition for land, possibly leading to land use change (LUC) with greenhouse gas (GHG) emissions and loss of biodiversity as important implications. Different methodological approaches concerning these factors, in studies on environmental impacts of dairy production, sometimes lead to contradictory results. Increasing milk yield per cow is often one of the solutions discussed in order to reduce GHG emissions from milk production. However, when also accounting for other systems affected (e.g. beef production) it is not certain that an increase in milk yield per cow leads to a reduction in total GHG emissions per kg milk. In the present study the correlation between carbon footprint (CF) of milk and the amount of milk delivered per cow is investigated for 23 dairy farms (both organic and conventional) in Sweden. Use of a fixed allocation factor of 90% (based on economic value) indicates a reduction in CF with increased milk yield, while no correlation can be noted when system expansion is applied. The average CF for two groups of farms, organic and high yielding conventional, is also calculated. When conducting system expansion the CF is somewhat lower for the organic farms (which have a lower milk yield per cow, but more meat per kg milk), but when a 90% allocation factor is used, the CF is somewhat higher for the organic farms compared to the high yielding conventional farms. In analysis of future strategies for milk production, it is suggested that system expansion should be applied, in order to also account for environmental impacts from affected systems. Thus, scenarios for milk and meat production should be analysed in an integrated approach in order to reduce total emissions from the livestock sector. How to account for emissions from LUC is highly debated and there is no current shared consensus. Different LUC methods result in significantly different results. In this study, four different LUC methods are applied, using data for organic milk production and high yielding conventional milk production systems in Sweden. Depending on which LUC method was applied, the organic system showed about 50% higher or 40% lower CF compared to the conventional high yielding system. Thus, when reporting CF numbers, it is important to report LUC-factors separately and clearly explain the underlying assumptions, since the method of accounting for LUC can drastically change the results. © 2011 Elsevier Ltd. All rights reserved.
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