302 research outputs found

    The green, blue and grey water footprint of farm animals and animal products. Volume 2: Appendices

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    Contents Appendix I: Feed conversion efficiencies – in kg of feed (dry mass) per kg of output – per animal category and region Appendix II: Estimated consumption of feed per animal category and world region (103 ton dry mass/yr) Appendix III. Estimated consumption of feed per production system and world region (103 ton dry mass/yr) Appendix IV. Drinking and service water footprint per animal Appendix V. Water footprint of animals and animal products (m3/ton). Period 1996-200

    Spatially and temporally explicit water footprint accounting

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    The earth’s freshwater resources are subject to increasing pressure in the form of\ud consumptive water use and pollution (Postel, 2000; WWAP, 2003, 2006, 2009).\ud Quantitative assessment of the green, blue and grey water footprint of global production\ud and consumption can be regarded as a key in understanding the pressure put on the global\ud freshwater resources. The overall objective of this thesis is, therefore, to analyse the spatial\ud and temporal pattern of the water footprint of humans from both a production perspective\ud and a consumption perspective. The study quantifies in a spatially explicit way and with a\ud worldwide coverage the green, blue and grey water footprint of agricultural and industrial\ud production, and domestic water supply. The green, blue and grey water footprint of national\ud consumption is quantified and mapped for each country of the world. The study further\ud estimates virtual water flows and national and global water savings related to international\ud trade in agricultural and industrial goods. Next, the study assesses the blue water scarcity\ud for the major river basins of the world for the first time on a month-by-month basis, thus\ud providing more useful guidance on water scarcity than the usual annual estimates of water\ud scarcity. The study also contains five case studies: two specific product water footprint\ud studies, two specific country water footprint studies and one water footprint study on a\ud specific product from a specific region

    Essays on Human and Social Capital Formation

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    Global gray water footprint and water pollution levels related to anthropogenic nitrogen loads to fresh water

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    This is the first global assessment of nitrogen-related water pollution in river basins with a specification of the pollution by economic sector, and by crop for the agricultural sector. At a spatial resolution of 5 by 5 arc minute, we estimate anthropogenic nitrogen (N) loads to freshwater, calculate the resultant gray water footprints (GWFs), and relate the GWFs per river basin to runoff to calculate the N-related water pollution level (WPL) per catchment. The accumulated global GWF related to anthropogenic N loads in the period 2002–2010 was 13 × 1012 m3/y. China contributed about 45% to the global total. Three quarters of the GWF related to N loads came from diffuse sources (agriculture), 23% from domestic point sources and 2% from industrial point sources. Among the crops, production of cereals had the largest contribution to the N-related GWF (18%), followed by vegetables (15%) and oil crops (11%). The river basins with WPL > 1 (where the N load exceeds the basin’s assimilation capacity), cover about 17% of the global land area, contribute about 9% of the global river discharge, and provide residence to 48% of the global population

    The green, blue and grey water footprint of farm animals and animal products. Volume 1: Main Report

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    The projected increase in the production and consumption of animal products is likely to put further pressure on the globe’s freshwater resources. The size and characteristics of the water footprint vary across animal types and production systems. The current study provides a comprehensive account of the global green, blue and grey water footprints of different sorts of farm animals and animal products, distinguishing between different production systems and considering the conditions in all countries of the world separately. The following animal categories were considered: beef cattle, dairy cattle, pig, sheep, goat, broiler chicken, layer chicken and horses. The study shows that the water footprint of meat from beef cattle (15400 m3/ton as a global average) is much larger than the footprints of meat from sheep (10400 m3/ton), pig (6000 m3/ton), goat (5500 m3/ton) or chicken (4300 m3/ton). The global average water footprint of chicken egg is 3300 m3/ton, while the water footprint of cow milk amounts to 1000 m3/ton. Per ton of product, animal products generally have a larger water footprint than crop products. The same is true when we look at the water footprint per calorie. The average water footprint per calorie for beef is twenty times larger than for cereals and starchy roots. When we look at the water requirements for protein, we find that the water footprint per gram of protein for milk, eggs and chicken meat is about 1.5 times larger than for pulses. For beef, the water footprint per gram of protein is 6 times larger than for pulses. In the case of fat, we find that butter has a relatively small water footprint per gram of fat, even lower than for oil crops. All other animal products, however, have larger water footprints per gram of fat when compared to oil crops. The study shows that from a freshwater resource perspective, it is more efficient to obtain calories, protein and fat through crop products than animal products. Global animal production requires about 2422 Gm3 of water per year (87.2% green, 6.2% blue, 6.6% grey water). One third of this volume is for the beef cattle sector; another 19% for the dairy cattle sector. Most of the total volume of water (98%) refers to the water footprint of the feed for the animals. Drinking water for the animals, service water and feed mixing water account only for 1.1%, 0.8% and 0.03%, respectively. The water footprints of animal products can be understood from three main factors: feed conversion efficiency of the animal, feed composition, and origin of the feed. The type of production system (grazing, mixed, industrial) is important because it influences all three factors. A first explanatory factor in the water footprints of animal products is the feed conversion efficiency. The more feed is required per unit of animal product, the more water is necessary (to produce the feed). The unfavourable feed conversion efficiency for beef cattle is largely responsible for the relatively large water footprint of beef. Sheep and goats have an unfavourable feed conversion efficiency as well, although better than cattle. A second factor is the feed composition, in particular the ratio of concentrates versus roughages and the percentage of valuable crop components versus crop residues in the concentrate. Chicken and pig have relatively large fractions of cereals and oil meal in their feed, which results in relatively large water footprints of their feed and abolishes the effect of the favourable feed conversion efficiencies. A third factor that influences the water footprint of an animal product is the origin of the feed. The water footprint of a specific animal product varies across countries due to differences in climate and agricultural practice in the regions from where the various feed components are obtained. Since sometimes a relatively large fraction of the feed is imported while at other times feed is mostly obtained locally, not only the size but also the spatial dimension of the water footprint depends on the sourcing of the feed

    A Global Assessment of the Water Footprint of Farm Animal Products

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    The increase in the consumption of animal products is likely to put further pressure on the world’s freshwater resources. This paper provides a comprehensive account of the water footprint of animal products, considering different production systems and feed composition per animal type and country. Nearly one-third of the total water footprint of agriculture in the world is related to the production of animal products. The water footprint of any animal product is larger than the water footprint of crop products with equivalent nutritional value. The average water footprint per calorie for beef is 20 times larger than for cereals and starchy roots. The water footprint per gram of protein for milk, eggs and chicken meat is 1.5 times larger than for pulses. The unfavorable feed conversion efficiency for animal products is largely responsible for the relatively large water footprint of animal products compared to the crop products. Animal products from industrial systems generally consume and pollute more ground- and surface-water resources than animal products from grazing or mixed systems. The rising global meat consumption and the intensification of animal production systems will put further pressure on the global freshwater resources in the coming decades. The study shows that from a freshwater perspective, animal products from grazing systems have a smaller blue and grey water footprint than products from industrial systems, and that it is more water-efficient to obtain calories, protein and fat through crop products than animal products

    National water footprint accounts: The green, blue and grey water footprint of production and consumption. Volume 2: Appendices

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    Contents Appendix I. The water footprint of national production (Mm3/yr) Appendix II. Virtual-water flows related to trade in crop, animal and industrial products, per country (Mm3/yr) Appendix III. International virtual-water flows per product category (Mm3/yr) Appendix IV. National water saving related to trade in agricultural and industrial products per country (Mm3/yr) Appendix V. Global water saving related to trade in agricultural and industrial products, per product (Mm3/yr) Appendix VI. The average water footprint per ton of commodity per country, weighted based on origin (WF* in m3/ton) Appendix VII. The water footprint of national consumption per capita, shown by commodity (m3/yr/cap) Appendix VIII. The water footprint of national consumption per capita, shown by major consumption category and by internal and external component (m3/yr/cap) Appendix IX. The total water footprint of national consumption (Mm3/yr) Appendix X. The water footprint of US consumption of agricultural and industrial products, specified per river basin (m3/yr) Appendix XI. The global water footprint of national consumption: maps for selected countrie
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