Food systems and environmental sustainability: a review of the Australian evidence Working Paper October 2011

Transcription

1 Food systems and environmental sustainability: a review of the Australian evidence Working Paper October 2011 Catie Bradbear and Sharon Friel, National Centre for Epidemiology and Population Health, ANU College of Medicine, Biology and the Environment.

2 Suggested citation: Bradbear C and Friel S (2011). Food systems and environmental sustainability: A review of the Australian evidence. NCEPH Working Paper. Canberra: Australian National University The Australian National University Acton ACT 0200 Australia T E sharon.friel@anu.edu.au

3 Table of contents Introduction... 1 Environmental degradation and the impact on food systems and food security... 1 The food supply chain and its impact on the environment... 3 Greenhouse gas emissions... 4 Water use... 5 Biodiversity... 6 The relationship between foods, food groups and environmental impact... 7 Cereals (whole grain bread, oats, wheat barley, rice, cereal and pasta)... 8 Meat, fish, poultry, eggs, legumes, nuts and seeds... 9 Dairy foods Fruit and Vegetables Discretionary foods Appendix 1: Detailed evidence of the environmental impact of specific food items Cereals (whole grain bread, oats, wheat barley, rice and pasta) Meat, Fish, Poultry, Eggs, Legumes, Nuts and Seeds Dairy foods Fruit and Vegetables Discretionary foods References i

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5 Introduction There is a bi-directional relationship between environmental degradation and food systems. The production and consumption of food in Australia is inextricably linked to the environment. Throughout the whole food system, which involves agricultural production, food processing and packaging, distribution, retail and consumption, environmental inputs such as land, water and energy are used. These processes not only produce food but also other outputs that are returned to the natural environment, such as greenhouse gases, waste water, and packaging and food waste. Each of these contributes to environmental degradation. (1) At the same time, environmental degradation is altering the Australian food system, with implications for yield, quality and affordability. (2) The Australian food system is not only linked to the Australian environment, it is also connected to the broader global environment, through trade in inputs into food production and final products, as well as the potential for environmental impacts, such as climate change, to have global effects. Within Australia, as around the world, there is increasing recognition of the links between food production and the environment. However, when it comes to incorporating this recognition into health policy, governments and policy-makers have been hesitant. This is partly because there is not a clear understanding of the nature of the impact of food production on the environment. A perceived lack of evidence of the impact of the food system on the environment has prevented it from being a key consideration in food and nutrition policy development. In this paper we collate the Australian evidence pertaining to the environmental impact of different food groups and items. Environmental degradation and the impact on food systems and food security Given food production relies on ecosystems ability to provide water, nutrient-rich soils, climate regulation, pollinators, and to help control pests, the increasing environmental degradation experienced around the world is of serious concern. (3) According to the IPCC (2007), the global climate and other life-supporting environmental systems are seriously perturbed and depleted. (4) Climate change-related drought-prone and long-term drying conditions emerging in some sub-tropical regions around the world, higher temperatures, rising sea levels, increasing frequency of flooding, and acidification of oceans are now 1

6 (1, 5, 6) contributing to reduced quantity, quality and affordability of food in many countries. Fresh water supplies are shrinking, with half the world s rivers seriously depleted and polluted. Furthermore, biodiversity, the basis of ecosystem health and ecosystem services, has been more seriously harmed through human activities in the last fifty years than at any other period. (3) Australia is also facing environmental challenges, with an expected increase in average surface temperature of ºC by (7) Overall, there is expected to be an increase in the number of dry days, and also an increase in intense rainfall events in many areas. (7) Water resources are already under pressure, with a lack of water and the absence of natural flooding having a significant impact on many key environmental assets - rivers, streams, wetlands, forests, floodplains and billabongs. (8) Biodiversity in Australia is also at risk, with 1700 species and ecological communities known to be threatened and many ecosystems increasingly vulnerable to collapse. (9) Already the impact of environmental change can be observed on food security, and it is anticipated that in the future, environmental degradation will continue to act as a major constraint on future food production, contributing to reduced quantity, quality and (1, 3, 5, 6, 10) affordability of food in many countries. Environmental change is expected to impact adversely on Australia s food production. For example, the Garnaut Review reports that without climate change mitigation, by mid-century there would be major declines in agricultural production across much of the country, with irrigated production to lose half its annual output. (11) Those agricultural sectors that are considered to be highly vulnerable to the impacts of climate change are the irrigated sheep, beef and grain producers. The next most vulnerable sectors are the dryland sheep, beef and grain producers, as well as some fisheries, though the extent of the vulnerability is unknown for fish. (11) The implications globally and for the Australian public is impaired availability and increased costs of nutritious food. (2) Traditionally one of the world s largest exporters of grain, twice in the last ten years, Australia has been required to import grain. (12) Similarly, the availability and price of fresh fruit and vegetables has been affected by the prolonged drought, with an estimated 33 per cent increase in the price of vegetables and an estimated 43 per cent 2

7 increase in the price of fruit between 2005 and (13) In particular, rising food prices will most affect those on low incomes. (2) Already, the cost of a diet based on national health guidelines is a large proportion 40 per cent of a welfare-dependent family s disposable income. (14) It is therefore possible that environmental change-related pressure which lead to a rise in prices will add an additional financial pressure on households, leading to food insecurity and other health implications. (2) The food supply chain and its impact on the environment Environmental pressures from the food system can take a range of forms throughout all stages of the supply chain (Figure 1). The actual environmental impact at each of these stages will depend upon a range of factors, such as the inputs and processes used in production, the region of production, seasonal variations and advances in food technology. While a standard method of analysis has not been developed to estimate the environmental impact from the food system, there is growing use of tools such as life cycle assessments (LCAs), as well as some use of input-output analysis. Input-output analysis is a technique originally developed for economic analysis, but that has been applied to environmental analysis since the late 1960s. It can be used to assess environmental indicators such as land disturbance, water and energy use. (15) While the specific environmental impacts are often difficult to measure it is clear that food supply, production and consumption in Australia has a direct impact on three environmental indicators: greenhouse gas emissions, water use and biodiversity. The relationship between the food system and these three environmental indicators is now discussed. Figure 1: The environmental impact along the food supply chain 3

8 Source: authors drawing based (16) Greenhouse gas emissions The food system contributes to climate change through greenhouse gas emissions at all stages of production. (2) In 2009/10, agriculture, which is the first stage of the food system, contributed 18.8 per cent to Australia s overall emissions. (17) The extent of greenhouse gas emissions from agriculture is highly dependent on the type of product. However, the major contributor to agricultural emissions is livestock, due to the production of the highly potent greenhouse gas methane. (11) Greenhouse gas emissions can also come from other agricultural sources, such as nitrogen fertilizer, and energy use in irrigation and other on-farm inputs. Greenhouse gas emissions are also released from other parts of the food system, such as processing, distribution, packaging, storage, cooking, and waste. According to Wood et al (2006), Australia has experienced a long-term trend of using more energy for food provision across the whole food supply chain. Not only does this include an increase in the embodied energy of food attributed to primary production, but also an increase in food processing and the transport of food across long food supply chains. (18) Unfortunately, however, little recent analysis exists on the greenhouse gas emissions associated with food processing and manufacturing. One reason for this may be that emissions from these food stages are 4

9 accounted for in other sectors. For example, emissions from food processing facilities, may be accounted for as part of emissions from manufacturing with little further break-down. (19) The food system relies on transportation between each of the stages of production, resulting in the production of greenhouse gas emissions. Since the early 1990s, there has been increasing awareness of the environmental implications of transporting food by carbon intensive methods such as air transport. (20) Food miles the distance food travels from farmer to consumer was originally thought of as a reliable indicator of energy use, and hence carbon emissions, in the food supply chain. However, food miles provide poor quality information about the carbon footprint of food products, only providing an indication of the emissions involved in one part of the production to plate process. (21) A number of aspects of the consumer stage in the food system are also important for greenhouse gas emissions. Food waste is of serious concern for the environment, as it represents an unnecessary use of resources, water and energy in the production, transport, processing and refrigeration of food. Greenhouse gases, in particular methane, are generated in the decomposition of food in landfills. (22) Australians generate an estimated 361 kilograms of food waste per person per year or approximately 936 kilograms per household per year. (22) The Australia Institute estimates that household food waste was responsible for 5.25 Mt CO2-e emissions in 2004 (similar to emissions from the supply of iron and steel). Refrigeration creates greenhouse gases through the use of the energy involved to power the refrigerator as well as the inherent global warming potential of the greenhouse gases. Foods that require refrigeration will have an additional greenhouse gas emissions component compared to those foods that do not require refrigeration. (23) Greenhouse gas emissions are associated with over-consumption of food. As well as the health risks of over-consumption, any food that is consumed above a person s nutritional requirement represents an environmental burden in the form of emissions of greenhouse gases that could have been avoided. Water use The food system, and in particular, primary production, is a large user of water in Australia. In , irrigated agriculture accounted for 65 per cent of Australia s water use, compared to 9 per cent from urban and industrial consumption (24) According to the State of 5

10 the Environment report (2011), groundwater use is a major challenge to sustainable water use in Australia, with large areas of Australia, both urban and rural where groundwater is being used above a sustainable level. (25) The demand for water by agriculture is placing significant pressure on Australia s inland water systems, with the situation exacerbated in Australia by the recent drought. Many crops in Australia are highly irrigated, such as fruit and vegetables, or pasture for feed. Not surprisingly, the level of irrigation water applied has a high impact on the water efficiency of food products. For example: beef, which is a high user of water compared to other agricultural products, is more water efficient without the use of irrigated feed; and wheat is produced with a higher overall water efficiency when a smaller area is (26, 27) irrigated. Water is also used in the other stages of the food cycle. The volume of water used in the Australian food processing industry is approximately 215 gigalitres a year. (28) This includes the water used to process meat, dairy, fruit, vegetables, oil and fat, grains, bakery, confectionery and beverage products. This represents only a fraction (1 per cent) of total water use in Australia. Despite this small proportion of overall water use, compared to other manufacturing industries, water use in food processing accounts for over 30 per cent of water use. (28) Most water does not come in direct contact with the food product, but is used in operations such as cleaning, boiling and cooling. (28) Calculation of the water footprint is often based on three components: blue, green and dilution water. Blue water is surface or groundwater, appropriated largely as irrigation water in farming systems and process water in factories. Greenwater is rainfall intercepted in the root zone by plants. The third component, dilution water, sometimes known as gray water, is the volume of freshwater needed to assimilate emissions to freshwater sources. Biodiversity The food system, largely through primary production, contributes to biodiversity pressures. Agriculture, by necessity, involves an altering of natural vegetation, and as a result, production in agriculture systems has an impact on land and water on and around the farm, with consequences for native biodiversity. Agricultural activities such as the introduction of exotic species, the use of pesticides and fertilisers, and land clearing lead to increased 6

11 vulnerability to pests, changes in climate, habitat loss and destruction and overall biodiversity decline. (19) A significant issue in Australia is the broad-scale clearing of land for agricultural production. While many steps in Australia have been taken to reduce land clearing which has slowed the decline in biodiversity, native vegetation continues to be cleared and modified faster than it is replaced. (29) A net loss of forest (including native and non-native vegetation) of around 260,000 hectares per year occurred between 2000 and 2004 and was primarily attributed to clearing for agriculture as well as urban development. (29) As an example, Victoria has significantly increased the area of land under crops and sown pastures, which has required the clearing of land. As a result, there has been growth in area of irrigated pasture, irrigated crops (especially vines), the cropping of higher rainfall areas and intensive dryland pasture farming in the south. (19) Production of certain foods is considered to place a greater pressure on biodiversity than others. For example, extensive beef and lamb production and dairy production are considered to place greater pressures on biodiversity than other sources of protein. (30) Though not as considerable as the pressures from agriculture, other aspects of the food system also have the potential to place pressures on biodiversity, for example waste from food and food packaging, and waste water can have implications for the health of ecosystems. The relationship between foods, food groups and environmental impact Much of the evidence relating to the environmental impact of different foods is based on primary production and on-farm impacts, with less available evidence for parts of the food supply chain such as processing, retail, consumption and waste. There are limitations to the comparability of findings for some studies, given the often small number of studies per food and the use of different methodological approaches. And despite many studies adopting a life cycle analysis (LCA) approach, there were still a range of methodologies adopted within the LCA model. As well as inconsistency in the activities of the food system that were assessed, there were also differences in aspects such as data source, units of measurement, and even the application and audiences of studies. For example there are inconsistent definitions of water use, with some studies considering rainfall (or green water) as part of 7

12 water use, while others consider only water transferred (blue water). (27) There can also be a variation in the scope of the study, in terms of the stages of the food system that are considered. Some studies might incorporate the environmental impact of manufacturing onfarm machinery, as well as the production of all other on-farm inputs such as fertiliser, while others would only incorporate fertiliser production. Despite difficulties regarding the completeness of the evidence and differing methodologies, we present the evidence that does exist in relation to the impact of different foods on greenhouse gas emissions, water use and biodiversity, categorized according to the food groups in the Australian Guide to Healthy Eating. More detailed evidence on the environmental impact for specific food items in Australia is outlined in Appendix 1. Cereals (whole grain bread, oats, wheat barley, rice, cereal and pasta) An increasing number of life cycle analyses are considering cereal crops, in part, driven by the Grains Research and Development Corporation. A couple of studies have examined a range of crops, such as wheat, rice and barley; and wheat, barley and oats. (27, 31) Most analysis is focused on the primary production process. Of the greenhouse gas emissions from cereals, only wheat and rice are known, with emissions from one tonne of rice lower than emissions from one tonne of wheat, though they are broadly in-line with the results from fruit and vegetables, and lower than meat and dairy. (32) Despite a lower reliance on irrigated water, only around 1.4 per cent of the area planted to cereal crops for grain or seed is irrigated, the evidence suggests that water use for cereals is higher than for fruit and vegetables, while still being lower than the animal source foods. (33) Results varied for each crop, depending on irrigation, however, using those studies that can be compared, on average, rice was found to be the least water efficient. Wheat was the next (27, 31) least water efficient, followed by barley and oats. Little information exists on biodiversity issues, with the exception of rice, which due to its highly irrigated nature at which 100 per cent of the area sown to rice is irrigated (33) has associated issues such as rising water tables, salinisation and water logging. (34) 8

13 Meat, fish, poultry, eggs, legumes, nuts and seeds There is evidence from Australia to suggest that meat production, and in particular beef and lamb, has a relatively large impact on the environment through emission of greenhouse gases, water use and pressure on biodiversity. Most evidence is based on the primary production stage of the food system, with several studies funded by Meat and Livestock Australia. The enteric fermentation process by ruminant animals is by far the biggest contributor to carbon dioxide equivalent emissions in Australia (57.6 MtCO2-e in 2007). (11, 35) Together, beef and sheep account for around 80 per cent of Australia s agricultural emissions. (11) On a unit basis, the available Australian evidence suggests that beef, followed by sheep, have the highest level of emissions per kg of Hot Standard Carcass Weight (HSCW) the weight of the carcass just after slaughter. (32, 35, 36) Beef and sheep produce relatively high emissions compared to meat such as pork, chicken and kangaroo, because they are forestomach fermenting ruminants and produce methane, which has a much greater warming effect than carbon dioxide. (11) Though little evidence currently exists on emissions from kangaroos, decreasing cattle and sheep consumption and increasing kangaroo consumption may help lower Australia s greenhouse gas emissions. (37) Little is known regarding greenhouse gas emissions from fish and other meat alternatives. The impact of meat production on water use is a more difficult to determine, with studies providing broad ranging results, which are unable to provide a conclusive indication of whether one type of meat uses more water. A couple of studies indicate that beef is the highest water user, followed by sheep meat, pork, and poultry, while other studies indicate much more evenness in water use. It is clear that water use in the production of meat will be highly dependent on the use of irrigated feed, with one study finding water use by a supply chain that purchased irrigated feed to be around 15 times higher than a supply chain not relying on irrigation. (26) Regarding biodiversity, beef and sheep production is thought to exert greater pressure on biodiversity, compared to other meats such as goat, kangaroo, pork and poultry. In particular, extensive beef and lamb production have a greater biodiversity impact than were 9

14 they feedlot produced, particularly in indicators such as vegetation clearance, altered fire and grazing regimes and trampling and compaction. (30) Likewise, aquaculture produced fish is considered to have a greater negative impact on biodiversity than wild catch fish. (30) A major environmental concern for the fishing industry is the over-fishing of some species. Though there have been recent improvements, overfishing still exists, with 13 fish stocks classified as overfished in (38) Dairy foods Evidence on the environmental impact of dairy foods is focused on the primary production stage. This stage accounts for around per cent of emissions from the dairy food industry, using large quantities of water in irrigation and exerting pressures on biodiversity. (30, 39-41) The processing stage, which converts raw milk into dairy products such as market milk, cheese and yoghurt has only been examined in a couple of studies. The majority of on-farm emissions from dairy production are enteric methane emissions, though the exact proportion varies depending on the study, ranging from per cent in Christie et al (2008) to 76.2 per cent in Chen et al (2005). (42, 43) Similar to beef cattle, emissions vary depending on feed system. One study found that a total mixed ration feed system, in which the herd is contained in an enclosed area and fed through a cut and carry system of forage, produced the lowest emissions on a unit basis A significant environmental impact from the dairy industry is its high water use, predominantly in the production of feed for dairy cattle. (39) The dairy industry is the largest (44, 45) user of irrigation water in Australia, using 40 per cent of water diverted for irrigation. High use of irrigation can place pressure on the environment and lead to issues such as shallow water tables, salinity and water-logging. (44-46) Overall, the dairy industry exerts a similar degree of pressure on the environment as feedlot beef: not as significant as extensive beef production, but greater than the production of meats such as lamb, kangaroo, pork and chicken. (30) Milk production emits fewer greenhouse gases per tonne of milk compared to the production of one tonne of cheese or one tonne of yoghurt, (39) with UHT milk emitting slightly more emissions and using more energy than market milk. (39, 47) One tonne of yoghurt and one 10

15 tonne of cheese produce around 1.4 and 5.7 times the greenhouse gas emissions in one tonne of milk. Likewise, water use is lower in the production of one tonne of milk, with one tonne of yoghurt requiring around twice as much water as milk, and one tonne of cheese requiring 9.3 times more water than milk. (48) Fruit and Vegetables Compared to animal food products, emissions from vegetables are lower, both overall and on a unit weight basis. Most emissions from vegetables are found to come from electricity use in irrigation, soil fertiliser and post-harvest on-farm activities such as cooling, refrigerating, cleaning and packaging the product. (49) Based on one available set of studies, per tonne of product, green peas (fresh pod) are the highest emitters, followed by asparagus, shelled green peas and broccoli. Despite potatoes, lettuce and tomatoes being the highest overall emitter of greenhouse gases, this is due to their high production, and on a per tonne basis, their emissions are lower. (49) Despite a heavy reliance on irrigation, with 86 per cent of the area of vegetable crops under irrigation, water use of vegetables is also lower than the animal-based foods, though there is great variation between crops. (33) Evidence indicates that asparagus, celery and garlic are amongst the least water efficient, while carrots, lettuce and tomatoes are amongst the most water efficient. (50-57) Little Australian information is available on the environmental impact of fruit, with the analysis that exists focusing most on water use. This evidence on water use comes, in particular, from benchmarking studies, which aim to provide fruit growers with a guide to best practice water use efficiency. Even amongst crops, the evidence varies greatly, with most information available on citrus fruits. There is some limited information available for a couple of crops on greenhouse gas emissions, however, nothing on impact on biodiversity. Furthermore, no evidence is specifically available on environmental impacts over the life cycle of processed fruit products, such as juices, canned or frozen fruits. The overall environmental impact of fruit is sometimes combined with vegetable indicators. For example, the Balancing Act study by Foran et al (2005), contends that greenhouse gas emissions for the fruit and vegetable growing industry are 40 per cent above the food sector 11

16 average. (58) In terms of fruit and vegetable products, the sector includes processing of fruits and vegetables and produces a wide range of frozen, dried, canned and partly prepared products. Weight or volumetric measures are difficult to obtain but major components by financial value include fruit juices (25 per cent), frozen vegetables (17 per cent), preserved fruit (15 per cent), sauces (8 per cent) and jams (7 per cent). (58) The fruit and vegetable products sector provides a reasonable environmental account with greenhouse emissions 5 per cent below average, land disturbance 35 per cent below average and water use over twice the average. (58) Nearly half the water indicator is an indirect effect due to the supply of raw materials from the vegetable and fruit growing sector. Like vegetables, fruit crops in Australia are highly dependent on irrigation water, with 74 per cent of the area sown to fruit trees, nut trees, plantation of berry fruits under irrigation. (33) The available evidence suggests that fruit crops have water use efficiency broadly similar to vegetables. From the evidence, it is not possible to conclusively determine rankings of water efficiency, though the studies would suggest that pineapples are most water efficient, and avocadoes and mangoes are least water efficient (t/ml). (59, 60) Other fruit crops, such as strawberries and pome fruit such as apples and pears are very similar in their water use efficiency. Discretionary foods Relatively few discretionary non-core foods have been analysed for their environmental impact across the life cycle. For the few analyses that do exist, comparison between the products - canola oil; corn chips; Dolmio pasta sauce; and peanut M&Ms would be inappropriate. However, in comparison to similar items that are raw, emissions and water use is high. For example, one tonne of corn chips emits kg CO2-e emissions, which is substantially higher than emissions from one tonne of wheat (304 or 400 kg CO2-e emissions). (32, 61, 62) Likewise, one ML of water would produce 13.2 tonnes of tomatoes, but only 2.8 tonnes of pasta sauce. (51, 53, 54, 56, 57, 63) The LCA case studies by Narayanaswamy et al (2004) found the global warming effect from 1 litre of canola oil to be 7 kg CO 2 -e. It was also found that the greatest contribution to global warming from the production of canola cooking oil was from the pre-farm and farm stage, at 68.8 per cent. In comparison, retail and consumption contributed 17.9 per cent of emissions, 10.6 per cent was from storage and processing, while 2.8 per cent of emissions were from transportation. 12

17 Appendix 1: Detailed evidence of the environmental impact of specific food items Cereals (whole grain bread, oats, wheat barley, rice and pasta) Bread The Grains Research and Development Corporation (GRDC) funded LCA case studies by Narayanswamy et al (2004) on the wheat to bread supply chain, along with barley to beer and canola to cooking oil. This study considered global warming, as well as a range of other impacts, such as resource energy, eutrophication, acidification, and human and terrestrial ecotoxicity. (64) The scope of the study was from pre-farm processes, such as mining and extraction, fertiliser production and chemical production, through to crop cultivation and storage, bread production, packaging, the retail outlet stage, consumption, and expired food and packaging disposal. Transport between phases was also included. The study found the global warming effect of one loaf of white bread (0.681 kg), to be 2.3 kg of CO 2 -e. Of this, around 55 per cent of emissions were found to be from the retail and consumption phase, in particular, emissions from electricity use in retail and consumption. Storage and processing of bread contributed (through electricity use again) 27.8 per cent of emissions; pre-farm and farming contributed 16.5 per cent, while transportation contributed 1.6 per cent of emissions. These results are interesting, because for many food groups, pre-farm and on-farm stages are considered to be the highest emitting phase. Additional research by Murray and Dey (2007) (65) advocates the importance of tracking each social and environmental indicator along the supply chain in order to learn about the full costs of producing a loaf of bread. As well as reporting overall impact for the bread sector, Murray and Dey also report the following environmental results on an intensity basis, for each dollar of final economic output from the bread sector (see table 1). Table 1: Intensity of final output by the bread sector by environmental indicator Indicator Intensity (per $ of final output) Greenhouse gas emissions 206 g CO 2 -e Water use 17.8 L Land disturbance 0.15 m 2 (65) Of total water use, the greatest contribution was the water used in rice farming, with the water embodied in rice products that were purchased by the bread sector. Direct use of water 13

18 by the bread sector, such as an ingredient in bread or for washing and cleaning in bakeries was the second highest ranking use of water. (65) Unfortunately many details concerning the methodology and scope of this study are missing, making it difficult to compare to other studies. Wheat Biswas et al (2008) conducted a life cycle assessment of one tonne of wheat transported to port in South-Western Australia to determine which stage provides the greatest contribution to greenhouse gas emissions. The study considers emissions from pre-farm (such as manufacture of farm equipment and fertiliser and pesticides), on-farm (for example, planting the crop) and post-farm (such as delivery of grain to port) stages. On-farm activities were based on a 12-month field study (from sowing) conducted at the Cunderdin Agricultural College from May 2005 to May 2006, which was divided up into three stages: the first six weeks after sowing; from six weeks to harvesting; and from harvesting to 12 months, which was when the land lay fallow. Overall, 304 kg CO 2 -e was produced during the production and delivery of one tonne of wheat to port. Pre-farm and on-farm stages were the greatest contribution, accounting for 45 per cent and 44 per cent of total emissions respectively, with the post-farm stage accounting for 11 per cent. Overall, the production and supply of fertiliser accounted for the largest proportion of greenhouse gas emissions, at 35 per cent. Also significant sources of greenhouse gas emissions were CO 2 emissions from paddock (27 per cent), and transportation to port and wheat storage (11.3 per cent). (62) Biswas et al 2010 study considered emissions from 1 kg of sheepmeat, wheat and wool production pre-farm and on-farm from a site in Hamilton, Victoria (see the meat section for sheepmeat results). The study found emissions of 0.4 kg CO 2 -e per kilogram of wheat (400 kg CO 2 -e per tonne), which was lower than emissions per kg of sheep meat or wool. While this result is higher than the Biswas et al (2008) study, when taking into account the factor that the Hamilton is grazed briefly pre sowing, and after harvest, which results in the emission of methane from the sheep, the emission from one kg of wheat production at both sites would be similar. (32) Ridoutt and Pfister (2009) (funding from CSIRO, Rural Industries Research and Development Corp, GRDC, Foster s Group Limited, National Foods, Nestle, Goodman 14

19 Fielder, and Kelloggs (Australia Pty Ltd) ) used a method developed by Ridoutt and Pfister in 2009 to provide water footprinting case study evidence on wheat, barley and oats. In the wheat, oat, and barley study, Australian Bureau of Statistics (ABS) data was used to estimate area of the irrigated crops, as well as the volume of irrigation water applied. The wheat, barley and oats cropping systems in NSW are assumed to have no negative impact on the availability of water resources as a result of land use. Summing these measures provides the calculation of the volumetric impact on blue water resources, which is then multiplied by a local water stress characterisation factor derived from the water stress index of Pfister et al (2009). The results for New South Wales varied quite widely, due to the varied use of irrigation in different parts of the state. For example, in the Northern Statistical Division, a region in which only 1.8 per cent of the cropping area is irrigated, the Australian-equivalent water footprint of wheat was 3.15 L/kg. In the Murray and Murrumbidgee Statistical Divisions, however, 8.8 and 10.7 per cent respectively of the region is irrigated, producing water footprints of 182 and 230 L/kg respectively. The New South Wales average Australian-equivalent water footprint for wheat was 86.5 L/kg. (27) Khan et al (2009) compared inputs into and outputs from the production of wheat, rice and barley under different irrigation systems (barley and rice considered below) by converting inputs into energy equivalent units. The indicators examined included water productivity, as well as energy efficiency and energy productivity, irrigation energy ratio and fertiliser/agrochemical ratio). The study was conducted on selected broadacre farms in the Murrumbidgee and Coleambally Irrigation areas, where rice is the dominant crop. To determine water productivity, however, they considered water used, and yield, and found water productivity for wheat to be 1.71 kg per m 3 (1 ML) of irrigation water used. This result is greater than that of rice, but lower than the water productivity of barley. (31) There are also a number of studies that consider water use efficiency of wheat through evapotranspiration the transfer of water as water vapour to the atmosphere from both vegetated and unvegetated land. (66, 67) These studies, however, are largely focused on rainfall. A comprehensive study by Hochman et al (2009) considered water use efficiency (WUE) benchmarking by farmers and the implications of using a surrogate measure of WUE, growing-season rainfall, where they don t have the required soil moisture measurements to determine WUE. The study reports that in the literature, there have been a range of water use efficiency values for wheat, ranging from 3.8 kg/ha of grain for each mm of 15

20 evapotranspiration (68) to 15.8 kg/ha/mm. (69) Using a dataset of 334 wheat crops (including 11 irrigated crops) grown in the winters of , average WUE (evapotranspiration) efficiency was 15.2 kg/ha/mm. The study also found that using growing-season rainfall as a surrogate for evapotranspiration leads to a far less reliable of potential grain yield than that obtained when measurements of soil water at sowing and crop maturity are used also with incrop rainfall to estimate evapotranspiration. (67) This study considers that in terms of the number of crops simulated, the number of years and the geographic spread of data, it is the most comprehensive evaluation of WUE for wheat crops in Australia. (67) Barley Ridoutt et al (2009) found that the Australian-equivalent water footprint of barley in New South Wales was 80.7 L/kg, ranging from 1.42 L/kg in the South Eastern Statistical Division, to 211 L/kg in the Murrumbidgee Statistical Division where a greater proportion of cropping is irrigated. The Ridoutt et al (2009) water footprint for barley was smaller than that of wheat, but greater than the footprint from oats. (63) 97.1 per cent of the water footprint is from irrigation, with 1.8 per cent from farm inputs, and 1.1 per cent from gray water. (27) Khan et al (2009) also found a smaller water footprint for barley than wheat, with water productivity 3.27 kg/m 3 water. (31) No information is available on greenhouse gas emissions or biodiversity impact. Oats Ridoutt et al (2009) also considered the water footprint of oats, finding the New South Wales average to be 65.4 L/kg, a smaller footprint than wheat and barley. Like wheat and barley, however, the results between Statistical Divisions varied depending on whether the area was irrigated, with a range from 3.05 L/kg to 210 L/kg. (27) 94.3 per cent of water use for oats came from irrigation, 3.7 per cent from farm inputs and 2.0 per cent from gray water. (27) No information is available on greenhouse gas emissions or impact on biodiversity. Rice According to Maraseni et al (2009), the level of greenhouse gas emissions from rice farming not only depends on the amount and types of farm inputs, but also varies with irrigation systems and water management practices. (70) The method of flooding rice fields results in cutting off oxygen supply to the soil, resulting in anaerobic fermentation of organic matter 16

21 and thus methane gas production. Maraseni et al (2009) considered greenhouse gas emissions from rice farming inputs and irrigation systems in key-rice growing countries, such as Australia, Pakistan, the Philippines, China, Indonesia and the USA. For Australia, data was collected during from 18 farmers using canal irrigation in the Coleambally Irrigation Area in New South Wales. The study found emissions of 0.18 kg CO2-e per kg of rice yield, which is equal to emissions from rainfed rice in Indonesia, but lower than emissions from the other countries production of rice. (70) The Khan et al (2009) study, already discussed in the context of wheat and barley, also considered water productivity in rice. It was found that 0.56 kg of rice is produced per m 3 of irrigation water used, which is lower that the production of wheat and barley for an equivalent level of water. (31) Water use of rice was also examined by Beecher et al (2006), who undertook a cropping system experiment with the aim of comparing individual crop and total system performance of different rice production methods. The experiment consisted of 5 layout-irrigation treatments, which incorporated different depths, timing and methods of irrigation. Water productivity ranged from 0.55 to 0.68 t/ml, with the flat treatment (in which the bays received three flush irrigations water was ponded for 12 hours then drained before a permanent flood was applied to 15 cms, and maintained between 3 and 5 cms, before being raised to 15 cm, then reduced back to 3-5 cms until draining) providing the best water productivity. (71) According to Humphreys et al (2006) a serious environmental issue in rice growing areas is rising watertables and secondary salinisation and water logging. Ponded rice is a major contributor to watertable rise. Furthermore, shallow groundwaters (often saline) seep into surface drainage systems with the potential to impact adversely on downstream users and regional ecosystems. (34) Meat, Fish, Poultry, Eggs, Legumes, Nuts and Seeds Red meat Greenhouse gas emissions: Beef cattle have high total greenhouse gas emissions compared to other red meats. In 2005, beef cattle accounted for around 58 per cent of Australia s agricultural emissions compared to 22 percent from sheep. (11) In 2008, enteric emissions were 37,819,710 tonnes CO 2 -e from beef cattle, 11,265,140 tonnes CO 2 -e from sheep and 17

22 45,740 tonnes CO 2 -e from goats. (72). A study by Foran et al (2005) suggest that emissions from cattle are 26 times the Australian economy-wide average when measured per dollars of final demand. (58) That being said, there are variations in emissions among different supply chain stages. A life cycle analysis by Peters et al (2010) (funded by Meat and Livestock Australia (MLA)) assessed emissions through the farm, feedlot and processing plant of three supply chains. The supply chains were a sheep meat supply chain in Western Australia, a beef supply chain in Victoria producing organic beef, and a premium export beef supply chain in New South Wales in 2002 and The sheep meat supply chain was found to perform slightly better per kilogram of Hot Standard Carcass Weight (HSCW) than the beef supply chains, with an average of 7.75 kg CO 2 -e per kg HSCW over 2002 and 2004, compared to 9.85 kg CO 2 -e in the Victorian and 10 kgco 2 -e in the NSW supply chains. (35) Grain-finished beef within the New South Wales supply chain was found to produce lower emissions on a unit basis, at 9.9 kg CO 2 -e per kg HSCW compared to the grass-finished beef 12.0 kg CO 2 -e per kg HSCW. The study found this to be due to the more efficient weight gain and superior digestibility of the feed for the grain-fed beef cattle. (35) Another analysis of emissions from sheep meat comes from Biswas et al (2010), that considered pre-farm and on-farm emissions from wheat and wool production as well as sheep meat on subclover and mixed pasture plots. Emissions from mixed pasture sheep meat were lower, at 5.09 kg CO 2 -e per kg of sheep meat compared to 5.56 kg CO 2 -e per kilogram of sheep meat from the sub-clover pasture. (32) These results are slightly lower than the Peters et al (2010) analysis. While overall emissions from goats and kangaroos are low compared to beef and sheep, little information exists on their emissions on a unit basis. (72) A couple of studies indicate that because kangaroos are nonruminant forestomach fermenters they produce less methane (73, 74) compared to cattle and sheep. Water use: The impact of water use on the environment largely depends on the locality of production. The measurement of the water footprint is often based on three components: blue, green and dilution water. Blue water is surface or groundwater, green water is rainfall intercepted in the root zone by plants, and gray water or dilution water is the volume of 18

23 freshwater needed to assimilate emissions to freshwater sources. The increasing demand for water by agriculture is placing significant pressure on Australia s inland water systems. The demand can largely be attributed to the high water use in the red meat industry, with estimates for water use in the cattle industry to be times the economy-wide average of water use. (58) Peters et al (2010) (with funding from MLA) considered water use in the same three supply chains (two beef supply chains from Victoria and NSW, and one sheep meat supply chain from WA) discussed above, and found a large variation in results for water use. Total transferred water (which included irrigation supply, livestock or irrigated feed and reticulated supply), ranged from L/kg HSCW for the Victorian beef supply chain, L/kg HSCW for the WA sheep meat supply chain, and L/kg HSCW for the premium export beef system in NSW. The high water use for the NSW supply chain is in large part due to the purchase of irrigated feed by the feedlot. (26) If considering net water use, which takes the approach of recording water where the discharge is not as high quality as water vapour, there is less variation, with the two beef systems averaging 49 and 41.5 litres per kilogram of HSCW, while the sheep meat system averaged 20 litres per kilogram HSCW (26). It should also be noted that most of the grain and fodder crops used in these three supply chains were produced by dryland cropping, which would influence the results. (26) Biodiversity: Red meat cultivation also has an impact of biodiversity. In considering the impact of red meat on biodiversity, Williams and Price (2010) reviewed over 500 peerreviewed and other sources for MLA to assess the relative pressures of the red meat industry in Australia compared to white meat, plant protein production systems and other protein production systems. (30) Through their interpretation of the literature, they have classed the different protein sources as having either low, medium or high pressure on a range of biodiversity measures relative to each other. The results are shown in the figure below, with extensive beef production receiving the most high pressure results. Feedlot beef is much more moderate in biodiversity pressures, recording mediums in the measures such as vegetation clearance and altered grazing regimes, and lows in measures such as altered fire regimes and trampling and compaction. Williams and Price (2010) consider that the red meat industry, and in particular, beef, has been the biggest contributor to vegetation clearance for grazing management (Figure 1). (30) 19

24 Extensive lamb production is considered to place a medium pressure, while feedlot lamb is considered to place a low pressure on vegetation clearance. Overall, biodiversity pressures from goats and kangaroos are also considered to be low, though both kangaroos and goats are considered to have medium pressure on altered grazing regimes. (30) Figure 1: Potential relative contribution of different protein source to the pressure on biodiversity (30) A continent-wide analysis of total grazing pressure (TGP) in relation to net primary productivity undertaken for the 2006 State of the Environment report compared the grazing pressure of sheep, cattle and kangaroos based on an estimated kangaroo population of 19 million. The study found that cattle contributed 66 per cent of TGP, sheep 30 per cent and kangaroos would contribute 4 per cent. The lamb and goat industries in Australia also contribute to grazing pressure to lesser degrees (75). To date, there has been little analysis of the impacts of the goat and kangaroo harvesting industries on biodiversity. (30) However, Wilson and Edwards (2008) assert that were production to shift away from cattle to kangaroos, there would be a conservation and biodiversity benefit resulting from the ability of kangaroos to adapt to the native environment. (37) For example, Grigg (1995) considers there would be a net reduction in land pressure, which would enable rehabilitation of land systems. (76) There are a number of 20

25 additional studies advocating the biodiversity benefits of greater kangaroo meat production in Australia. Pork and poultry Greenhouse gas emissions: Emissions from pork and poultry make up less of the total emissions from agriculture compared to beef cattle and sheep. (72) A life cycle analysis conducted for Pork Australia by the Rural Industries Research and Development Corporation (36) considered two pork supply chains in Australia: a northern and a southern supply chain. The LCA included feed-milling, on-farm production at the piggery, and meat processing. The results from the pork LCA on greenhouse gas emissions are similar though slightly lower than those for the Biswas et al (2010) sheep meat study, with the global warming potential of the northern pork supply chain found to be 5.5kg CO 2 -e per kg of HSCW, while the global warming potential of the southern supply chain was found to be 3.1 kg CO 2 -e per kg of HSCW (36) Very little is known about emissions from poultry on a unit basis, though a life cycle assessment of the Australian meat chicken industry is currently being undertaken by the Rural Industries Research and Development Corporation. Water: The same pork life cycle analysis outlined above also considered water use through the supply chain, and asserts that water used in pork production is considerably less than for beef cattle production. (36) Blue water usage (water sourced from surface or groundwater supplies; excluding rainfall as an input into feed) was 41 and 49 litres per kilogram of HSCW for the southern and northern supply chains respectively. The overall water footprint, which includes rainfall and blue water usage, was estimated at and litres per kilogram of HSCW for the southern and northern supply chains respectively. (36) According to Foran et al (2005), water use for the pig industry is four times the national economy-wide average, while water use for poultry and eggs is twice the average, though direct water use by the industry is minor. (58). Water is largely used as an input in products upstream, such as in beef products and sugar cane, that then become an input into poultry and egg production (58). Finally, Hoekstra and Chapagain (2007) estimate water use for one tonne of pork and one tonne of chicken to be 5,909 m 3 and 2,914 m 3 respectively (77) 21

26 Biodiversity: Piggeries can generate a number of environmental issues of a different nature to cattle. (78) For example, pigs return more than half the feed they consume as waste, with disposal creating water pollution, eutrophication and phosphate leaching. (78) The biodiversity impact of different protein sources, pork and poultry, are rated as having a relatively low pressure in most categories such as vegetation clearance and altered fire regimes. Overall, however, both outdoor pork and outdoor chicken production are considered to place less pressure on biodiversity than indoor production. A study by Willaims and Price (2010) found that indoor pork and indoor chicken production are both considered to place a medium pressure on biodiversity through pollution and disease and pathogens. (30) The Balancing Act study by Foran et al (2005) reports a less land disturbance compared to cattle, with land disturbance three times the nation-wide average for poultry and eggs, and an average land disturbance for pigs. (58) This is a result of the intensive nature of pork and poultry production. Fish Greenhouse gas emissions: Little is known on greenhouse gas emissions from the fishing industry in Australia. A study of the Galician fishing industry in north-west Spain indicated that offshore fishing was the main fishing activity contributing to emissions from the fishing industry, ahead of deep-sea fishing. Marine intensive aquaculture and coastal fishing showed a similar contribution, while extensive aquaculture was the lowest emitting sector of the fishing industry. (79) It is not clear whether these results would be the same for the Australian fishing industry. Water: Very little information is available on water use in the Australian fishing industry, however Foran et al (2005) consider water use to be 50 per cent below the national average. (58) Biodiversity: A major biodiversity concern for the fishing industry in Australia is overfishing, which can lead to the extinction, or seriously reduced numbers of some fish populations. While there remains little known about fish populations, except in commercial 22

27 fisheries, reporting shows a steady increase in the number of species that have been overfished (38) (Figure 2). Figure 2: Trends in Commonwealth managed fish stocks Source: (38) There have been improvements in the Australian fishing stocks. The number of stocks classified as not subject to overfishing has increased substantially from 12 in 2004 to 58 in 2009 (Figure 3). (80) However, in 2009, 12 fish stocks were classified as overfished and ten 23

28 were subject to overfishing. Three of these stocks are both overfished and subject to overfishing (southern bluefin tuna, jackass morwong and upperslope gulper sharks). (80) Figure 3: Biological stock status classifications as a percentage of the total number of stocks assessed since the classification change in (80) Williams and Price (2010) found varied results in biodiversity pressures from fishing. Pressures from wild catch fishing were generally low, apart from rating high biodiversity pressure in trampling and compaction and direct loss of biota. Aquaculture recorded a more mixed range of low and medium biodiversity pressures. (30) Eggs, legumes, nuts and seeds Greenhouse gas emissions: There is little Australian literature available on greenhouse gas emissions from eggs, legumes and nuts, although eggs have been touched upon above in the context of poultry in the Foran et al (2005) study. There has, however, been some study of the greenhouse gas benefits of growing legumes, due to their ability to fix nitrogen in soils, decreasing the need to use nitrogen fertilisers. (81) Results, however, are mixed, with one study from Australia finding that chickpea did not fix 24

29 sufficient N 2 or mineralise sufficient N from residues either to maintain soil N fertility or to sustain a productive chickpea-wheat rotation without additional nitrogen fertiliser. (82) Water: There is a lack of available evidence on water use in this food category. Water use for egg production has been combined with poultry in the Foran et al study, while Hoekstra and Chapagain (2007) consider water use of eggs production to be 1,844 m 3 per tonne of eggs. (77) Biodiversity: Biodiversity pressures from plant based proteins, such as grains, legumes and pulses, are wide in their spectrum, from low pressure in altered grazing regime and direct loss of biota; medium pressure in vegetation clearance and invasive species; and high pressure in altered hydrology. Overall most pressures are considered low or medium. (30) Dairy foods On-farm environmental impacts Greenhouse gas emissions: Dairy farming contributes moderately to environmental degradation form the dairy industry and accounts for 11.6 per cent of Australia s agricultural greenhouse gas emissions. (11) A number of studies have indicated that the vast majority of greenhouse gas emissions from the Australian dairy industry come from dairy farming; (40, 41) around 85 and 87 per cent of emissions are from dairy farming. On-farm emissions come from a variety of sources, though enteric methane is thought to provide the greatest share. (39) According to the National Greenhouse Gas Inventory, emissions from dairy farming in 2008 were tonnes of CO 2 -e from enteric fermentation and tonnes CO 2 -e from manure management. (72) A life cycle assessment of a representative dairy farm with limited irrigation pastures in Queensland found 76.2 per cent of greenhouse gas emissions to be methane emissions from cows, while 19.7 per cent came from pasture (including from pumped water and fertiliser), and 4.1 per cent from milking and on-farm storage. (42) In contrast, however, Christie et al (2008) (funded through Dairy Australia and the Department of Agriculture, Fisheries and Forestry) found on-farm methane emissions to be per cent of total emissions, depending on the feed system. Of the three dairy 25

30 production feeding systems studied, a total mixed ration feeding system, in which the herd is contained in an enclosed area and fed through a cut and carry system of forage, was found to produce the lowest emissions per tonne of milk solids (12.2 and 12.8 tonnes CO 2 -e per tonne of milk solids, MS). The other feeding systems studied were a low supplementary feeding system, which produced 17.5 tonnes CO 2 -e per tonne of MS, and a high supplementary feeding system, which produced 14.0 and 15.3 tonnes CO 2 -e per tonne of MS (43). These figures are the sum of pre-farm embedded emissions associated with farm inputs and on-farm carbon-dioxide, methane and nitrous oxide emissions. (43) Auldist et al (2006) measured methane emissions from grazing cows in Victoria. They found emissions varied throughout the year, with 36.8 g of methane emitted for 1 kilogram of milk in May, and only 12.9 g of methane per kilogram in September. (83) Meanwhile, Howden and Reyenga (1999) consider that dairy cattle in Queensland produce 1.5 and 3 kilograms of CO 2 -e per dollar at the farm gate for market milk and manufacturing milk respectively. (84) Water use: According to Dairy Australia (2006), the dairy industry s greatest environmental impact is in its high water use, largely in the production of feed for cattle. (39) The dairy industry is the largest user of irrigation water in Australia, and accounts for one-third of the land under irrigation. (45) According to Bethune and Armstrong (2004), the dairy industry uses 40 per cent of water diverted for irrigation (44), while Khan et al (2010), consider the industry uses 25 per cent of Australia s surface irrigation water, and is also a major user of groundwater. (45) According to the Dairy Research and Development Corporation (2001), 57 per cent of dairy farms irrigate their pastures although this figure will vary according to location. (85) The amount of water used on-farm to produce a unit of milk varies considerably. A study in the Goulburn and Murray Irrigation systems analysed on-farm water efficiency, and found that 68 kg of milk was produced from one megalitre of water. (86) A study of irrigated dairy farmers in northern Victoria and southern New South Wales also considered water use efficiency, and found a broad range in results, varying from 25 kg to 115 kg of milk fat and protein produced per megalitre of water. In this study, the high water use efficiency farms produced a similar amount of milk from less water, less land and a similar number of cows. (87) Finally, according to Save Water, the industry average is around 1200 litres of milk per megalitre of irrigation water. (88) 26

31 Biodiversity: Dairy generally exerts medium pressure on biodiversity compared to other protein sources. (30) For example, Williams and Price (2010) considered the pressures on biodiversity from dairy in areas such as vegetation clearance, altered fire regimes, altered grazing regime, and altered hydrology to be greater than that of feedlot lamb, chicken, eggs, and pork, but lower than the pressures coming from extensive beef production. (30) One factor influencing biodiversity which is of particular relevance to the dairy industry is the clearing of land to make way for pasture, with many farms retaining little natural vegetation. (30, 46) Bird (2003) reports that on the average farm, the average area of remnant vegetation was 1 3 per cent, while around 4.6 per cent of the average farm is planted with trees. (46) Another pressure on biodiversity from the dairy industry is its high use of irrigation, which can lead to issues such as shallow water tables, salinity and water-logging. (44, 46, 89) Other biodiversity considerations include: dairy shed effluent disposal; erosion; chemicals from pesticides, biocides and veterinary chemicals, and nutrients in runoff from paddocks to surface water and leaching from paddocks to groundwater. (90) Dairy processing and manufacturing Greenhouse gas emissions: Once milk leaves the farm gate it is taken for processing. Dairy processing accounts for around 13 per cent of both direct and indirect emissions from the Australian dairy industry. (40) A report on the state of the environment in the dairy manufacturing industry estimates that of the sites they surveyed (69 per cent representation), tonnes of CO 2 -e was emitted, equivalent to 94.3 tonnes of CO 2 -e per megalitre of raw milk processed. (39) A 2008 report from the Dairy Manufacturing Industry estimates 146 tonnes of CO 2 -e per megalitre of raw milk processed from thermal energy and electricity use, while a larger estimate which considers emissions from electrical energy, thermal energy, transport (raw milk to site) and forklift use (on site) is 162 t CO2-e per megalitre of raw milk processed (see Figure 4). (40) Figure 4: Energy source contribution to greenhouse gas emissions 27

32 (40) Water use: Compared to on-farm use, water use in dairy processing is low, with a life cycle analysis indicating that 1 per cent of total water use in the dairy industry is used in the processing of dairy products. (47) A study from Dairy Australia (2008) on the dairy manufacturing industry found that in , 1.5 litres of fresh water are used for every 1 litre of raw milk, an increase from 1.3 litres in (40) However, different manufacturing processes for the range of dairy products require different level of water inputs. (40) Biodiversity: Little is currently know of the biodiversity impacts of dairy processing in Australia. The Australian Dairy Manufacturing Industry Sustainability Report (39) states that dairy manufacturers are required to manage a range of pressures. Out of eight environmental issues, water availability and energy efficiency are those issues of most concern. The report goes on to mention that environmental issues seem to be site specific, with variation depending on local environmental conditions, government regulations and the availability of services and resources. (39) Milk Compared to yoghurt and cheese, milk production emits fewer greenhouse gases per tonne of product, as shown in figure 5. UHT milk emits slightly more greenhouse gases, around kg CO 2 -e per tonne of UHT milk, compared to around kg CO 2 -e per tonne of milk. (39) 28

33 Figure 5: Greenhouse gas emissions per tonne of dairy product (39) As table 2 indicates, throughout the lifecycle, the greatest proportion of emissions from market milk come from on-farm impacts, at 52 per cent of emissions. (47) Imported feed (8 per cent) and consumer transport (7 per cent) are also significant sources of emissions. Table 2: Source of greenhouse gas emissions across the life cycle of market milk (per cent) Life cycle greenhouse gas emissions market milk (% total) On-farm energy 4 Imported feed 8 Other farm inputs 6 Raw milk transport 4 Manufacturing 5 Packaging 3 Warehouse 1 Transport to supermarket 2 Supermarket 6 Consumer transport 7 Home refrigeration 2 On-farm impacts 52 29

34 A difference between market milk and UHT milk is also evident in their respective energy uses, and in particular, a greater proportion of energy use from transport for UHT milk compared to market milk. This led to a higher overall energy use per tonne of UHT milk when compared to market milk (figure 6). (47) It is also worth noting that energy use does not follow the same trend as greenhouse gas emissions, as only 13 to 21 per cent of energy use is attributable to the farm, compared to 52 per cent of greenhouse gas emissions. Figure 6: Life cycle energy use per tonne of dairy product (47) (47) In terms of water use, different manufacturing processes also consume varying quantities of water, with milk powder-producing factories requiring less water than fresh dairy products (40). A report from the Dairy Manufacturing Industry found that the average fresh water use per litre of raw milk was 1.6 litres for milk, which was lower than the average for cheese and whey, though higher than the average for milk powders. (39) In contrast, Feitz et al (2007) indicates that milk powder requires almost seven times as much water to produce as milk. (48) The difference in these results for milk powder is likely due to the different capacities for factories producing milk powders to re-use water through their production processes. Milk and cream use approximately the same amount of water input per tonne of output, although cream uses substantially more raw milk in production. 30