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Understanding the environmental impacts of wool: A review of Life Cycle Assessment studies
Beverley Henry May 2012
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A review prepared for AWI:IWTO Beverley Henry, Agri Escondo Pty Ltd, May 2012 ii
Understanding the environmental impacts of wool: A review of Life Cycle Assessment
studies A report prepared for
Australian Wool Innovation & International Wool Textile Organisation
October 2011
About the Author:
Beverley Henry
Associate Professor Beverley Henry is a Principal Research Fellow at Queensland University of Technology, and consultant in the areas of agricultural, environment and climate research and analysis. She has roles as an advisor to the Australian Government on Climate Change Research and as Chair of international and national committees developing standards and guidelines for greenhouse gas measurement, carbon footprinting and land degradation and desertification issues.
Disclaimer This study was commissioned by Australian Wool Innovation Limited (AWI). While every effort has been made to ensure the information in this paper is accurate, AWI and the author do not accept any responsibility or liability for errors of fact, omission, interpretation or opinion that may be present, nor for the consequences of any decisions based on this information. Additional relevant information may reside in confidential reports not able to be accessed by the author. Reproduction in whole or in part of this publication is prohibited without the prior written consent of AWI.
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A review prepared for AWI:IWTO Beverley Henry, Agri Escondo Pty Ltd, May 2012 iii
Abstract
Life cycle assessment (LCA) is increasingly being used as a tool to report on the environmental impacts of products, and LCA impact categories are being used individually or in combination to compare the environmental credentials of alternative products. This paper reviews available LCA studies for wool and wool products, and describes the data and methods used as a basis for discussing the extent to which the LCA studies accurately represent the environmental impacts of wool supply chains and provide a framework for comparisons of alternative fibres and textiles.
The nine LCA studies reviewed in this paper were found to vary in their scope, data quality, methods and conclusions. Studies differed in whether they looked at specific wool supply chains or had the objective of producing broad average assessments for a national or global wool industry for comparison of alternative fibres and textiles. This difference in the scope of studies is just one of the factors that has a large impact on data requirements, accuracy of the assessment and finally the capacity of stakeholders to accurately interpret results. There is enormous diversity in wool supply chains around the globe, and this diversity combined with unresolved methodological issues and limitations on data availability and quality, make it extremely difficult to derive a single global representative value for the environmental impact for wool that would allow an accurate and fair comparison with other natural and synthetic fibres.
The critical methodological choices and assumptions in published LCA studies that have affected results are analysed along with how these issues affect the quality of information communicated to consumers and other stakeholders. This information is then synthesised to develop recommendations on future directions and research needs to assist in resolving outstanding methodological questions and addressing limitations in data needed for more accurate environmental impact assessment. For more accurate and fair environmental impact assessment of wool and wool products, key issues are allocation of environmental burden to co-‐products, choice of system boundary and treatment of land use and water use. While development of a common, agreed methodology and credible data for a range of scales of assessment will take time it is critical that research is initiated to enable LCAs to accurately reflect the diversity in production and processing systems. In the short-‐term, a more rigorous analysis of the data that has been assembled for existing LCAs could be used under a well-‐described methodology to provide a more robust impact assessment for wool. In particular, data collated for previous LCA studies of Australian wool products could provide a basis for a robust report and valuable communication on the environmental impact of Australian wool.
Understanding the environmental impacts of wool: A review of LCA studies
A review prepared for AWI:IWTO Beverley Henry, Agri Escondo Pty Ltd, May 2012 iv
Executive Summary
Background: Methods for assessing the environmental footprint of products across their entire life cycle are being implemented using Life Cycle Assessment (LCA) methodology. This tool has been adopted for environmental policy and communication frameworks. LCA methods have been applied to fibre and textile materials to compare the impacts of alternative natural and man-‐made products with the objective of influencing consumer choice and/or to drive reductions in environmental impact. However, although there are standards for conducting life cycle assessment, choices of data and critical methodological assumptions made in conducting a study affect the results and their interpretation.
Wool supply chains: The enormous diversity in wool production between and within countries together with the limited data for key phases of the supply chain, particularly for the on-‐farm phase, make it extremely difficult to present an “average” global representative assessment of the environmental impacts of wool. Identifying differences in efficiencies between supply chains is valuable for identifying opportunities for continuous improvement. However, sheep farming covers a very wide range of geographical and climatic conditions and farm practices and on-‐farm productions is a part of the supply chain that makes a major contribution to key environmental impacts of greenhouse gas emissions, water use and land use. Additionally, there are large differences in technologies and efficiencies for processing and manufacture.
Life Cycle Assessment: Life Cycle Assessment (LCA) is a tool that was developed to quantify the impacts of industrial processes over their full life from raw material inputs to disposal of a manufactured product. It has more recently been applied to agricultural food and fibre products. However, there are significant unresolved issues for accounting for environmental impacts, including water use, land use and net greenhouse gas emissions (including carbon sequestration on-‐farm) for naturally derived products particularly for the on-‐farm phase. The complexity and interpretation difficulties for agricultural LCAs are illustrated by a benchmarking exercise published by the European company MADE-‐BY (2011). In comparative studies, natural textiles, particularly wool, ranked poorly relative to synthetics. This example of basing interpretation of the sustainability of textiles on a broad, simplified life cycle analysis taking ‘worst case’ scenarios to fill missing data highlights many of the limitations of an approach that does not examine the realistic long-‐term environmental impacts of agricultural and industrial production systems.
Summary of LCA Review
• 9 published Life Cycle Assessment (LCA) studies representing a wide range of scope, assumptions, and conclusions were reviewed, covering a large number of producer countries, production environments, supply chains, and products (e.g. apparel , carpet, insulation).
• Production environments in China (19% of global production); Australia (19%), and New Zealand (8%) were analysed. These three countries together produce 46% of the global total. Production is highly skewed to major producer countries with the top nine wool producing countries representing around 63% of global production, with remaining approximately 100 producers each contributing minor quantities.
• Few LCAs have considered the whole-‐of-‐life cycle for wool from on-‐farm through to use and then disposal or recycling, but most analyse only partial life cycle (e.g. cradle-‐to-‐farm gate). This is one factor contributing to the difficulty in comparing results between LCA studies.
Understanding the environmental impacts of wool: A review of LCA studies
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It is critical that the diversity in supply chains be understood and communicated and the value of a single global representative LCA that does not capture this diversity in any comprehensive way is questionable. Some include enteric methane, others do not.
When done well, LCAs for specific supply chains can offer insights into ‘hot spots’ for environmental impacts along the supply chain and provide a tool for monitoring performance over time and promoting continuous improvement. Within the current state of knowledge LCA studies seem more suited to informing businesses on efficiency gains and continuous improvement than for broad national assessments or comparing alternative products such as textiles or carpets.
Methodological and data issues: Improvements in the capacity of LCA studies to provide credible results to inform consumer choices or business decisions require resolution of outstanding issues and development of an agreed methodology. Examples of major outstanding methodological issues include:
• Systems boundary – for a comparison between alternative fibres or textiles, LCAs should use a cradle-‐to-‐grave assessment of the full life cycle. Partial LCAs can be compared only if they include the same processes for the same product type e.g. wool carpet of equal weight from different supply chains. Data availability and quality will also remain a challenge. For a broad LCA, data are most likely to be derived from publications or government statistics and the comprehensiveness and quality will vary regionally.
• Allocation to co-‐products – Sheep production systems have a number of co-‐products within, and separate from, the wool supply chain. Co-‐products such as meat, nutrients from waste and hides are produced in association with wool and allocation of the environmental burden may be made using physical (weight) or economic criteria. Wool sheep may be produced in mixed farming systems with beef cattle and cropping, and allocation of inputs such as fertiliser to different enterprises on the same property requires assumptions on the share of the environmental burden. Economic allocation was the most common choice in existing LCA studies, although this method of allocation is the least preferred of the three alternatives presented in ISO 14044:2006.
• Land use – This indicator is intended to represent the damage to ecosystems associated with human land occupation over a certain period of time but this definition is not a good measure of the impact of grazing. The land area used for extensive grazing of sheep is large but is frequently extensive natural grassland or steppe – land that is not suitable for other production uses. In many regions there is strong evidence of the long-‐term sustainability of good management practices and it is not correct to assume that this land use for sheep farming equates to a negative environmental impact.
• Water use – There is no one standardised method for presenting the impact of water use in LCA. In some countries where water is not a scarce resource, many practitioners do not estimate water use as an impact category. Where it is quantified, the wide range of values for water usage associated with livestock production reflects in large part differences in methodology more than real differences in water consumption.
Conclusions and Recommendations: Despite the outstanding unresolved issues it is likely that LCA will continue to be used as a tool to examine and communicate environmental impact. Recommendations
Understanding the environmental impacts of wool: A review of LCA studies
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are made in this report to reduce the risk of negative outcomes and take opportunities presented by environmental impact assessments:
Recommendation 1: Consolidate existing data and address data gaps
The wool industry is in a sound position to consolidate the findings of LCA studies to provide defensible information on the environmental impact of wool fibres and textiles that is more robust than currently available. For example, further analysis of the comprehensive data and information assembled in previous LCA studies could provide the basis for positive communications on Australian wool supply chains and the stewardship of sheep farming lands and assist industry planning for continuous improvement in environmental performance.
However, the existing LCA studies have highlighted a number of key data gaps. Detailed reanalysis of the datasets from these LCAs is recommended to evaluate the quality of data inputs and whether there are data from more recent research to fill those gaps. Data and metadata are being developed through Government Climate Change programs and industry research for improved simulation modelling, including:
• enteric methane and nitrous oxide emissions on-‐farm;
• water and energy use for farm activities;
• water use and emissions associated with scouring processes; and
• product end use, maintenance and disposal.
The reanalysis could explore whether there are better and more up-‐to-‐date sources appropriate to the goal and scope of a robust LCA as needed for the wool industry to meet emerging needs for environmental accountability. Where gaps remain it is important to identify specific research requirements to address lack of data or deficiencies in quality.
Recommendation 2: Develop globally applicable guidelines for conduct of wool LCAs
While the environmental performance of wool is most appropriately evaluated at a local or regional scale, the global wool industry could agree to develop guidelines for dealing with the critical assumptions in LCA studies relevant to wool through a cooperative effort similar to that undertaken by the dairy industry to develop a consistent LCA approach. Using these guidelines, existing LCAs could form the basis for benchmarking current understanding of environmental impact of wool.
Recommendation 3: Develop a communication strategy for the wool industry
A communication plan based on LCA could provide factual information and realistic perspectives on the impact categories that will remain high for wool, especially greenhouse gas emissions associated with methane from ruminant digestion and land use for grazing. Common key messages would assist to communicate the positive aspects of the environmental performance of production of wool fibre and textiles.
Recommendation 4: Engage with key stakeholders
The potential for misinterpretation of results for LCA studies will remain high into the near future and yet demand for assessments of the environmental performance of products, including natural fibres, looks set to continue. Given this dilemma, it seems very likely that the global wool industry would benefit from active engagement with major environmental assessment and reporting groups such as ‘MADE-‐BY’ and
Understanding the environmental impacts of wool: A review of LCA studies
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DEFRA. Discussions should explore approaches to deal with the complexities and critical assumptions in wool LCAs and opportunities for the industry to cooperate to improve results when publications are shown to present unreliable information would assist in reducing negative public perceptions of wool.
Understanding the environmental impacts of wool: A review of LCA studies
A review prepared for AWI:IWTO Beverley Henry, Agri Escondo Pty Ltd, May 2012 viii
Contents
Page
1 Introduction ........................................................................... 14
1.1 Background and Introduction .................................................................................. 14
1.2 Objectives and Scope of the Review ........................................................................ 14
2 Wool Supply Chains ................................................................ 15
2.1 Global Wool Production Characteristics ................................................................... 15
2.1.1 Sustainability and the global livestock sector ................................................................ 15
2.1.2 Wool Suppliers and Trends in Production ...................................................................... 16
2.1.3 Products and Product Diversity ...................................................................................... 19
2.2 Agricultural Production Characteristics .................................................................... 20
2.2.1 Diversity of wool production systems ............................................................................ 20
2.2.2 Wool processing, manufacture, use and disposal phases of the life cycle ..................... 21
2.2.3 Case study wool production systems ............................................................................. 21
2.2.3.1 Australia ........................................................................................................................... 21
2.2.3.2 New Zealand .................................................................................................................... 22
2.2.3.3 China – wool production and processing ......................................................................... 23
2.3 Use and Disposal in the wool supply chain ............................................................... 26
3 Life Cycle Assessment – Introduction ...................................... 27
3.1 Definition and Description of a LCA study ................................................................ 27
3.1.1 Definition of a Life Cycle Assessment ............................................................................. 27
3.1.2 LCA methodology overview ............................................................................................ 28
3.1.2.1 Goal and scope definition ................................................................................................ 29
3.1.2.2 Life cycle inventory analysis ............................................................................................. 29
3.1.2.3 Life cycle impact assessment ........................................................................................... 30
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3.1.2.4 Interpretation .................................................................................................................. 30
3.2 Standards for LCA .................................................................................................... 30
3.3 Limitations of LCA .................................................................................................... 31
4 LCA Studies for Wool – Overview of methodological issues .... 32
4.1 Goal and Scope ........................................................................................................ 32
4.1.1 System Boundaries ......................................................................................................... 33
4.1.2 Functional Unit ............................................................................................................... 33
4.1.3 Allocation to co-‐products ............................................................................................... 34
4.2 Life Cycle Inventory ................................................................................................. 35
4.2.1 Data sources ................................................................................................................... 35
4.2.2 Assumptions affecting life cycle inventory ..................................................................... 35
4.2.3 Averaging periods and inter-‐annual variability .............................................................. 36
4.3 Impact Categories .................................................................................................... 37
4.3.1 Energy Use ...................................................................................................................... 37
4.3.2 Global warming potential or carbon footprint ............................................................... 37
4.3.3 Water Use ....................................................................................................................... 37
4.3.4 Land use and land use change ........................................................................................ 38
4.3.5 Eutrophication ................................................................................................................ 39
4.3.6 Acidification .................................................................................................................... 39
4.3.7 Depletion of mineral and fossil reserves ........................................................................ 39
4.4 Review of existing Life Cycle Assessment Studies ..................................................... 40
4.4.1 Overview of LCA studies ................................................................................................. 40
4.4.2 Examples of results of LCA studies ................................................................................. 42
4.4.2.1 Results for the impact category of Energy Use ................................................................ 42
4.4.2.2 Results for the impact category of global warming potential (GHG emissions) .............. 43
4.4.2.3 Results for the impact category of Land Use ................................................................... 44
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4.4.2.4 Results for the impact category of Water Use ................................................................. 45
4.4.2.5 Comparative LCA studies ................................................................................................. 45
5 Gaps in Knowledge and Data .................................................. 46
5.1 LCA approaches ....................................................................................................... 46
5.2 Data sources and data quality .................................................................................. 47
5.2.1 Specific supply chain data .............................................................................................. 47
5.2.2 National or global representative LCA studies ............................................................... 48
5.3 Methodology ........................................................................................................... 49
5.3.1 Allocation in wool supply chains .................................................................................... 49
5.3.2 Land use ......................................................................................................................... 50
5.3.3 Water use ....................................................................................................................... 51
5.4 Guidelines for LCA practitioners and communicators ............................................... 52
5.5 Interpretation of LCA Studies ................................................................................... 52
6 Conclusions and Recommendations ....................................... 52
6.1 Recommendations ................................................................................................... 53
References ............................................................................................ 56
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List of key Abbreviations and Definitions
allocation partitioning the input or output flows of a process or a product system between the product system under study and one or more other product systems
AWI – Australian Wool Innovation Limited Australian Wool Innovation (AWI) is the research, development and marketing organisation for the $2.3 billion Australian wool industry. AWI receives statutory levies from Australian wool growers and the federal government to invest in research, development and marketing for the industry, and its objectives include enhancing the profitability, international competitiveness and sustainability of the Australian wool industry. biogenic carbon carbon derived from biomass CF or CFP – Carbon Footprint or Carbon Footprint of a product sum of greenhouse gas emissions and greenhouse gas removals of a product system, expressed in CO2 equivalents CH4 – Methane gas produced during industrial and natural processes including the digestive processes of ruminant animals and which is 25 times as strong a greenhouse gas as carbon dioxide, i.e. it has a Global Warming Potential of 25. CO2 – Carbon Dioxide The most important greenhouse gas produced by human activities, especially burning of fossil fuels. Plants take up carbon dioxide in photosynthesis and store carbon as biomass. CO2-‐e – Carbon dioxide equivalent unit for comparing the radiative forcing of a greenhouse gas to that of carbon dioxide (ISO 14067) functional unit quantified performance of a product system for use as a reference unit GHG – Greenhouse Gas gaseous constituent of the atmosphere, both natural and anthropogenic, that absorbs and emits radiation at specific wavelengths within the spectrum of infrared radiation emitted by the earth's surface, the atmosphere, and clouds (ISO 14067) GWP – Global Warming Potential characterisation factor describing the radiative forcing impact of one mass-‐based unit of a given greenhouse gas relative to an equivalent unit of carbon dioxide over a given period of time (ISO 14067) Impact category
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class representing environmental issues of concern to which life cycle inventory analysis results may be assigned IO-‐LCA – Input-‐Output Life Cycle Assessment In an IO LCA all the sectors of the economy are described, therefore all the contributions to a product system are taken into account. IPCC – Intergovernmental Panel on Climate Change a scientific intergovernmental body established in 1988 within the United Nations to provide scientific assessments of current scientific, technical and socio-‐economic information about the risk of anthropogenic climate change. IWTO – The International Wool Textile Organisation established in 1928 as an arbitration body for the international trade of wool and wool products LUC – Land use change Direct land use change is the change in human use or management of land at the location of the production, use or disposal of raw materials, intermediate and final products or wastes in the product system Indirect land use change is the change in the use or management of land which is a consequence of direct land use change elsewhere Life Cycle consecutive and interlinked stages of a product system, from raw material acquisition or generation from natural resources to final disposal [ISO 14044:2006] LCA – Life Cycle Assessment compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle [ISO 14044:2006] LCI – Life cycle Inventory compilation and quantification of inputs and outputs for a product throughout its life cycle N2O – Nitrous Oxide A strong greenhouse gas with a global warming potential of 298 times that of carbon dioxide, which is released to the atmosphere as a result of nitrogenous fertiliser applications or from animal waste (dung and urine). Offset mechanism for compensating for all or part of the global warming impact (commonly referred to as the carbon footprint) of a product through the prevention of the release of, reduction in, or removal of, an amount of greenhouse gas emissions in a process outside the boundary of the product system Scouring the treatment of textile materials in aqueous or other media in order to remove natural fats, waxes, proteins and other constituents, as well as dirt, oil and other impurities. VW – Virtual Water Virtual water (also known as embedded water) refers, in the context of trade, to the water used in the production of a good or service.
Understanding the environmental impacts of wool: A review of LCA studies
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WF – water footprint life cycle impact category indicator result(s) that assess(es) the contribution of the system under study to water stress [DRAFT ISO CD14046:2011] Water footprint terms:
Blue water -‐ Fresh surface and groundwater, i.e. the water in freshwater lakes, rivers and aquifers
Green water -‐ The precipitation on land that does not run off or recharge the groundwater but is stored in the soil or temporarily stays on top of the soil or vegetation. (This part of precipitation eventually evaporates or is transpired through plants, but green water is potentially productive for plant growth
Grey water is an indicator of freshwater pollution associated with the production of a product, calculated as the volume of freshwater that is required to assimilate the load of pollutants based on existing ambient water quality
water stress situation where stress on the environment or humans occurs related to the water impact, either because of demand on it or when poor water quality restricts its use [DRAFT ISO CD14046:2011] water use any use of water by agriculture, industry, energy production and households wool top the continuous, untwisted, ribbon of wool (‘silver’) produced from the combing machine, after the fleece has been scoured and carded
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1 Introduction
1.1 Background and Introduction
Life Cycle Assessment (LCA)1 has become a widely used tool for providing information on the environmental impact of products often with the intention of influencing consumer choice between alternative goods and services. LCA was developed to consider the entire life cycle of a product and therefore its cumulative impact from ‘cradle to grave’. Other frequently stated objectives of LCA are to achieve improvements in environmental performance or to improve efficiency of production by identifying points in the life cycle for action.
LCA arose out of the industrial sector and has been a useful tool for manufactured products. However, while the objectives are also appropriate for agricultural commodities, there are significant difficulties in applying the same tool to complex and dynamic natural, biological systems that are managed for food and fibre production. Efforts are continuing in many national and international organisations and research bodies to resolve outstanding issues to facilitate use of Life Cycle Assessment for accurately and fairly reflecting the environmental impacts of agricultural products. Moreover, resolution is essential for valid comparisons between alternative natural commodities and between natural and man-‐made products, e.g. comparison of wool and synthetic fibres.
1.2 Objectives and Scope of the Review
The value of LCA in environmental impact assessment and in supporting more sustainable agricultural production depends on the quality of data and consistency, credibility and appropriateness of methodologies. This review evaluates available wool LCAs, to assess and document the methodologies and data quality used so as to provide an understanding of the validity of current comparative analyses of the environmental impacts of fibres and textiles. The review also focuses on the potential for future improvements in understanding of the environmental impact across wool supply chains and the potential to use LCA studies to support and document ongoing advances in managing production for continuous improvement in efficiency and sustainability. Unfortunately the level of detail included in past reporting of LCA studies is often insufficient to determine whether the LCA is scientifically robust or whether comparisons of alternative products are valid and fair.
An objective of this review paper is, therefore, to provide information to support more accurate communication of the environmental footprint of wool production, fibres and textiles relative to alternative products. There is incredible diversity of wool production environments, supply chains, and end product markets around the globe and hence there is a need to understand the prospect of producing a single ‘representative’ LCA which would adequately reflect this diversity to meet a range of reporting, product differentiation and marketing and other stakeholder communication needs.
The paper examines:
1 The term Life Cycle Analysis was formerly commonly used but has more recently been replaced by terms to better represent the two processes involved: Life Cycle Inventory (LCI) and Life Cycle Assessment (LCA).
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• the scope of existing LCAs, in a supply chain sense, and the extent to which they represent the existing wool supply chain; and
• the critical assumptions affecting the conclusions across the existing LCAs, and the extent to which these are realistic or limiting.
Finally, the analysis and identification of gaps in knowledge and data for wool LCA, lead to a series of recommendations relating to (1) the value of consolidating existing data to inform the need for research to enable new wool LCAs to be more accurate through improved methodology, data and systems understanding, (2) the value of developing globally consistent guidelines for wool LCA studies; (3)communication strategies using more accurate and fair environmental impact assessment from completed wool LCA studies, and (4) engagement opportunities with key stakeholders. These recommendations have the objective of supporting an industry response to the increasing requirements for agricultural products to demonstrate sustainability and environmental stewardship.
2 Wool Supply Chains
2.1 Global Wool Production Characteristics
2.1.1 Sustainability and the global livestock sector
Growing populations, rising income and urbanization have resulted in livestock being one of the fastest growing sub-‐sectors of agriculture. Growth in emerging economies has been particularly marked and is associated with a widespread transformation of the livestock sector (FAO, 2011) and within this sector, ruminant animals have attracted widespread attention. Concerns have focussed on climate change issues and greenhouse gas emissions but have also been raised about the sustainability of food systems, public health protection and the urgency of poverty reduction through agricultural development. These concerns will continue to receive attention and have the potential to expand with predictions that demands will result in the world’s livestock production doubling by 2050 to help feed and clothe a population forecast to exceed 9.3 billion by that date.
The outlook from the FAO (2011) and others highlights the significant contribution that the livestock sector can make to meeting society’s environmental, social, economic and health objectives. Technological change to support ongoing increases in resource use efficiency is possible now (e.g. Swan 2010) and can continue to accelerate improvements in sustainability. However, policy changes, adjustments in the regulatory frameworks, and supporting investments are also necessary. In some instances changes are occurring but accurate and unbiased information is critical to enable appropriate directions for progress to be agreed amongst stakeholders with different and competing agendas and consumers. Some of these issues are outlined below.
Livestock are the world’s largest land users with grazing land and crop land used for feed grain production covering 80 percent of agriculturally used land (FAO 2011). It is important however, to understand the extent to which livestock production competes with other agricultural and non-‐agricultural land uses and the areas where it forms a complementary activity e.g. in mixed farming systems. Importantly, much of the land used for grazing ruminant livestock is in arid and semi-‐arid
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regions. This land is not arable and not suitable for other food or fibre production and the rapid sector expansion can be compatible with broader objectives for agricultural development and human occupation. Where competition for land is growing, costs of animal feed, water and energy are increasing. One third of the global cereal harvest is used as feed grain, and hence the livestock sector is also affected by grain price trends. Because of the growing price linkages between grain and energy commodities, increasingly volatile grain and energy prices may disrupt animal agriculture and reduce profitability in those regions relying on feed grains. A global livestock sector that provides a safe and plentiful source of food and fibre for growing urban populations, a contribution to economic growth and sustained wellbeing of livestock producers, needs the preservation and efficient use of natural resources. Therefore, industries such as the wool industry take seriously their responsibilities and their role in environmental sustainability not only on-‐farm but across the full supply chain. However, meeting economic and environmental objectives across the diversity of production systems will require sustained and substantially increased investment in research, development and extension, including in developing countries.
2.1.2 Wool Suppliers and Trends in Production
There has been a continuing and accelerating increase in global fibre production (Turley et al. 2009) to meet the demand of a growing population and increased fibre consumption per capita (Oerlikon 2008). The market share for wool has, however, steadily declined, falling from 9% in 1977 to 6.5% in 2007.
Global production of clean wool (greasy wool after processing and scouring) peaked in 1991 at 2.01 million tonnes and has since declined by almost 50% to 1.06 million tonnes in 2010 (Figures 1 and 3). Wool production in Australia is now at the lowest level of production since the mid-‐1920s. Australia had dominated production until 2010, the latest year for which production data are available, but in that year were overtaken by China. Each contributed approximately 19% of global greasy wool supply in 2010 (FAO, Figure 1). New Zealand is also a significant wool producing nations with 8% of global production. Together these three nations represent approximately 46% of global production with the next six biggest suppliers providing an additional 17% (Table 1).
Figure 1. Greasy wool production (tonnes per year) for example significant wool producing countries and global total production. (FAOSTAT http://www.fao.org/corp/statistics/ Accessed April 2012).
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Amongst the most significant wool producing nations, China is the only country where wool production has increased (Figure 2). Australia, China, New Zealand and the former USSR dominate the production of clean wool (Figure 3). Production amongst the remaining approximately 100 nations reporting greasy wool production is highly fragmented but represents together about 37% of total production. The smallest approximately 100 suppliers represent around 300,000 tonnes per year (Figure 3), equivalent to each producing approximately 1% of Australia’s annual production.
Figure 2. World greasy wool production shares 1980-‐2009, showing shares for top 8 producers in 2009, and aggregate share of remaining 103 producers. (Data source: Dr Paul Swan, AWI. Pers. Comm.)
Figure 3. World clean wool production 1980-‐2009, showing top 8 producers (in 2009), and aggregate of remaining 103 producers. (Data Source: Dr Paul Swan, AWI. Pers. Comm.)
0%
5%
10%
15%
20%
25%
30%
35%
40%
Greasy W
ool Produ
ction (%
World to
tal)
Australia China New Zealand
Former USSR Argentina India
Uruguay South Africa Remaining 103 suppliers
0
400
800
1,200
1,600
2,000
Woo
l Produ
ction ('0
00 clean tonn
es)
Australia China New Zealand Former USSR
Argentina India Uruguay South Africa
Remaining 103 suppliers World Total
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Table 1 Production of greasy wool in the 50 leading nations reported in FAOSTAT. Data are for Year 2010.
Rank Country / Global Production (tonnes) Producing animals (hd)
World + (Total) 2,043,434 336,643,762
1 China 386,768
2 Australia 382,300 67,700,000
3 New Zealand 165,800 26,737,100
4 United Kingdom 67,000
5 Iran (Is lamic Republ ic of) 60,000 66,175,500
6 Morocco 55,300
7 Sudan 55,000
8 Argentina 54,000 10,616,300
9 Russ ian Federation 53,280
10 India 43,000
11 Pakis tan 42,000
12 South Africa 41,091
13 Syrian Arab Republ ic 38,100 24,508,000
14 Turkmenistan 38,000
15 Kazakhstan 37,600
16 Uruguay 34,700 8,049,900
17 Turkey 29,700 18,667,400
18 Spain 28,000 12,234,100
19 Uzbekistan 26,510
20 Algeria 25,900
21 Indonesia 23,796 7,931,900
22 Mongolia 22,300
23 Romania 17,600
24 Iraq 17,200
25 Azerbaijan 15,626
26 Afghanis tan 14,900 13,786,300
27 Ethiopia 14,400
28 Ireland 14,000
29 United States of America 13,770 4,102,600
30 Germany 12,800
31 Saudi Arabia 12,200 10,041,800
32 Egypt 12,000
33 Kyrgyzstan 10,900
34 Tunisia 10,400
35 Brazi l 9,700 14,483,900
36 Libya 9,400 7,686,900
37 Italy 8,939
38 Peru 8,700 5,043,900
39 Chi le 7,808 3,070,900
40 Yemen 7,693 9,206,000
41 Greece 7,600
42 Portugal 7,200
43 Bulgaria 7,000
44 Bolivia (Plurinational State of) 6,641 6,641,100
45 United Republ ic of Tanzania 6,600
46 Tajikistan 5,771
47 France 5,200
48 Mexico 4,683 6,784,100
49 Norway 4,607 1,931,200
50 Hungary 4,300
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2.1.3 Products and Product Diversity
The global clean wool production can be presented in categories that reflect suitability for use (Table 2). Wool that has a mean fibre diameter exceeding 24.5 µm is generally considered too coarse for apparel (excluding some traditional knitwear). The International Wool Textile Organisation (IWTO) estimated that approximately 50% (600,000 tonnes) of the clean wool produced in 2006 was used in the production of apparel (Oerlikon 2008).
Table 2 indicates that the total amount of production (tonnes per year) was relatively stable from 2003 to 2006, but more recently has shown a continuation of the decline since 1990 (Figure 3). Swan (2010) proposed that since there are environmental and economic constraints affecting annual farm production of wool fibre globally, the critical driver of income to the global enterprise is increased retail value per retailed kilogram. Australian apparel wool is estimated to account for 70% of global consumer purchases of wool apparel, and sells at an average of around US$230 per retailed kilogram (Swan 2010).
Table 2. Estimates of global production (tonnes) of various categories of clean wool (Swan 2010).
Almost 96% of the Australian clip is likely to be used for apparel production, assuming a proportion of hand knits are worn as apparel (Table 3)
Table 3. Percentage allocation of the Australian wool clip to apparel end use categories (knits, men’s and women’s wovens and other apparel products) and to non-‐apparel end uses (carpet and hand knit yarns) (Swan 2010, based on Woolmark 2007 statistics).
Wool price is affected by seasonal conditions as well as demand from large consumer nations such as China. The high inter-‐annual climate variability in Australia makes wool production particularly vulnerable to the impacts of climatic conditions, particularly extended drought of the severity of that experienced over much of the pastoral zone from 2002 until around 2009.
Band 2003 2004 2005 2006Total clean wool production (t) All 1,231,429 1,221,005 1,214,784 1,229,771 'Fine' wool production (t) <24.6µm 476,779 469,696 467,377 468,796 'Medium' Wool production (t) 24.6-‐32.5µm 265,599 260,453 260,425 262,735 'Coarse' Wool Production (t) >32.5µm 489,051 490,856 486,982 498,240
Diameter band (µm) Apparel Non-‐apparel % Allocation< = 19.5 30 0 3019.6 -‐ 22.9 47.1 0 4723.0 -‐ 25.9 13.9 1.1 1526+ 4.8 3.3 8Total 95.8 4.4 100
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2.2 Agricultural Production Characteristics
2.2.1 Diversity of wool production systems
Sheep farming for wool production as either a primary product or a co-‐product with sheep meat is conducted in over a hundred countries and on a wide range of scales, geographical and climatic conditions and farm practices. This diversity is illustrated by the geographical, economic and cultural spread across the top 10 wool producing countries of 2010 (Table 4).
Table 4. Summary statistics for world production of greasy wool in 2010 for the top 10 producing countries. (FAOSTAT http://www.fao.org/corp/statistics/ Accessed April 2012).
The type of sheep and the products produced differ between countries. China is now the largest producer of wool, a position held by Australia until 2009. Australia has predominantly Merino sheep, producing fine wool for apparel manufacture. New Zealand is the largest producer of crossbred wool with breeds such as Lincoln, Romney, Tukidale, Drysdale and Elliotdale producing coarser fibres, usually used for making carpets. In the United States, Texas, New Mexico and Colorado have large commercial sheep flocks, and their mainstay is the Rambouillet (or French Merino). There is also a thriving home-‐flock contingent of small-‐scale farmers who raise ‘hobby’ flocks of specialty sheep for the hand spinning market. These small-‐scale farmers offer a wide selection of fleece.
The environmental impacts of sheep farming depend on the intensity of the system and on the climate. Extensive grazing of natural pastures in climates where ‘housing’ is not required in winter months is a low input, low impact system relative to production requiring grain or imported feed and heating. However, common across ruminant animal agriculture is the enteric methane production associated with digestion, and this biological process has attracted attention in the climate change debate as a contributor to greenhouse gas emissions. The case studies below (Section 2.2.3) do not cover the full extent of diversity in wool production in developing and developed countries, but provide examples of the range of production systems in selected countries.
Country Production (metric
tonnes of greasy wool)World + (Total) 2,043,434China 386,768Australia 382,300New Zealand 165,800United Kingdom 67,000Iran (Islamic Republic of) 60,000Morocco 55,300Sudan 55,000Argentina 54,000Russian Federation 53,280India 43,000
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2.2.2 Wool processing, manufacture, use and disposal phases of the life cycle
Post farm-‐gate processing of wool (Figure 4) and textile manufacture stages depend on the type of product and on the country circumstances. The environmental impact, particularly energy use, greenhouse gas emissions and water use, vary widely across these steps. Impacts associated with use and end-‐of-‐life phases in a full life cycle assessment are difficult to quantify because of the dearth of reliable data on consumer practices during the use phase, the degree of recycling and re-‐use and the type of disposal. Washing and drying for textile maintenance are responsible for a significant share of the life cycle environmental impact due to energy (electricity) consumption. The number of years assumed for the life of a product, such as a garment or carpet, is an important but highly uncertain determinant of the estimated impact as the production burden is diluted over longer lasting products.
Figure 4. Typical steps and procedures in the chain of production of wool fibres.
2.2.3 Case studies of wool production systems
2.2.3.1 Australia
There are an estimated 39,000 wool producing farms in Australia (Barrett et al. 2003). The majority (around 70%) are mixed farming systems with the remaining approximately 30% deriving the majority of farm income from wool and sheep. In the mixed farms most of the income is generally from grain crops or beef cattle. In Australia, large specialist and mixed enterprises provide the bulk of national wool production, with the smaller properties that number more than 60% of wool producing properties producing about 27%.
Sheep producing regions in Australia are characterised by annual rainfall (Figure 5, Table 5). The high rainfall zone with average rainfall exceeding 600 mm per year was estimated to carry 33% of the national flock, the sheep-‐wheat zone (300-‐600 mm rain per year on average) accounted for approximately 55% of the national flock, and the pastoral zone (< 300 mm rain per year) which covers the majority of Australia’s land mass has about 12% of the flock (Barrett et al. 2003). Low rainfall and poor soils make the pastoral zone unsuitable for crop production and sheep and wool production is a major agricultural activity in the pastoral zone below approximately 22o latitude. Beef cattle production predominates in tropical regions of the pastoral zone.
The profitability of wool production in Australia is dependent on efficient production of high quality product. In the pastoral zone, this means sustainable grazing of native grasses and shrubs in a highly variable climate.
Animal rearing and shearing
Scouring and top making
Woollen or worsted spinning , weaving
or knitted
Scouring, standard (metal complex)
acid dyeing
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Figure 5. The distribution of wool production in Australia (A) relative to rainfall zones and (B) showing sheep density for statistical divisions (Barrett et al. 2003; data from ANRA 2001) http://www.anra.gov.au/topics/agriculture/sheep-‐wool/index.html)
Table 5. A summary of the distribution of sheep and wool land use on a zonal basis (data from data from ANRA 2001, http://www.anra.gov.au/topics/agriculture/sheep-‐wool/index.html)
Almost 96% of the Australian wool clip is likely to be used for apparel purposes (Table 3) with men’s and women’s woven apparel making up about 60% of production (Table 6). Approximately 32% of Australia’s wool clip is used for domestic consumption. China is the largest export destination.
Table 6. Percentage allocation of the Australian wool clip to various end use categories and fibre diameter bands (Swan 2010, sourced from Woolmark 2007).
2.2.3.2 New Zealand
New Zealand is the world’s largest producer and exporter of crossbred wool. This wool is used for a wide variety of end-‐uses, in particular carpets, interior textiles, and bedding and apparel products.
Region Area (ha)% of Australian sheep area
High rainfall zone 4,690,982 5.5
Wheat/Sheep zone 11,957,240 13.9
Pastoral zone 69,045,822 80.6
Total 85,694,044 100
KnitsMens wovens
Womens wovens
Others inclu. non-‐wovens Carpet
Hand knit yarns Total
< = 19.5 6.0 16.5 6.0 1.5 0 0 30.019.6 -‐ 22.9 16.0 16.5 10.8 3.8 0 0 47.123.0 -‐ 25.9 5.3 3.3 3.8 1.5 0 1.1 15.026+ 1.2 1.2 1.2 1.2 1.9 1.4 8.1Total 28.5 37.5 21.8 8.0 1.9 2.5 100
Apparel Non-‐apparelDiameter band (µm)
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Some fine Merino wool is produced and used in apparel from active outdoor wear to designer fashion.
In 2010, New Zealand was the world’s third largest producer of wool behind China and Australia with production of 165,800 tonnes (Table 4). The wool clip had an export value of NZ$547 million and a total export volume of 133,000 tonnes. In 2009, 44% of the export volume went to China, 8.8% to the United Kingdom and 8.7% to Italy. New Zealand exported NZ$70 million worth of carpet in 2009, 93% of which went to Australia. Wool export prices increased from August 2010 and export revenue for the year ending 30 June 2011 was expected to be NZ$728 million up a further 33% on the previous year (Table 8).
Table 8. New Zealand sheep numbers, clean wool prices and export volumes and values (NZ$), 2008 – 2011.
Wool production in New Zealand has declined since 1990 but is expected to be stable over the next four years (Table 8). Sheep numbers are projected to fall slowly because of pressure from alternative land uses. Merino sheep are farmed in the high country of the South Island of New Zealand, and their numbers are projected to be maintained due to the higher price of fine wool relative to the price of meat. Fine wool accounts for about 8% of total wool volume sold in New Zealand.
2.2.3.3 China – wool production and processing
China is now the world’s largest producer of wool. It is also a major importer. Within China, the wool industry is especially important because of its economic and political significance to ethnic minorities living in the pastoral region. This region is highly vulnerable to overgrazing and land degradation. Wool is the major source of cash income in some districts but because sheep meat is an important part of the food supply for ethnic minorities, the balance between wool and sheep meat in the sheep industry is important, affecting the total quantity of wool produced and, even more so, the type of wool produced (Brown et al. 2011, Watson 1998).
The quality composition of the wool clip determines the types of products into which wool can be processed and thus the extent of competition between domestic wool and imported wool. China is a major wool consumer and also a processor of domestic and imported wool for the Chinese market and export. The clothing and textile industries are an important component of the Chinese economy.
2008 2009 2010 2011Total sheep numbers (mi l l ion) 38.5 34.1 32.4 32.6Average wool sa le price (cents/kg) 378 385 380 503*Export volume (000 tonnes) 146 126 133 133*Export va lue ($ mi l l ion) 610 567 547 728*
* EstimateSource: Beef+ Lamb New Zealand Limited Economic Service, Statistics New Zealand and MAF
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China emerged as a significant purchaser of wool, particularly from Australia, in the mid-‐1980s with the liberalisation of its economy. The interaction between Chinese demand for wool and the reserve price scheme that operated at that time in Australia was complex and together with the volatility of demand from China and some other countries, caused lasting damage to investment decisions in the world wool processing industry (e.g. Watson 1998). It is beyond the scope of this review to examine the economic aspects of this relationship and of the impacts of a buffer or reserve price scheme. Of greater relevance in the context of whether a ‘representative’ wool LCA can add value to understanding environmental impact of wool relative to alternative fibres is the current and emerging contribution of China to wool production, processing and manufacture of products for domestic and export markets. China is now the world’s largest exporter of clothing and second largest exporter of textiles. From 1980 to 1994, textile and clothing exports rose from US$4.4 billion to US$35.5 billion, an increase more than eight-‐fold (Zhong and Yang 1997).
Case studies have supported the theoretical link between growing human population, increased grazing pressure and irreversible land degradation in pastoral areas of China mediated by the behaviour of nomadic herdsmen suffering from declining incomes and widespread poverty and influenced by policies supporting increasing population pressure in these sensitive regions (Watson 1998).
The Chinese wool industry has been characterised according to three broad market segments depending on the nature of the final product and the type of wool processing. At the high value end is ‘genuine fine wool’ (<25 um) used to produce high quality apparel after processing with the worsted system. Although some areas of China’s pastoral region can produce wool of reasonable quality, in general it is not suitable for very fine wool production and China relies heavily on imports of this value product, especially from Australia. A large proportion of the wool grown in China is ‘fine and semi-‐fine wool’ from wool sheep and dual purpose stock. The mills in this segment of the market draw mainly on Chinese raw wool and produce woollens for the domestic market as well as some products for lower value export markets. ‘Coarse wool’ is grown from meat sheep and local sheep and is used to make non-‐apparel products such as blankets, upholstery and carpets (Figure 6, Brown et al. 2011). These products are sold mostly in China with a smaller amount exported. Some wool is imported in this segment to make specialised products such as high quality carpets.
Figure 6. Production of wool (by type) and mutton from the Chinese flock 1981 to 2008 (Brown et al. 2011 with data from China Statistical Bureau (various issues).
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Brown et al. (2011) emphasise the complex interactions within the Chinese wool industry as shown in Figure 7 reproduced from their paper.
Figure 7. Representation of the Chinese wool supply chain (Reproduced from Brown et al. 2011).
Such an internally complex supply chain makes conducting environmental impact studies difficult and time-‐consuming and leads to a high level of uncertainty exacerbated by issues of data availability and quality. The dearth of reliable data and highly dynamic nature of this large and rapidly evolving market have important implications for the concept of a ‘representative’ global wool Life Cycle Assessment (LCA). The uncertainty in a production system and market segment of such significance globally will affect confidence in any resultant LCA and make interpretation problematic. We can start to summarise some features of the environmental aspects of Chinese wool production that would affect development and interpretation of a global LCA, but many of these characteristics are poorly understood outside of China.
In particular, environmental impact assessment of Chinese wool production requires an understanding of the farm systems since most sheep grown for wool in China are grazed in natural grasslands (Brown et al. 2008). Chinese grasslands are heavily stocked and land degradation is recognised as severe in large areas. Central government financial support and policies have begun to be implemented within the last decade to rehabilitate the grasslands through restricting grazing. The efforts to move from increasing stock numbers to increasing livestock value per unit of grazing pressure is very positive but landscape rehabilitation will take a very long time in some regions especially where extremes of climate affect recovery of the feedbase. Moreover, livestock numbers
Production; Export; Trader; Early stage processors; Mills; Garment makers; Export & Retailers
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are tied to communal management and sourcing of food from culled animals in regions such as Inner Mongolia. Further, other social aspects such as livestock as status and wealth banking or insurance interact with environmental goals and these cannot be represented in current LCA methodologies.
Measures introduced since the beginning of the 21st century to address degradation concerns have generally led to an intensification of ruminant livestock production and this has not only had economic impacts but has affected productivity – sometimes negatively as fodder costs can be prohibitive for poor farmers. Wool processing is also an environmental issue since operations such as scouring and fabric dyeing affects effluent and waste water systems especially in larger inland mills. Some were forced into closure or into purchase of expensive treatment technologies, affecting competitiveness (Brown et al. 2008).
Brown et al. (2011) note that wool, unlike other agricultural products in China, is grown mainly in western pastoral areas, i.e. in some of the poorer, rural areas of the country. Wool production is influenced by Western development and poverty alleviation programs, through provision of funds for intervention buying to underpin wool prices and through influencing wool processing so that many of the inland mills originally located in pastoral areas have now closed. These and other challenges facing the wool industry in China need to be considered in developing life cycle environmental impact assessments.
2.3 Use and Disposal in the wool supply chain
The use phase of wool products is responsible for a significant proportion of the life cycle environmental impact because of the electricity (fossil fuels), water and chemicals (detergents) required in washing and drying (Kviseth and Tobiasson 2011, see also Section 4.4.2). For some wool products multiple cleaning cycles may use more energy than manufacturing a garment. Again assumptions must be made about the actions of many individuals to estimate an average environmental impact, and some assumptions, such as the lifetime of a garment or a carpet, can have a significant impact on the life cycle assessment for a product.
The use phase (washing and drying), lifetime, re-‐use or recycling, and disposal all vary between regions and with cultural and economic circumstances. Reliable data for many products are, therefore, difficult to obtain and remain uncertain. There may be considerable scope for efficiency gains and reduction in environmental impacts in the use phase, however, so understanding of this phase for alternative textiles is of value.
In general, the disposal phase adds very little environmental burden to wool products and may be assumed to be a negative score (e.g. Van de Vreede and Sevenster 2010) at least in European incineration or landfill processes where heat and methane, respectively, are effectively recovered. In addition there is a proportion of re-‐use as second hand clothing and of recycling. Nevertheless, data on disposal depend on the actions of many individual households and as such assumptions must be made as to the fate of products.
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3 Life Cycle Assessment – Introduction
3.1 Definition and Description of a LCA study
3.1.1 Definition of a Life Cycle Assessment
A Life Cycle Assessment (LCA) is a method of assessing environmental impact by analysing the complex interaction between a product and the environment for all processes in the supply chain producing the product or service. It was developed for use in manufacturing and processing industries but has more recently been extended to agricultural and other sectors. A full ‘cradle-‐to-‐grave’ LCA covers the entire life cycle of a product, from the extraction and processing of the raw materials needed to make the product to its use, recycling and ultimate disposal. Partial LCA (‘cradle-‐to-‐gate’ or ‘gate-‐to-‐gate’) studies have also been conducted where only part of the supply chain is of interest or is able to be analysed.
Figure 8. Generalised life cycle flow diagram for agricultural products (Henry 2010).
In general, a detailed examination of the life cycle of a product or a process in an LCA provides a source of information to analyse and document environmental impacts in response to increased awareness amongst industry, community and government for improved sustainability of industries. An LCA can, therefore, be used to inform businesses or industries wishing to report, monitor or improve their environmental performance. It can also provide supporting information for governments wishing to legislate or monitor impacts in one or more environmental indicator categories. Further, it may be used by non-‐government organisations and individual consumers when making decisions on product selection or purchasing and forms of LCA are used in eco-‐labelling to influence consumer choices.
A feature of LCA, arising from its integration of all the environmental impacts produced during the entire life cycle of a product or function, is that it can be used to prevent three common forms of problem shifting:
• problem shifting from one stage of the life cycle to another:
• problem shifting from one sort of impact category to another: and
C Footprint - Life Cycle Assessment
Inputs Farm Processing Distribution Use Disposal
Cradle Farm Gate Grave
Environmental Impacts ,e.g.Ø Greenhouse gas emissions
Ø Resource depletion (Land use, Water use)
Ø Energy Use
Ø Eutrophication (Nutrients)
Product (Functional unit)
Processor
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• problem shifting from one location to another.
Single impact assessment, such as a carbon footprint or a water footprint, has become more common in recent times, but a serious limitation is that there is an increased risk of problem shifting to between environmental impact categories and resultant un-‐reported perverse outcomes. Therefore, interpretation of the results and subsequent recommendations must consider the potential for unexpected impacts on indicators that are not the subject of a single impact assessment.
As discussed in Section 4, the most significant environmental impacts for wool production are energy use, climate change, water use, land use, eutrophication and acidification and pollutants (respiratory inorganics).
3.1.2 LCA methodology overview
The applications of the results of an LCA study are defined in the goal and scope of the LCA as illustrated in Figure 9 with some examples of these applications. Some key features of the LCA methodology relevant to applications to agricultural products such as wool are listed below but this list, adapted from ISO 14040 (2006), is not intended to be comprehensive:
• LCA assesses the environmental aspects and impacts of a product system, from raw material acquisition to final disposal, in a way that is consistent with the goal and scope of the study and presents the results relative to the ‘functional unit’ e.g. 1 tonne greasy wool;
• the depth of detail and time frame of an LCA may vary considerably, depending on the goal and scope;
• provisions can be made, depending on the intended application of the LCA, to respect confidentiality and proprietary matters relevant to the product and its life cycle;
• LCA methodology is open to the inclusion of new scientific findings and improvements in data; along with the principle that the methodology allows for flexibility with no single correct method, this makes comparisons of results between studies or across time difficult;
• ISO methodology for LCA includes the provision of specific requirements if results are to be used in comparative assertions for the public;
• LCA addresses potential environmental impacts and does not predict absolute or precise environmental impacts due to:
o the relative expression of potential environmental impacts to a reference unit, o the integration of environmental data over space and time, o the inherent uncertainty in modelling of environmental impacts, and o the fact that some possible environmental impacts are clearly future impacts;
• there is no scientific basis for reducing LCA results to a single overall score or number, since weighting requires value choices.
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Figure 9. Major stages in a general framework for Life Cycle Assessment (LCA) and the generalised applications (Adapted from ISO 14040, 2006). Conducting an LCA is normally an iterative process as indicated by the forward and reverse arrows.
3.1.2.1 Goal and scope definition
The first stage of LCA is defining the goal and scope of the study. The goal must clearly state the reasons for carrying out the study and its intended application and the audience for which the results are intended (ISO 14044:2006). The scope should define methodological issues, the product system and the limitations of the study. Note that for agricultural LCAs the Goal and Scope should also describe the time period and geographical region for the study because these help define relevant agricultural practices (Harris and Narayanaswamy 2009). The scope of the study should include impacts for the whole life of livestock and plants.
The scope includes information on the functional unit, system boundary, data quality, allocation questions, environmental impact categories to be assessed and communication plan. Many of these issues are complex and can result in inconsistencies between studies that invalidate comparisons. They will be discussed in Section 4 of this review with relevance to LCA studies for wool products.
3.1.2.2 Life cycle inventory analysis
Life cycle inventory analysis (LCI) is the second stage of the LCA study. LCI involves the collation and processing of data, and includes all aspects of data retrieval and management. This stage is often the most time-‐consuming part of an LCA study and may represent in excess of 80% of the total effort. Data quality should comply with requirements set out in ISO 14040:2006. Validation and aggregation are important steps in determining the quality of an LCA and system boundaries may be refined as an outcome of the LCI analysis.
For agricultural LCAs, data for on-‐farm production are often a major determinant of the quality of the final assessment. However, LCA models may not represent farm practices at all well and LCA
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practitioners may not understand the fundamental science of the processes that determine dominant resource use and emissions in biological processes and in on-‐farm management. As a result, the boundaries may not be appropriately drawn and the correct data may not be collected, so that impact assessment and interpretation are compromised.
3.1.2.3 Life cycle impact assessment
Life cycle impact assessment (LCIA) uses the results of the LCI phase to evaluate the magnitude and significance of the potential environmental impacts of the product or service being studied. The mandatory steps in the LCIA process are (ISO 14040:2006):
• Selection of impact categories, category indicators and characterisation models; • Classification i.e. assignment of individual LCI results to impact categories; • Characterisation i.e. conversion of LCI results to common units within each impact category
and calculation of category indicator results.
In addition optional elements including normalisation, grouping and weighting may be conducted to assist with interpretation.
3.1.2.4 Interpretation
The interpretation stage enables conclusions and recommendations to be reached in accordance with the defined goal and scope of the LCA study. The interpretation is a systematic process to identify, quantify, check and evaluate the conclusions of the study (ISO 14040:2006). The ISO standard also recommends that if the LCA results are to be disclosed to the public, a critical review be conducted.
3.2 Standards for LCA
Standard methods have been developed for LCA by the International Standards Organisation (ISO), and, at the time of this reporting(2011), are being devised specifically for carbon footprinting and water footprinting. These standards set out the requirements for determining the environmental impact of a product or service, in an attempt to give a consistent approach across businesses and applications.
The standards relevant to LCA are:
ISO Standards
• LCA standards – ISO 14040:2006 Life Cycle Assessment – Principles and Framework – ISO 14044:2006 Life Cycle Assessment – Requirements and Guidelines
• Environmental communication standards – ISO 14020 series: Environmental labels and declarations
• Carbon footprint standards – ISO 14067:DRAFT Environmental Management -‐ Carbon footprint of products — Requirements and guidelines for quantification and communication
• Water footprint standards – ISO 14046:DRAFT Water footprint-‐Requirements and guidelines
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Other Standards or Protocols
• PAS 2050: Specification for the assessment of the life cycle GHG emissions of goods and services (BSI 2011)
• WRI: Product Life Cycle Accounting and Reporting Standard (WRI & WBCSD 2011)
These Standards address somewhat different objectives and, despite efforts towards harmonisation, differences in the treatment of some issues remain. Taking the three major standards for carbon footprinting the different purposes or audiences can be summarised:
• ISO 14067 aims to provide consistency for quantifying, monitoring, reporting and verifying the carbon footprint of products and guidance for communication to internal or external stakeholders.
• PAS 2050 (BSI 2011) was developed for internal assessment of life cycle GHG emissions of products and allow for comparisons, evaluation of alternative products and benchmarking.
• WRI/WBCSD (WRI & WBCSD 2011) support public reporting by businesses of product life cycle GHG emissions to help users (e.g. a facility or company) reduce these emissions. The protocol does not support comparisons or labelling.
3.3 Limitations of LCA
The limitations on interpretation of LCAs relate to both data and methodology. Some of the difficulties in data for either a broad LCA (e.g. national average) or specific supply chain and for methodology are exclusive to agricultural LCAs while others are more general.
The quality of data inputs will have a significant impact on the accuracy of an LCA and gaps in data or differences in allocation or aggregation procedures can, in turn, limit the value of the results. For agricultural LCAs, the on-‐farm phase is normally a significant contribution to some impacts across the entire life cycle but management and practices by individual farmers and site and climate characteristics vary enormously affecting resource use. Unlike many factories or industrial sites which are largely site-‐independent, highly variable farm sites do not fit the LCA methodology well. Hence an LCA for polyester fabrics manufactured in the US and Asia could be compared quite well but wool textiles produced in New Zealand and China can have very different environmental impacts. Site dependency characteristics have been shown to have more influence on LCA results than activity dependent factors (Cowell and Clift 1997).
Data limitations, time and financial constraints limit the ability to undertake full life cycle assessments for agricultural products. Despite many of the studies following the methodologies described in ISO 14040:2006 and ISO 14044:2006, this review highlights the lack of consistency between studies that make comparisons very uncertain or invalid. The complex accounting elements in undertaking a life cycle assessment study serve to highlight the many assumptions necessary. These have the potential to influence the result and the ranking of alternative products in a comparative study.
Aspects of the biological processes that influence the interaction between an agricultural product such as wool and its environment are poorly understood, and this introduces a further uncertainty into life cycle impact assessment. The complex agro-‐ecosystems that underpin agricultural
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production respond to natural as well as anthropogenic factors and attribution of a particular environmental impact to a product is not straightforward.
LCAs do not offer scope for recognition of positive impacts arising from farm management but focus on the negative impacts. For example many farmers plant trees that sequester carbon and may improve water quality by decreasing erosion on the same property where sheep are emitting methane, but the LCA methodology does not allow for offsets. Many farmers also actively promote soil health, biodiversity, control weeds and feral animals and manage animal welfare during droughts. These are also not recognised in the LCA methodology.
When done well, LCAs can offer insights into the environmental impact of processes in a supply chain. A robust LCA also provides a tool for monitoring performance over time and promoting continuous improvement. Within the current state of knowledge LCA studies seem more suited to informing businesses on efficiency gains and continuous improvement than for broad national assessments or comparing alternative products such as textiles.
4 LCA Studies for Wool – Overview of methodological issues
4.1 Goal and Scope
Agricultural LCAs can be grouped according to two distinct goals:
a) comparative studies of products to show differences between countries/regions or to rank alternative products; these studies may be conducted at a national or global commodity scale and typically rely on broad statistics from publications such as national surveys or government reports; and
b) studies to understand a specific supply chain using data collected from a real farm(s) and supply chain(s) aimed at identifying ‘impact hotspots’ in the product life cycle so as to drive improvement in environmental performance and document efficiency gains.
For national or global commodity (e.g. natural and synthetic fibre) LCAs, the objective is to achieve a result that represents a production average. In these studies there are many sensitive assumptions that affect the result and these must be clearly stated for the study to have value. These broad studies are frequently limited by data availability or by an inability to meaningfully define a ‘representative’ supply chain because of the high degree of regional diversity or change over time. For natural fibres such as wool, the on-‐farm phase is complex and dynamic and a broad approach that doesn’t recognise specific practices may result in environmental impacts to be under-‐ or over-‐stated.
Alternatively, a specific supply chain approach, while more accurately reflecting a real situation, is likely to be of limited value on an industry or country basis because it can’t be extrapolated more generally. Specific supply chain data can be very expensive and time-‐consuming to collect, and farm, processing and manufacturing records may be of variable quality. Economic, e.g. markets and trade, or seasonal conditions (such as drought) may severely skew results if a single year is examined.
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4.1.1 System Boundaries
Full ‘cradle-‐to-‐grave’ studies for natural products such as wool are rare, with most studies looking only to farm-‐gate or to processing and manufacture. The consumption and disposal phases are subject to a wide range of individual practices. Assumptions made for these life cycle stages should be well-‐documented in an LCA report to enable the user to understand how representative they are.
The difficulty in comparing LCA results for studies that use different system boundaries was highlighted by Kviseth and Tobiasson (2011) who analysed the benchmark assessment of fibres by ‘MADE-‐BY’. Kviseth and Tobiasson (2011) demonstrated the differences in system boundary used in studies (Figure 10) and the way that a partial LCA could put additional weight on the impacts for one part of the supply chain such as the on-‐farm phase, thus influencing the ranking of products in a comparative study.
Figure 10. Different systems boundaries used in different assessments and tools influence the results of comparative studies. (Reproduced from Kviseth and Tobiasson, 2011).
Many agricultural studies are partial LCAs with the system boundary at the farm gate (e.g. Eady et al. 2010). Even in this simplified approach there can be many variations on processes included within the systems boundary and considerable challenges in obtaining the data required for the LCA study.
4.1.2 Functional Unit
The functional unit defines and quantifies the identified functions and is to be consistent with the goal and scope of the study. It must be measureable so as to provide a reference for normalising input and output data in a mathematical sense. The functional unit also allows comparison of data between similar stages and provides the reference for allocation of environmental impacts of co-‐products. In reality the functional unit is frequently linked to the system boundary with on-‐farm impacts often expressed per kg greasy wool and full life cycle impacts expressed per kg men’s suit fabric or per m2 carpet.
The capacity to evaluate studies or to compare between products may be compromised because the functional unit is poorly defined. For example 1 kg wool should be described as either greasy or
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clean wool, or 1 m2 carpet should be defined as either including or excluding backing material and may be quantified by weight.
4.1.3 Allocation to co-‐products
Most agricultural production systems, and many industries, produce both primary and secondary products. Allocation is the process by which environmental burdens are divided between these primary and co-‐products within the LCA. It is a step within the LCA that can have a large bearing on the result, and yet it is often poorly described in published studies. Moreover, it depends on data that are frequently incomplete and variable in time and between individual supply chains and these variables introduce further uncertainty.
Sheep production systems have a number of co-‐products within, and parallel to, the wool supply chain. Co-‐products that are produced in association with the primary product (wool) being studied in the LCA are generally, but not always, of lower value and possibly lower quantity. Examples of the challenges in allocation to co-‐products for sheep producing wool include:
• Sheep meat – numbers of the flock for slaughter may vary with season and prices.
• Manure – manure can be considered as a co-‐product of production that may be used as a fertiliser replacement.
• Slaughter co-‐products – i.e. hides, offal, meat/blood meal etc generally have lower value but can make up more of the total mass of products.
Not only do sheep farms frequently produce meat, wool and secondary slaughter products, but many have mixed production systems so that inputs are divided between agricultural products such as beef and crops on the same property (See e.g. Eady et al. 2010). As an example of the complexity of mixed farming systems in higher rainfall regions of Australia, a property may produce fine Merino wool as the primary product with the following production systems also operating:
• Sale of surplus sheep such as young wethers at 12 months of age provides additional farm income from the sheep flock;
• The same property may also operate a store cattle enterprise, e.g., by purchasing weaners (9 months of age) and growing on for a further 12 months, before selling them for slaughter as grass-‐fed beef or sold to a feedlot for finishing on grain.
• If the land and climatic conditions (particularly rainfall) are suitable, some cropping is often carried out either to produce additional fodder that is consumed on-‐farm or to grow grain for human consumption. The cropping rotation is often incorporated into the overall pasture development program for the property, such that improved pastures are sown after the cropping phase. Nitrogen fertilizer is used for cropping but fertilizer application on pasture is usually limited to superphosphate, and legumes such as white clover may be included in the pasture phase to maintain nitrogen.
• Many properties have a proportion of remnant native pasture as well as introduced species and these provide ecosystem services and possible greenhouse gas offset credits.
All of these co-‐products should be considered in assessing the environmental impact of wool production on the property. Co-‐products in LCA are handled in a number of ways, with ISO 14044:2006 recommending that allocation be carried out according to the following guidelines:
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• wherever possible, allocation should be avoided by correct delineation of the system boundary or system expansion
• where allocation is not avoidable, inputs and outputs should be partitioned between different functions or products in a way that reflects the underlying biophysical relationships between them
• if the latter is not possible, allocation should be carried out based on other existing relationships (e.g. in proportion to the economic value of products).
Depending on the method used, considerable differences in the final result may be observed. Most wool LCAs conducted to date have used economic allocation which tends to give a lower impact assessment than physical allocation (see, for example Figure 12).
4.2 Life Cycle Inventory
4.2.1 Data sources
Livestock production and agronomic practices vary widely between and within countries, depending on geographical features, climate, economy and tradition. There are serious limitations on the availability of reliable data that is sufficiently disaggregated to enable a realistic representation of production across many (perhaps several tens of thousands) individual farms in developed countries. For developing countries the situation is compounded and there is commonly a dearth of understanding of practices and how they vary spatially and from year to year. More than 100 countries report wool production (FAOSTATS, see Table 1) highlighting the diversity of the industry globally.
For the processing phase of the wool supply chain, there are limitations in the availability of data on the quantity and combinations of chemicals used and their potential ecotoxicological impacts (Turley et al. 2009). The use and disposal or recycling stages of the supply chain involve the un-‐documented actions of many individuals and estimation of an average environmental impact relies on highly uncertain assumptions. Some, such as the lifetime of a garment or a carpet, maintenance regime, whether it is recycled and the method of disposal, can have a significant impact on the estimated environmental impact of the product.
4.2.2 Assumptions affecting life cycle inventory
Critical assumptions in the LCA affect the data requirements and the inventory sources. For agricultural LCAs, allocation is particularly challenging for inventory as well as methodological reasons. While economic allocation is not the recommended approach in ISO 14044:2006, it is a method that has been used in several LCA studies. Where sheep provide both meat and wool, the two main products each have significant economic value and are subject to market and seasonal variations. Data sources and timing for markets will therefore affect the allocation.
A further inventory challenge arises for the ‘global warming’ impact of agricultural products, especially for ruminant livestock. Ruminant animals produce methane during the digestive process and enteric emissions represent the greatest proportion of greenhouse gas emissions (global warming potential) on-‐farm, and potentially across the supply chain depending on the assumption
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made regarding use and disposal phases. However, calculations are often based on broad default values from national or international inventory methodologies, such as those published by the IPCC (IPCC 2006). On the other hand, some LCA studies do not account for livestock enteric methane emissions and comparisons of the relative climate change impact of different fibres with and without inclusion of this source of emissions produce very different rankings. Where livestock emissions are included, the treatment of the entire herd, including breeding stock, as well as the specific animals contributing the product should be included in the impact assessment. For example, Biswas et al. (2010) reported a study for a southern Australian mixed farming system that focussed on lambs and excluded the breeding stock, making it impossible to compare with full farm systems analyses.
Other impact categories inconsistently included in agricultural LCAs are water use, land use and land use change which make interpretation of environmental impact assessments challenging. These are discussed in more detail in Section 3. The variation in approaches and absence of data reflects, in part, the origin of LCA studies in the industrial and manufacturing industries where land use and water use are not generally of concern. Debate about the sustainability of biofuel production in recent years has highlighted the need for reliable inventory data to help standardise treatment of these impact categories.
4.2.3 Averaging periods and inter-‐annual variability
Year to year farm management practices and decisions on enterprise mix and outputs depend on, amongst other factors, seasonal quality. Rainfall amounts in broadacre regions and weather variables such as frost or hail that affect crop and pasture quantity and quality are examples of climate variability that affect production and impacts. In addition, economic drivers such as cash flow, markets and prices may be linked to seasonal quality. Social factors such as tradition, farmer preference and personal circumstances are also important determinants of the variability in practices and in record keeping, and hence data availability and quality. For example, the greenhouse gas emissions (global warming impact of products) will vary markedly with the number of stock grazed on the property and the rate of application of nitrogen fertilizer. For livestock production systems, fertilizer use is largely driven by the area of crop planted each year for stock feed.
Data requirements increase as a consequence of normal year to year variation in stock numbers, species mix and cropping area.
Some studies have sought to estimate how many years’ data are needed for an averaging period to enable valid interpretation of the quantified impact results from LCA studies. ISO 14067 (December 2011 draft) defines the time boundary for data as the time period for which the quantified figure for a product carbon footprint is representative, and states that data must be collected over a period of time sufficient to establish the average greenhouse gas emissions and removals associated with the life cycle of the product. This time period is to be specified and justified in the LCA report. In reality periods of 1 to 5 years have been used to estimate average impact, but the period will often be limited by the availability of stable data. In general two years is considered a minimum for agricultural cropping LCA studies (Harris and Narayanaswamy 2009) and preferably 3 to 5 years to be consistent with the IPCC and for livestock production (e.g. Eady and Ridoutt 2009).
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4.3 Impact Categories
4.3.1 Energy Use
LCA methodologies most commonly calculate the ‘cumulative energy demand’ of a product. This is a measure of the total amount of energy consumed in the life cycle of a product, including the energy utilised and energy incorporated into products. Biomass and other renewable energy inputs as well as fossil energy are included. This impact category in LCAs is an indicator of efficiency as it represents the total energy inputs per unit of production rather than the environmental damage from energy use.
4.3.2 Global warming potential or carbon footprint
This impact category is an estimate of the contribution of the functional unit to global warming potential (GWP) in units of mass (typically kg) of CO2-‐e per unit of product . The unit may be m2 (e.g. carpet) or kg (e.g. wool). The major contribution to the GWP of wool products is generally enteric methane. Methane, which is produced in the digestive process of ruminant animals is a strong greenhouse gas, having a global warming potential of 25, i.e. a unit mass of methane causes 25 times the radiative forcing as the same mass of carbon dioxide. Emissions of methane from waste (dung and urine) and nitrous oxide from waste and fertiliser applications are also significant sources of on-‐farm greenhouse gas emissions. Carbon sequestration in vegetation and soils is generally not included in LCA studies. Fossil fuel CO2 emissions from electricity and transport are the main sources of greenhouse gas emissions from the processing and use phases of wool products as well as contributing to on-‐farm emissions.
4.3.3 Water Use
The traditional classification of water use in LCAs was a measure of the gross amount of water extracted from the natural environment as thousands of litres (kL) per functional unit product. This concept is now being challenged by approaches using a more comprehensive accounting for types of water used and inclusion of consideration of the level of water stress in a region (stress-‐weighted water footprint).
Many practitioners, particularly those in Europe where water scarcity is not such a problem as in Australia and in parts of China and Africa, do not routinely estimate water use as an impact category in LCA studies. Where it is estimated, there is currently no agreed and standardised method for presenting the impact of water use in LCA. Approaches currently being used or trialled are:
− Water footprint concepts -‐‘blue’, ‘green’ and ‘grey’ water use
− LCA water indicators or impact categories –stress weighted water footprint
− Water balance/partial balances (i.e. water engineering approaches)
− ‘Extracted’ water use.
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As a result of methodological differences a wide range of values has been reported for water usage for livestock production (See e.g. Wiedemann and McGahan, 2010). For example, values reported for water use to produce 1 kg beef (sometimes inadequately defined as a functional unit, i.e. without clarity on whether ‘beef’ is carcase weight, at retail as bone in or bone out) have ranged from 27L/kg to over 100,000L/kg. The very high values use a water footprint or ‘virtual water’ calculation that includes ‘green water’ or all rainfall in the areas of production. Many practitioners argue that this does not reflect either the impact of livestock production on ‘contestable’ water or the environmental impact of water use in livestock farming (e.g. Ridoutt and Huang 2012).
In the wool supply chain the main contributions to water use are the in-‐use phase (due to the requirements for garment laundry) and the on-‐farm phase. Mills used to produce fabric for garments may also be relatively high users of water. The on-‐farm estimates include water used in production of nitrogenous fertilisers if these are used (generally for fine wool in higher rainfall systems), while sheep in hot and dry pastoral zones have a high intake of drinking water. In some studies (e.g. Russell and Slota, 2011), the volume of urinary water returned to the soil (‘brown’ water) is subtracted from the total water consumed on the basis that urinary water (with nutrients) is retained on the farm and contributes to plant growth. Urinary water is generally included in accounting because nitrous oxides generated from the urine patches are a component of the farm greenhouse gas emissions.
4.3.4 Land use and land use change
The impact category ‘land use’ is intended to represent the damage to ecosystems associated with human land occupation over a certain period of time. There are frequently insufficient data on historic land use and where data do exist there are large uncertainties in attribution of change in land condition to natural (e.g. drought) vs anthropogenic (e.g. over-‐grazing) factors. Moreover, there is a wide variety of land management practices between individual farmers.
In many regions, however, there is evidence of the long-‐term sustainability of good management practices so that while sheep are grazed over large areas in extensive production systems, it is not correct to assume that this land use for sheep farming equates to a negative environmental impact. In many regions pastoralists act as environmental stewards of extensive sparsely populated areas that could otherwise be subject to weed invasions, damage by feral animals and loss of biodiversity through uncontrolled wildfires.
A further issue for interpretation of land use as an impact category is that it is most frequently presented as a single unqualified figure, i.e. all land is assumed equal. In reality demand for good quality, highly productive land for urban expansion, cultivation or infrastructure is much greater than demand for expanses of semi-‐arid or arid rangelands that are non-‐arable and remote from major cities and access to business and transport hubs. Weighting of land use on its potential for alternative use would provide a better indication of the social as well as environmental impact of use for production of food and fibre in LCA studies and a few practitioners are now attempting to develop standardised more informative methodologies for accounting for land use (e.g. Ridoutt et al. in preparation).
Land use change releases greenhouse gases to the atmosphere when forests are cleared for cropping or grazing land uses. The treatment of land use change in life cycle assessment studies
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varies, but when included the GWP impact of land use change can be so high as to completely dominate other sources arising over the entire life cycle of a product. The draft ISO standard for quantification of the carbon footprint of a product (ISO 14067:2011) states that, when significant, the GHG emissions and removals occurring as a result of direct land use change shall be assessed in accordance with the goal and scope of the study using internationally recognized methods such as the IPCC Guidelines for National Greenhouse Gas Inventories (IPCC 2006) and shall be included in the product carbon footprint. While in most developed countries, land development took place many decades previously so that the impacts of land clearing is not significant in LCA studies, for lands more recently converted to agricultural use it may dominate the environmental impact assessment.
Indirect land use change, i.e. the conversion of land in a separate location as a result of production in a region, is generally not included although ISO 14067:2011 (December 2011 draft) states that if a method for accounting for indirect land use change becomes internationally accepted in future then it should be reported in the assessment.
4.3.5 Eutrophication
Eutrophication describes the release of nutrients from production activities resulting in elevated concentrations in waterways, frequently leading to proliferation of some species that exhibit strong growth and reproduction due to nutrient surplus. The outcome is generally a loss of biodiversity as less vigorous species are out-‐competed. Fertiliser and manure in run-‐off from farming activities can increase concentrations of nitrogen and phosphorous causing algal blooms in rivers and estuaries. Eutrophication can lead to hypoxia (oxygen deficiency) or release of toxins making waterways unsafe for human or animal use.
Eutrophication is rarely a problem in extensive sheep farming but in mixed grazing and cropping systems or in intensive high rainfall specialist systems use of fertilisers on pasture or crops and concentration of dung and urine can be subject to leaching or run-‐off problems. Many countries regulate the impacts of farming systems on waterways and impacts are also increasingly managed through recycling of animal waste.
4.3.6 Acidification
Acidification of soils and water can arise from agricultural activities and from use of chemicals and fossil fuels in processing, manufacture and transport of textiles. Emissions of acidifying compounds such as sulphur dioxide, nitrous oxides, ammonia and volatile organic compounds may be transported in the atmosphere or be dissolved in water flows and re-‐deposited in soils, lowering the pH. Acidic substances can affect the health of crops, pasture grasses trees and other plants making them less vigorous and more susceptible to disease. Acid deposition may also negatively affect wildlife relying on rivers and lakes for habitat or drinking water.
4.3.7 Depletion of mineral and fossil reserves
In developing LCAs for comparison of natural and man-‐made goods, the consumption of mineral resources and fossil fuels is sometimes, though not always, included. The impact of depletion of a resource increases in magnitude as reserves becomes scarcer and its availability declines, based on a measure of the marginal increase in extraction costs.
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4.4 Review of existing Life Cycle Assessment Studies
4.4.1 Overview of LCA studies
Tables 9 and 10 provide a summary of 9 published LCAs that have been conducted for wool that are available as public reports or peer-‐reviewed papers. The studies vary not only in their goal and scope (Table 9) but also in their data sources and quality and critical assumptions (Table 10). As a result, comparisons of the results for the environmental impacts of wool from these different studies are not possible. Nevertheless, some studies had as their primary objective, the communication of comparative assertions on alternative natural and/or synthetic fibres or textiles, and these studies are generally based on analysis of published data and broad assumptions.
Table 9. Life cycle stages included in LCA studies reviewed in this paper. Note that in addition, transport contributes to the environmental impact across several stages of the supply chain.
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Table 10. Life cycle stages included in LCA studies reviewed in this paper with a summary of the major LCA methodological characteristics of each study.
The methodological summary of the available wool LCA studies is presented in Table 10, but in some cases there was insufficient detail in the papers as available to confidently determine the methodology and therefore there is some uncertainty that all interpretations of the reports presented in Tables 9 and 10 are correct. Further, differences in results for environmental impact assessment may be due as much to differences in methodology as to real differences in impact. Comparison of impacts for wool apparel and non-‐apparel production must consider the different supply chain features. For example, industrial processes will likely make up a significantly higher component of the total impact in carpet than in textiles. Overall, current LCA comparative studies
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represent an over-‐simplification of the impacts of the diversity of wool production systems and highlight above all else the gaps in knowledge and data for fully understanding the environmental impacts of wool and for analysing the relative impacts of different natural and synthetic fibres and fabrics.
4.4.2 Examples of results of LCA studies
Interpretation of the reported results from LCA studies is complex due to the number of methodological and data factors that can affect the outcomes. Some illustrative examples are included below. While comparative assertions are strongly discouraged unless methodologies are totally consistent , a short discussion is included as Section 4.4.2.5 to highlight the limitations of studies that attempt to make comparisons.
4.4.2.1 Results for the impact category of Energy Use
Barber and Pellow (2006) reported results for the impact category of Energy Use for the on-‐farm phase of production for New Zealand merino wool of 13.42 MJ per kg greasy wool or 22.55 MJ per kg wool fibre. Energy use in intensive farm systems was 21% higher than for extensive farms. Fertiliser and liquid fuels were the highest contributors to total energy use, making up approximately 19% and 20% of the total on-‐farm use, respectively. The total energy use from on-‐farm through to a spinning mill in China was estimated to be 45.73 MJ/kg wool top (Table 11; Barber and Pellow, 2006). The process with the greatest uncertainty in energy use was scouring and since this contributed almost 90% of the total processing use and processing was the single largest energy user in the supply chain there is high uncertainty in the results.
Table 11. Energy use and greenhouse gas emissions (GWP) for 1 tonne merino wool top from New Zealand as reported by Barber and Pellow (2006). Note that the estimated greenhouse gas emissions do not include methane and nitrous oxide (strong greenhouse gases) produced on-‐farm.
The qualitative study by Turley et al. (2009) concluded that energy use for wool production is low relative to alternative synthetic fibres. Estimated values for energy use for producing 1 m2 woollen carpet are highly dependent on the weight of the carpet and interpretation requires careful definition of the functional unit. In a study from the Netherlands, Potting and Blok (1995) estimated 157 MJ energy was required to produce 1 m2 carpet with a weight of 2600g (Table 12).
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Table 12. Summary of results for environmental impacts of 1 m2carpet produced in the Netherlands as reported by Potting and Blok (1995).
4.4.2.2 Results for the impact category of global warming potential (GHG emissions)
Current focus on climate change and mitigation of greenhouse gas emissions by governments, environmental groups and others around the globe has led to the impact category of ‘Global Warming Potential’ (GWP) receiving a high level of attention in LCA reports. Single impact assessments and some product labelling of ‘Carbon Footprint of Products’, have further highlighted this category in communications.
The major contribution to the global warming impact category for wool fibre or wool textile is the on-‐farm phase due to enteric methane emissions, with a secondary contribution from methane and nitrous oxide from dung and urine. A major barrier to interpretation of LCA studies and to any comparative analysis is whether these emissions are included or excluded from the assessment. Barber and Pellow (2006), Brent and Hietkamp (2003) and Turley et al. (2009) did not include methane and nitrous oxide emissions. The carbon dioxide emissions estimates were consequently low, 0.985 kg CO2 per kg greasy wool or 1.655 kg CO2 per kg wool top for the New Zealand study (Table 11) and 11.2 kg per kg dyed two-‐fold yarn product for the South African study (Brent and Hietkamp, 2003).
Most LCA studies do include the non-‐CO2 greenhouse gas emissions from sheep digestive processes and manure and in these, enteric methane emissions form the largest contribution to global warming potential for wool. Further where comparisons between wool and other fibres, both natural and synthetic, are made, inclusion of enteric methane emissions means that wool will consistently have the highest GWP impact.
The difficulty in interpretation of a single figure ‘Carbon Footprint of a Product’ has been highlighted by the work of Eady et al. (2010) who clearly demonstrated the effect of choice of allocation method on the quantification of GWP as well as other impact categories in LCA studies. Eady et al. (2010) found that using economic allocation of resource use and inputs gave a result of 26.3 kg CO2-‐e per kg product (1 kg greasy wool ) while biophysical allocation based on resource use derived from a consequential LCA analysis gave a value of 33.7 kg CO2-‐e per kg product. These data are for a specific farm study in Western Australia. Based on economic allocation for a similar assessment of a New South Wales case study farm the GWP was 31 kg CO2-‐e per tonne greasy wool. The results for
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Merino wool from the Australian study were markedly higher than for New Zealand Merino wool because the former includes emissions of enteric methane in the estimate of total greenhouse gas emissions on-‐farm. This difference is shown in Figure 11 to illustrate the danger of trying to compare values from different LCA studies without consideration of methodological issues.
Figure 11. Results for the GWP impact category for Merino wool estimated in five LCA studies illustrate the range in values that arise as a result of methodological differences. Results are expressed as kg CO2-‐e per kg wool top (1) or kg greasy wool (2, 3, 4 and 5). The estimates are from the following reported assessments:
1. Barber & Pellow (2006) New Zealand Merino wool top using biophysical (mass) allocation; excludes enteric methane.
2. Barber & Pellow (2006) New Zealand Merino greasy wool using biophysical (mass) allocation; excludes enteric methane.
3. Eady et al. (2009) Australian Merino greasy wool using economic allocation; includes enteric methane.
4. Eady et al. (2010) Australian Merino greasy wool using economic allocation; includes enteric methane.
5. Eady et al. (2009) Australian Merino greasy wool using biophysical (mass) allocation; includes enteric methane.
An example for carpet production in the Netherlands shows 64 kg CO2-‐e per 1m2 carpet (Table12; Potting and Blok 1995).
4.4.2.3 Results for the impact category of Land Use
Land use was assessed in only a few studies. As for GWP, it is an impact category for which wool scores poorly compared to other fibres, especially synthetic fibres where land use is negligible (e.g. Turley et al. 2009).
For New Zealand carpet land use ranged from 48.5 to 103.8 m2per year per 1m2 with differences reflecting differences in the intensity of production. For Australian wool production it has been estimated that there is a more than 3 fold higher land use for pastoral production than for intensive grazing in the high rainfall zone. However, as noted earlier (Section 4.3.4), these differences do not
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reflect the degree of negative environmental impact. Low stocking rate extensive grazing in the pastoral zone can have little if any negative impact and represents a sustainable use of land not suitable for other productive purposes.
4.4.2.4 Results for the impact category of Water Use
LCA methodology for quantifying water use is less well-‐developed than for most other major impact categories. In addition, there are few reliable data for the on-‐farm phase and estimates of the water required for sheep for drinking and for irrigating pasture or feed crops where this occurs. In pastoral zones, production normally relies on rain water and on-‐farm natural (e.g. creeks) or engineered (e.g. farm dams) water storages but consumption is seldom measured directly.
Few fibre or textile LCA studies have comprehensively assessed water consumption across the full life cycle. As discussed in Section 4.3.3, results for the water use impact category are highly dependent on data availability and methodology selection, e.g. for estimated drinking water for sheep, whether an offset for water returned to soil as urine is included and allowing for evaporative loss from on-‐farm water storages (which can add in the order of 25% extra to intake estimates).
4.4.2.5 Comparative LCA studies
Several studies have attempted to compare the environmental impact of various fibres, often with a view to influencing consumer choice. Kviseth and Tobiasson (2011) state that ‘When comparing different fibres, it is necessary to consider that they are different products with different production processes, uses and maintenance.’ They emphasise that for comparisons between fibres to be valid, the entire life cycle from cradle-‐to-‐grave should be considered. However, this is often not the case (Figure 10). In the ‘MADE-‐BY’ benchmarking comparisons, only the supply chain up to processed fibres for spinning was considered. In addition, comparisons are not valid where different systems boundaries or functional units are used.
Turley et al. (2009) in a comprehensive review completed for DEFRA in the United Kingdom concluded that further research is required to fill data gaps and verify current understanding to a level that allows direct comparisons between fibres. Consistency in methods, scope, data gathering, and analysis techniques will be key to providing a strong evidence base for best practice LCA, that can be used by industry and consumer-‐focussed applications to make informed choices about product sustainability.
Some characteristics of wool production will dominate its environmental impact relative to alternative fibres as calculated in LCA studies using current methodologies:
• Greenhouse gas emissions (GWP) will be relatively high. This is predominantly methane produced in the digestive process of ruminant animals like from sheep. Note here that some studies have not included enteric methane in the study (e.g. Turley et al. 2009, Barber & Pellow 2006).
• Land use will be high, especially in comparison with production of synthetic fibres and will be highest for extensive pastoral sheep farming where impacts on ecosystem functionality are arguably lowest, and may in fact be positive rather than negative compared with any other
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use for those grazing lands. Hence, while on a simple land area score wool rates high, extensive sheep grazing at low stocking rates uses land that is mostly not suitable for other production purposes and can provide positive benefit through management by pastoralists. In addition, it could be argued that comparison between land use for natural fibres and synthetics would be valid only if the full land use to produce the vegetation in ancient times (Cretaceous period) as inputs to acrylic, nylon or polyester feedstocks and the forests needed to produce regenerated cellulostics such as tencel or rayon were similarly counted.
• Water use will be high in the in-‐use (wear) stage for textiles but data are highly uncertain as they depend on the practices of many individuals. Fabric production (dyeing and finishing) can also have a significant water use impact. However, for wool the on-‐farm phase will be a major contribution to the total life cycle water use reflecting drinking water for sheep – a highly uncertain number in current LCA studies and one where the real environmental impact is likely to be low, especially in pastoral dryland production systems.
• Laundry and maintenance are a significant proportion of energy use over the life cycle of garments and wool generally rates favourably compared to synthetic fibres in the use phase.
• Chemical and pesticide loss during wool processing are significant but technologies for managing these emissions are available.
In summary, the 9 wool LCA studies listed in Tables 9 and 10 provide a range of approaches and data collections that could be refined in future under a harmonised methodology to provide more useful information on the environmental performance of wool and to inform strategies to make improvements in the future.
5 Gaps in Knowledge and Data
5.1 LCA approaches
This review of published LCA studies for wool reveals the high degree of variability in methodologies applied and significant data gaps which limit capacity to interpret or to compare results from different studies. It should be noted that LCA was not developed as a tool for comparison of alternative products and is more suited to tracking improvements in efficiency and environmental performance within a supply chain e.g. over time. Four main factors were identified as contributing to the limitations in wool LCA studies to date:
• Data sources may be inaccurate, out-‐of-‐date, inappropriately extrapolated from a different and dissimilar region, or not representative of the production system being assessed, e.g. as used in a national or global representative LCA ;
• Critical methodological assumptions are not appropriate for wool fibre or textiles; • The LCA practitioner is inexperienced in applications of life cycle approaches to natural or
agricultural systems and is unaware of the need for consideration of aspects of diversity and processes different to those used for industrial products;
• Interpretation of the result is incorrect due to lack of knowledge of wool supply chains or because reports do not provide sufficient detail of critical assumptions e.g. functional unit
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description or allocation method and, as a result, communication to consumers and other stakeholders is misleading and/or confusing.
One or more of these four sources affects each of the LCA studies for wool to a greater or lesser extent. Improvements are being achieved over time but as yet caution is recommended in application of the results of LCA to influencing decisions by consumers or other stakeholders. LCA does have a role in assisting an industry to monitor its environmental performance including by identifying points in a supply chain to target for efficiency improvement and to document change over time in impact through a range of indicators. Thus at the present state of development of LCA approaches it appears best suited to internal reporting rather than comparative assertions due to the potential for misinterpretation by non-‐experts.
The discussion of gaps in knowledge and data below is intended to provide support for development of a research program to address the current limitations in wool LCA studies and contribute to future improvements in the usefulness of LCA in environmental impact reports.
5.2 Data sources and data quality
LCA studies require a large amount of data and the accuracy of the results depends on the quality of the data used as inputs to the modelling. For wool, different agricultural systems and individual farms manage resources such as energy, water and land differently and the purpose of the assessment will determine the scale for the life cycle inventory data. Industries or organisations conducting or commissioning LCA studies should aim to access best available up-‐to-‐date data that are sufficiently disaggregated to adequately capture the processes contributing to the environmental impact. It is critical that all significant input assumptions are documented with the LCA to avoid misinterpretation and to facilitate future updates.
5.2.1 Specific supply chain data
Specific supply chain LCAs will require collection of data on-‐site. This can be an expensive and time-‐consuming exercise but is critical where the LCA is intended to provide benchmarking and allow for monitoring of continuous improvement in environmental performance of the supply chain.
Individual farm financial records and documentation coupled with farmer knowledge of practices such as fertiliser applications are a valuable source of data. Inputs to a farm operation include water (‘blue water’ from bores, streams, irrigation channels, farm dams and (where used) reticulated water supplies), fertiliser, fodder, chemicals, fuel and electricity. Purchase of seed, rams, sheep, and contractor inputs should also be considered. However, there are frequently missing elements in on-‐farm data requiring in-‐filling with averaged values or inferred results from expert knowledge. An understanding of optimal data averaging periods will assist in more robust time series, particularly where production is affected by variability in climate or markets.
Calculation of enteric methane emissions, a large contribution to the GWP environmental impact for sheep, frequently relies on averaged emissions factors for different animal types or even a single factor simply multiplied by the number of animals on a property. Methane emissions are known to vary with quality and digestibility of feed, the size of the animal and factors such as lactation. Use of individual animal characteristics is time consuming and these data are unlikely to be available in the majority of LCA studies. However, more detailed data will improve the accuracy of the estimated
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global warming impact and are preferable if the goal is to monitor and document continuous improvement. Accurate reporting of emissions from sheep also requires data for manure management, particularly for feedlots. Emissions from dung and urine in extensive dryland pasture production systems are negligible especially in semi-‐arid and arid regions such as much of Australia’s pastoral region.
Fertiliser use is an important consideration in LCA for on-‐farm assessments due to the energy, resources and water used to manufacture and transport it, the fuel used to spread it on the farm and because nitrogenous fertilisers such as urea can result in significant emissions of the strong greenhouse gas, nitrous oxide which is 298 times as strong a greenhouse gas as CO2 as presented in the IPCC Fourth Assessment Report (Solomon et al. 2007). Fertiliser may be applied to pastures or to feed grains.
Important gaps in knowledge for on-‐farm processes include the rates of nitrous oxide (N2O) emissions from nitrogenous fertilisers under different irrigation or rainfall regimes, rates of methane emissions from sheep on different diets and supplements and what happens to the methane following expulsion by the animal.
5.2.2 National or global representative LCA studies
Major sources of data for broad LCAs are national statistics and publications. The quality, level of disaggregation and time frame of these data collections vary between countries and especially between developed and developing countries. Regional differences in agricultural production systems can make a very large difference to the inputs and emissions associated with an enterprise such as wool growing.
Data on energy and water use remain an important knowledge gap for the wide range of sheep farming and wool processing and production systems around the world. Water use is an impact category for which methodology as well as data are critical needs for studies intended to inform a process of improvement in environmental performance and also for those intended to be communicated as comparative studies. It is difficult to measure the total amount of water consumed to make a product, but records for the processing and manufacture stages are generally more reliable than those for the on-‐farm or use stages within the supply chain. There is high uncertainty in the on-‐farm stage where regional and climatic conditions and also farm management practices will have a very large impact on water intake by sheep. Results from different studies cannot be compared or even interpreted reliably without agreed methodologies for treatment of such issues as evaporative loss from on-‐farm storages (e.g. farm dams that collect rainfall through natural run-‐off), ‘brown’ water (return of urine to the soil), and respiratory loss from sheep.
For the range of scales for which LCA studies are conducted, there remain significant gaps in data and an understanding of data quality, uncertainty, scale and timeframe. Due to the lack of accurate, comprehensive data on a global scale for the diversity of wool supply chains, global wool LCA results have a very high uncertainty. Nevertheless, it appears likely that attempts to conduct representative LCAs for alternative fibres such as reported by ‘MADE-‐BY’ (2011) and DEFRA (Turley et al. 2009) will continue. Therefore, industry would benefit from being able to provide improved data and suitable globally applicable guidelines for broader assessments. Life cycle inventories also require
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investment in documentation of metadata to facilitate more accurate and consistent assessment of environmental impacts of a range of products.
5.3 Methodology
Sections 3 and 4 of this review have described in some detail critical unresolved issues that are affecting our ability to interpret LCA results and to understand differences in results presented for the same product, e.g. 1 kg of greasy wool, produced in different regions or types of production systems, and to interpret comparisons between products such as natural and synthetic textiles.
ISO 14040:2006 and ISO 14044:2006 provide guidance on conducting LCA studies but the guidance is necessarily generic to cover a very wide range of industrial and agricultural products and services. There is, therefore, scope for different assumptions within the Standards. The value of LCA as a tool for assessing the environmental impact of wool would be improved if there were specific rules (‘product category rules’) to guide more consistent application of the international standards. Issues for which guidelines could improve consistency include but are not restricted to:
• Systems boundaries for full (cradle-‐to-‐grave) and partial (cradle-‐to-‐gate) wool LCAs, including methods for treatment of recycling and re-‐use of a product such as a woollen garment.
• Functional unit, and requirements for specifying the unit to enable comparisons, e.g. 1 kg wool (greasy or clean and how to compare) or 1 m2 carpet (specifying weight and with or without backing materials).
• Allocation – existing studies have varied widely in whether environmental burden is shared with co-‐products, and the type of allocation e.g. biophysical (mass) or economic.
• Land use – whether to include land use for sheep grazing and how to indicate land value and potential for alternative uses.
• Water use – resolution of alternative accounting methods e.g. virtual water, diverted or engineered water and treatment of brown water (sheep urine).
Gaps relating to some key questions are discussed below to illustrate the needs for research or methodology development required to improve the value of LCA studies for wool supply chains.
5.3.1 Allocation in wool supply chains
Capacity to interpret the results of LCA studies and differences between studies has been hampered by use of alternative allocation criteria and inadequate documentation of whether and how allocation was done. The main alternatives have been (1) no allocation, (2) biophysical basis or (3) economic basis. Results from Eady et al. (2010) show that results using mass vs economic allocation can differ significantly.
Reaching an agreed approach will require resolution of the difficulties introduced to allocation methods by:
• volatility in the price of both wool and meat products from sheep – affecting primarily economic allocation;
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• seasonal climate impacts – affecting choice of averaging periods for some data and flock structure; and
• fluctuations in production of different co-‐products (e.g. beef, grain, sheep meat) in mixed farming systems.
As an example, Eady et al. (2010) estimated that where sheep feed on stubble after grain harvest it has been estimated that in the order of 6% of the grain (unharvested) is utilised by sheep. This proportion of the fertiliser burden should therefore be allocated to wool and sheep meat production for the period of stubble grazing. Similarly allocation of the methane burden between wool and meat is complex. Relative commodity values have been used as the basis for economic allocation in some studies (e.g. Van de Vreede and Sevenster, 2010), but this relies on production data from the flock and requires averaging to reduce the impact of year-‐to-‐year management decisions related to season and price. The Australian national greenhouse gas accounts estimate an intensity ratio between wool and meat of 1.5:1 and apply this to the national flock. In reality, the value is likely to vary widely with breed e.g. Merinos vs dual purpose breeds and management practice which will vary between and within regions.
5.3.2 Land use
Three outstanding methodological issues relating to the treatment of land use in wool LCAs are: (1) how to account for the quality of land and potential for alternative use other than wool production; (2) whether the resource allocation impact should include direct land use change or direct and indirect land use change; and (3) whether carbon sequestration in vegetation and soils on sheep farms should be credited against the emissions from the stock. There is currently no resolution of these challenging questions.
Land use is an indicator that is intended to represent the damage to ecosystems associated with human land occupation over a certain period of time but this definition is not a good measure of the impact of extensive sheep grazing. The area used for extensive grazing of sheep is large but is frequently natural grasslands or steppe – land that is not suitable for other production uses and which is left relatively undisturbed where stocking rates are low. In many regions there is strong evidence of the long-‐term sustainability of good management practices and it is incorrect to assume that a simple record of total land used for sheep farming equates to a proportional negative environmental impact.
Land use change could be treated as in the draft ISO carbon footprinting standard (ISO DIS 14067) but application to agricultural LCA studies has yet to be tested fully. The ISO DIS 14067 carbon footprinting standard states that “when significant, the GHG emissions and removals occurring as a result of direct land use change shall be assessed in accordance with the goal and scope of the study using internationally recognized methods such as the IPCC Guidelines for National Greenhouse Gas Inventories.” To meet this requirement data on the timing of land clearing and the type of vegetation present before clearing are required. Indirect land use change is even more difficult and the ISO DIS 14067 states that “Indirect land use change shall be considered in [Carbon Footprint of a Product] CFP studies, once an internationally agreed procedure exists, noting that there is on-‐going research to develop methodology and data.”
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Carbon sequestration is another area where methodological guidance is currently inadequate for LCA studies. ISO DIS 14067 recommends that in carbon footprinting studies, “in the absence of land use change and when significant, the GHG emissions and removals occurring as a result of soil carbon change should be assessed and reported separately using internationally recognized methods such as the IPCC Guidelines for National Greenhouse Gas Inventories.” The time period for maintaining sequestered carbon is a topic of debate in both policy and research arenas. Again this is an evolving methodology development for agricultural LCA studies, and research into the impact of including soil carbon sequestration is needed as international accounting moves towards greater more comprehensive treatment of managed lands and greater acceptance of sequestration offsets.
5.3.3 Water use
Water use assessment in LCA studies is currently the subject of debate in the scientific literature and amongst LCA practitioners. In particular, for the on-‐farm phase of the life cycle there are a number of different methods being applied and these alternatives give an enormous range of water use figures spanning two orders of magnitude. Three methodologies underpin many of the studies:
• Virtual water was developed to quantify embedded water in tradeable commodities. It includes ‘blue water’ or liquid water that may be sourced from surface or groundwater which is the contestable water used on-‐farm and in other phases of the life cycle of wool garments and which is sometimes offset for ‘brown water’ or water used and returned (e.g. urinary water) . Virtual water also includes two other classes of water: ‘green water’ which can be thought of as the ‘soil stored moisture from rainfall’ or evapotranspiration water; and ‘grey water’ as an indicator of freshwater pollution that can be associated with the production of a product over its full supply chain. Virtual water is closely related to the concept of water footprinting which may also included a weighting index to reflect the regional water stress. The water footprint of a product is an empirical indicator of how much water is consumed and polluted, when and where, measured over the whole supply chain of the product.
• Water engineering which is based on calculating the water balance between inputs and outputs in a defined system. These systems vary in complexity and data requirements with the scale and activities. An example of a water balance approach is shown in Figure 12 from Peters et al. (2010) but many studies do not clearly describe the accounting procedures, e.g. whether they account for return of urine to the soils.
• LCA water assessment and reporting as an impact category has been carried out in relatively few studies. The definition of water use here may be similar to that used in national statistics in some countries such as Australia as extracted or diverted water, i.e. water that is taken from a surface or groundwater flow that, as a result, is no longer available for alternative use. It may include the concept of sustainable use by expressing water removed or extracted as a percentage of sustainable yields.
A major ongoing point of debate is whether ‘green water’ should be included in impact assessment. Green water is the major source of water in agricultural systems and resolution of this methodological question is critical to developing suitable impact categories and indicators for use in LCA studies for wool and other commodities.
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Figure 12. Example of an annual water balance for a livestock production system (an organic beef cattle production system in Victoria, Australia) from Peters et al. (2010).
5.4 Guidelines for LCA practitioners and communicators
There is not a comprehensive set of guidelines or rules for application of LCA methods to wool. The concept of ‘Product Category Rules’ in LCA terminology is intended to provide for such guidance to ensure consistency in results for a particular product. Wool Product Category Rules would in part overcome the inconsistencies that arise through different interpretations of methodology standards. This is a gap that could be overcome through industry investment but would firstly require resolution and agreement of outstanding methodological issues and an agreed protocol for data and metadata treatment, including reporting of uncertainty (See sections 5.2 and 5.3).
5.5 Interpretation of LCA Studies
There remains inadequate understanding amongst industry and environmental stakeholders on how to interpret LCA results and present clear messages for consumers and other interest groups. The goal should be to report in a way that does not over-‐ or under-‐state the outcomes and that is not biased. Correct interpretation of LCA results depends on the study being representative of the production system being assessed. It also requires that input data are adequate for the goal and scope of the study. Where data are not available, assumptions have to be made, but to date many published LCAs have not adequately documented processes for deriving data or assuming values to fill gaps.
6 Conclusions and Recommendations
This review reveals that there are significant unresolved issues for accounting for environmental impacts such as energy use, water use, land use and greenhouse gas emissions in agricultural production systems, and specifically in wool supply chains. Life Cycle Assessment provides a framework that contributes to the capacity to understand environmental impacts and more
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accurately monitor and report them. However, the diversity of wool production systems globally means that use of LCA as a tool to report an ‘average’ impact or to enable comparative assertions regarding the environmental credentials of alternative fibres is not appropriate and, indeed, will likely be misleading.
Life Cycle Assessment (LCA) is a tool that was developed to quantify the impacts of industrial processes over their full life from raw material inputs to disposal of a manufactured product. Life cycle approaches remain a useful tool. For example, by considering the full supply chain and multiple impact categories, LCA can assist in ensuring that activities to improve environmental performance at one point in production do not result in unintended, negative outcomes elsewhere in the system or result in perverse outcomes for another environmental impact. When done well, LCAs for specific supply chains can offer insights into ‘hot spots’ for environmental impacts along the supply chain and provide a tool for monitoring performance over time and promoting continuous improvement.
It is likely that LCA approaches will continue to be used to provide information to consumers and other stakeholders and possibly to respond to market pressures (or opportunities) that would require supply chain quantification of environmental performance and possibly labelling of products. Until outstanding methodological issues are resolved communication and reporting of LCAs will remain susceptible to misinterpretation, and this is particularly relevant to agricultural LCAs.
Simplified broad assessments, e.g. a global wool LCA for use in a comparison of alternative natural and synthetic fibres or garments, has limited value due to its inability to communicate accurately and fairly the environmental impacts meaningfully for the great range of production systems around the world. Sheep farming covers a very wide range of geographical and climatic conditions and farm practices and there are significant differences in technologies and efficiencies for processing and manufacture. Taking a ‘worst case scenario’ as in the study by MADE-‐BY (2011) biases the LCA results against the majority of more efficient supply chains. This, in turn, affects interpretation and communications intended to influence consumer choice.
This review concludes that it is currently difficult to provide a single defensible quantification of the environmental impact of wool from existing published LCAs. This is unlikely to change in the short-‐term as more accurate assessment will require significant improvements in data availability and quality, and resolution of outstanding methodological issues and agreement on a set of consistent rules that can be applied by LCA practitioners. To facilitate the pathway towards these outcomes, recommendations are provided in the next section on how the wool industry could progress research and LCA development. Consideration of these recommendations is intended to assist in positioning the industry to meet future demands for reporting on environmental impact of wool products.
6.1 Recommendations
The following recommendations are intended to assist in ensuring that LCA approaches develop in a way that facilitates a more accurate representation of the real environmental impact of fibres and textiles and enables fair comparisons of wool with other natural and synthetics fibres.
Recommendation 1: Consolidate existing data, and address data gaps
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The existing LCA studies have highlighted a number of key data gaps. Detailed reanalysis of the datasets from these LCAs is recommended to evaluate the quality of datasets available. In particular efforts should be made to interrogate existing inventories for their potential to help fill those inadequate data and metadata elements identified in Section 5.2, including factors affecting enteric methane and nitrous oxide emissions on-‐farm, fertiliser use for pasture and feed production, water use and energy, water and emissions information for scouring processes and product maintenance. The reanalysis could explore whether there are better and more up-‐to-‐date sources appropriate to the goal and scope of a robust LCA as needed for the wool industry to meet emerging needs for environmental accountability. Where gaps remain it is important to identify specific research needs to address lack of data or deficiencies in quality.
The wool industry in Australia is in a sound position to consolidate the findings of LCA studies to provide defensible information on the environmental impact of wool fibres and textiles that is more robust than assessments currently available. Further analysis of existing datasets should include both publicly released and confidential studies with a view to providing the basis for more useful communications. The three major wool producing categories (high rainfall, wheat-‐sheep and pastoral) in Australia have different features and better characterising the environmental impacts for each of these regions using comprehensive datasets already assembled would assist in benchmarking the current state of knowledge for the industry. It would also provide a baseline for documenting the responsible stewardship of wool growers and for monitoring and reporting on wool industry engagement in actions for continuous improvement in environmental performance.
Recommendation 2: Develop globally applicable guidelines for conduct of wool LCAs
While the environmental performance of wool is most appropriately evaluated at a local or regional scale, it is suggested that the global wool industry could develop agreed guidelines for dealing with the critical assumptions in LCA studies relevant to wool. This would require a cooperative effort similar to that undertaken by the dairy industry to develop a consistent LCA approach. The guidelines should include a documented process for ongoing review and update. Using these guidelines, existing LCAs could form the basis for benchmarking current understanding of environmental impact of wool around the world.
Recommendation 3: Develop a wool industry communication strategy
A communication plan based on LCA could provide factual information and realistic perspectives on the impact categories that will remain high for wool, especially greenhouse gas emissions associated with methane from ruminant digestion and land use for grazing. The plan would also support development of key messages to communicate the positive aspects of the environmental performance of production of wool fibre and textiles.
Recommendation 4: Engage with key stakeholders
The potential for misinterpretation of results of LCA studies will remain high into the near future and yet the demand for assessments of the environmental performance of products, including natural fibres, looks set to continue. Given this dilemma, it seems very likely that the global wool industry
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would benefit from active engagement with major environmental assessment and reporting groups such as MADE-‐BY and DEFRA. Discussions should explore approaches to deal with the complexities and critical assumptions in wool LCAs. Open engagement on opportunities for the industry to cooperate to improve results when publications are shown to present unreliable information due to being based on inaccurate or limited data would assist in insuring against negative public perceptions of wool arising from inaccurate communications.
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References
ANRA (2001). Australian Natural Resources Atlas, Australian Government, Canberra. http://www.anra.gov.au/topics/agriculture/sheep-‐wool/index.html
Barber A. and Pellow G. (2006). Life cycle assessment: New Zealand merino industry, Merino wool total energy use and carbon dioxide emissions. Report by The Agribusiness Group, New Zealand.
Barrett D., Ashton D. and Shafton W. (2003) Australian Wool Industry 2003. Report on the Australian Agricultural and Grazing Industries Survey of Wool Producers, ABARE Research Report 03.5, Canberra.
Biswas W.K., Graham, J., Kelly, K. and John, M. B. (2010). Global warming contributions from wheat, sheep meat and wool production in Victoria, Australia -‐ a life cycle assessment. Journal of Cleaner Production 18: 1386-‐1392.
Brent A.C. and Hietkamp S. (2003). Comparative evaluation of life cycle impact assessment methods with a South African case study. International Journal of Life Cycle Assessment: 8: 27-‐38.
Brown C.G., Waldron S. and Longworth J.W. (2008). Sustainable development in Western China: Managing People, Livestock and Grasslands in Pastoral Areas. Edward Elgar Publishing, Cheltenham, UK.
Brown C., Waldron S. and Longworth J. (2011). The dynamics of the Chinese wool industry: a confluence of economic, social, institutional and environmental factors. Paper presented at 10th European Conference on Agriculture and Rural development in China, Aarhus, 8-‐10 April 2011.
BSI (2011). PAS 2050:2011. Specification for the assessment of the life cycle greenhouse gas emissions of goods and services. British Standards, London, United Kingdom.
Cowell S.J. and Clift R. (1997). Impact assessment of LCAs involving agricultural production. International Journal of LCA 2: 99-‐103.
Eady S., Webb, W.M., Carre A. and Grant T. (2010) Modelling complex agricultural land use systems with multiple food and fibre co-‐products for life cycle assessment. Paper presented for LCA Food Conference 2010.
Eady S. and Ridoutt B. (2009). Setting reporting periods, allocation methods and system boundaries for Australian agricultural life cycle assessment. Proceedings of the 6th Australian Conference on Life Cycle Assessment – Sustainability Tools for a New Climate, Melbourne, February 2009.
Eady S., Street J., Andrews S. and Thompson D. (2009).On-‐farm greenhouse gas emissions and options to offset emissions – an Australian case study.
FAO (2011) (Food and Agricultural Organisation of the United Nations statistics) Accessed Oct. 2011. http://www.fao.org/ag/againfo/home/en/news_archive/2011_Building_a_Global_agenda.html
FAOSTAT (Food and Agricultural Organisation of the United Nations statistics) Accessed April 2012. http://www.fao.org/corp/statistics/
Understanding the environmental impacts of wool: A review of LCA studies
A review prepared for AWI:IWTO Beverley Henry, Agri Escondo Pty Ltd, May 2012 57
Harris, S. and Narayanaswamy, V. Review of Australian and international agricultural life cycle assessment examples. Report prepared for Rural Industries Research and Development Corporation, Canberra, 2009
Henry B.K (2010). Livestock supply chain in a carbon constrained world. Presentation to the WA Farmers 2010 Annual Conference. 25 March 2010.
IPCC 2006 (2006). IPCC Guidelines for the Preparation of National Greenhouse Gas Inventories, Japan.
ISO 14020 Environmental labels and declarations ― General principles, International Standard
ISO 14040 Environmental Management – Life Cycle Assessment – Principles and Framework, International Standard, Second Edition, July 2006.
ISO 14044 Environmental Management – Life Cycle Assessment – Requirements and guidelines, International Standard, Second Edition, July 2006.
ISO/CD 14046 Water footprint – Requirements and guidelines. Draft 2011. ISO 14067 Environmental Management -‐ Carbon footprint of products — Requirements and guidelines for quantification and communication, DRAFT December 2011.
Kviseth K. and Skardal Tobiasson T. (2011). Pulling wool over our eyes: The dirty business of LCAs. Paper presented at the Kea Conference Towards sustainability in textiles and Fashion industry, Copenhagen 26th to 27th April 2011.
MADE-‐BY (2011). Environmental Benchmark for Fibres Report by MADE-‐BY, Version 2.0, July 2011; Research performed by Brown & Wilmanns Environmental, LLC, Santa Barbara, California, USA March 2011 (Condensed Version www. made-‐by.org/)
Ministry of Agriculture and Forestry (MAF) (2011). Situation and outlook for New Zealand agriculture and forestry June 2011. Ministry of Agriculture and Forestry, Wellington NZ.
Murphy R. and Norton A. (2008). Life cycle assessment of natural fibre insulation materials. Final report Imperial College London, Prepared for the NNFCC.
Oerlikon (2008). The Fibre Year 2008/09: A world Survey on Textile and Nonwovens Industry. Arbon, Switzerland: Oerlikon.
Peters, G.M., Wiedemann S.G., Rowley H.V. and Tucker R.W. (2010). Accounting for water use in Australian red meat production. International Journal of Life Cycle Assessment 15: 311-‐320.
Potting L. and Blok K. (1995). Life-‐cycle assessment of four types of floor covering. Journal of Cleaner Production: 3: 201-‐213.
Ridoutt B.G. and Huang J. (2012) Environmental relevance—the key to understanding water footprints. www.pnas.org/cgi/doi/10.1073/pnas.1203809109
Understanding the environmental impacts of wool: A review of LCA studies
A review prepared for AWI:IWTO Beverley Henry, Agri Escondo Pty Ltd, May 2012 58
Ridoutt B.G., Page G., Opie K., Huang J. and Bellotti W. (2012). Assessing carbon, water and land use footprints for beef cattle production in southern Australia. Paper prepared for 8th International Conference on LCA in the Agri-‐Food Sector, Rennes, France, 2-‐4 October 2012. Russell I.M. and Slota I. (2011). Underpinning the environmental credentials of Australian wool. Internal report by CSIRO for Australian Wool Innovation Limited, May 2011 version.
Solomon S., Qin D., Manning M., Alley R.B., Berntsen T. and Bindoff N.L. (2007). 'Technical Summary', in Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, S Solomon, D Qin, M Manning, Z Chen, M Marquis, KB Averyt, M Tignor and HL Miller (eds.), Cambridge University Press, United Kingdom and New York, USA.
Swan P. (2010). Wool as an apparel fibre. In Cottle D.J. (Ed.) International Sheep and Wool Handbook. Nottingham University Press, Nottingham UK.
Turley D.B., Horne M., Blackburn R.S., Stott E., Laybourn S.R., Copeland J.E. and Harwood J. (2009). The role and business case for existing and emerging fibres in sustainable clothing: final report to the Department for Environment, Food and Rural Affairs (DEFRA), London, UK.
Van de Vreede G. and Sevenster M. (2010). Lifecycle environmental impact assessment of textiles – For priority streams in Dutch lifecycle-‐based waste policy. CE Delft, Delft, March 2010.
Watson A.S. (1998). Raw wool production and marketing in China. ACIAR Project 8811, ACIAR, Canberra.
Wiedemann S.G & McGahan, E. J. (2010. Review of water assessment methodologies and application to Australian agriculture, Proceedings of the 7th International Conference on Life Cycle Assessment in the Agri-‐Food Sector, Bari, Italy 2010 p 425-‐430
Woolmark (2007). Australian Wool Production directed to various end uses (%). Woolmark Market Intelligence Unit, Melbourne.
WRI & WBCSD (2011). Greenhouse Gas Protocol Product Life Cycle Accounting and Reporting Standard (2011). http://www.ghgprotocol.org/standards/product-‐standard .
Zhong C. and Yang Y. (1997). China’s textile and clothing exports in the post Uruguay round. In: China and East Asia Trade Policy—Volume IV, Trade reform and liberalisation in China. Pacific Economic Papers 271, Australia–Japan Research Centre, Canberra (Cited by Watson 1998).