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Lähestymistapoja elintarvikkeiden vesijalanjäljen arvioimiseksi : kirjallisuuskatsaus | Methodological approaches to the assessment of water footprint of food products Texto completo
2011 | 2012
Lehtinen, Heli | Usva, Kirsi | Maa- ja elintarviketalouden tutkimuskeskus (MTT) / BEL Biotekniikka- ja elintarviketutkimus / Elintarviketutkimus (BEE)
Makean veden kulutuksesta on tullut tärkeä kestävyyden ulottuvuus mitattaessa kulutuksen ja tuotannon kestävyyttä. Tämä kirjallisuuteen perustuva katsaus käsittelee elintarviketuotteiden makean veden kulutuksen ja sen vaikutusten mittaamista. Monitahoinen vesikriisi koettelee elintarvikesektoria: ilmastonmuutos vähentää alueellisesti veden saatavuutta, toisaalta kastelun lisääminen kasvattaa energiankulutusta ja sitä kautta ilmakehän hiilidioksidipäästöjä. Kriisin merkkejä ovat myös veden niukkuudesta aiheutuva ekosysteemien köyhtyminen sekä kilpailu vesivaroista maatalouden ja muiden toimijoiden sekä ruuantuotannon ja non-food-tuotannon välillä. Kansainvälinen vesitilastoinnin suositus IRWS (International Recommendations for Water Statistics) pyrkii harmonisoimaan vesitilastointia mm. kansantalouden tilinpidon kehittämiseksi. Vesitilastointi tarjoaa globaalisti suhteellisen kattavan tietolähteen vedenkulutuksen arvioimiseen. Kansalliset vesitilastot eivät kuitenkaan yleensä huomioi piiloveden tuontia maan ulkopuolelta eivätkä kasvien haihduttamaa vettä. Hoekstran ja Hungin vuonna 2002 esittelemä vesijalanjälkikonsepti pohjautuu virtuaali- eli piiloveden käsitteeseen, laajentaen ja syventäen sitä makean veden kulutuksen globaaliksi mittariksi. Kansainvälinen verkosto Water Footprint Network (WFN) tukee konseptia, joka erottelee sinisen eli ns. teknisen ihmisen käyttöönsä ottaman veden, vihreän eli kasvien käyttöönsä ottaman maaperän veden sekä harmaan veden, jolla tarkoitetaan sen laimennusveden määrää, jolla pilaantunut vesi saataisiin laimennettua referenssitasolle. Elintarvikkeiden vesijalanjäljestä merkittävin osa on yleensä peräisin elinkaaren alkuvaiheesta, kasvintuotannosta. Vesijalanjälkikonseptin on todettu soveltuvan hyvin yrityksen riskien tunnistamiseen ja strategiseen suunnitteluun. Konseptin vahvuutena on pidetty sinisen ja vihreän veden erottelua erityisesti maatalouteen perustuvilla tuotannonaloilla. World Business Council on Sustainable Development (WBCSD) ja UNEP/SETAC Life Cycle Initiative ovat olleet aloitteellisia menetelmäkehityksessä vedenkulutuksen arvioimiseksi osana elinkaariarviointia. ISO on puolestaan aloittanut työn standardin tuottamiseksi vesijalanjäljen laskennasta. Elinkaariarvioinnissa vedenkulutus suhteutetaan useimmiten alueelliseen niukkuuteen. UNEP/SETAC Life Cycle Initiative esittää vaikutusarvioinnin viitekehyksessään mm. että veden kulumista resurssina voidaan käyttää indikaattorina (ns. keskipiste), kun taas vaikutukset ihmisen terveyteen ja ekosysteemiin ovat lopullisia tarkasteltavia haittoja (loppupisteitä). Näihin haittoihin päästään kiinni ns. vaikutusketjumalleilla, joilla hahmotetaan veden kulutuksen syy-seuraus-suhteet. Elinkaariarviointia pidetään tieteellisesti kehittyneenä menetelmänä, joka soveltuu hyvin vertaamaan makean veden käyttöä vaikutuksineen koko tuotteen elinkaaren ja toisaalta laajojen alueiden välillä. Hankaluutena pidetään sitä, että mitkään LCA-menetelmät eivät ole vielä laajasti hyväksyttyjä ja toisaalta arviointitulosten viestimistä pidetään vaativana teknisen monimutkaisuuden vuoksi. Vedenkulutusta on tarkasteltu myös osana talouden materiaalivirtoja ja panos-tuotos-malleja, kuten Mäenpää kehittämässään Suomen kansantalouden mallissa. Suomalaisen elintarviketuotannon näkökulmasta haasteita elintarvikkeen vesijalanjäljen arvioimiseksi riittää sekä datan hankinnan että menetelmäkehityksen puolella. Globaali vesikriisi kuitenkin haastaa yritykset luomaan omat vesistrategiansa sekä vastuullisen hankinnan periaatteensa, joissa veden kulutus ja sen vaikutukset ovat mukana. | Fresh water consumption has become an important dimension of sustainability assessing sustainability of consumption and production. This literature based review deals with measuring the consumption of fresh water and its impacts in production. Water crisis is a complex phenomenom, which strains the food sector: climate change decreases the availability of water regionally, on the other hand irrigation increases energy consumption and CO2 -emissions in the atmosphere. Also ecosystem degradation due to water scarcity and completion over water resources between agriculture and other sector and between food production and non-food production are signs of the crisis. International Recommendations for Water Statistics (IRWS) is aiming to harmonize water statistics for National Accounts among the other things. Water statistics provide globally relatively comprehensive data source for assessing water consumption. However the national water statistics do not normally take the import of virtual water or water evapotranspiration from crop production into account. Water footprint concept presented by Hoekstra and Hung in 2002 is based on virtual (embedded) water extended to a global index of fresh water consumption. International Water Footprint Network (WFN) supports the concept. In the concept the three different types of water use are distinguished: blue water is water technically put into operation by humans, green water is soil water used by plants and grey water is the theoretical amount of dilution water needed to dilute the low-quality water to the reference level. The significant proportion of water footprint of food stuffs is normally derived from the beginning of lice cycle, agriculture. The concept of water footprint is found to be suitable for identifying the risks and strategic planning in companies. The strength of the concept especially in agriculture is the separation of blue and green water. World Business Council on Sustainable Development (WBCSD) and UNEP/SETAC Life Cycle Initiative have taken the initiative in methodology development to assess the water consumption as a part of life cycle assessment. ISO has launched a work to produce a standard of water footprint assessment. In life cycle assessment the consumption of water is normally put in proportion with regional scarcity. UNEP/SETAC Life Cycle Initiative propose in their framework of impact assessment of LCA that water consumption (water as a resource) could be used as an indicator (so called middle point), and impacts on human health and ecosystem are final areas of protection (endpoints).These areas of protection are approached by so called impact-pathways, which are used to conceive the cause and effect relations of water consumption. Life cycle assessment is kept as scientifically advanced method, which is suitable for comparing fresh water use and its impacts in a product level and between wide areas. A difficulty is that none of the LCA methods are widely accepted and on the other hand communicating the results is challenging due their technical complexity. Water consumption is studied also as a part of material flows of national economy and input-output-models as Mäenpää in Finnish national economy model. In the perspective of Finnish food production there are lots of challenges in assessing water footprint of food stuffs. Both data acquisition and methodology development are difficult tasks. However the global water crisis is challenging companies to develop their own water strategies and include the water consumption and its impacts into their principles of responsible purchasing. | v | ok
Mostrar más [+] Menos [-]The nature and impact of climate change in the Challenge Program on Water and Food (CPWF) basins Texto completo
2011
M. Mulligan | M. Fisher | Bharat Sharma | Z. X. Xu | C. Ringler | G. Mah | A. Jarvis | J. Ramrez | J.-C. Clanet | A. Ogilvie | Mobin-ud-Din Ahmad
In this article the authors assess the potential impacts of projected climate change on water, livelihoods and food security in the Basin Focal Projet basins. The authors consider expected change within the context of recently observed climate variability in the basins to better understand the potential impact of expected change and the options available for adaptation. They use multi-global circulation model climate projections for the AR4 SRES A2a scenario, downscaled and extracted for each basin. They find significant differences in the impacts (both positive and negative impacts) of climate change, between and within basins, but also find large-scale uncertainty between climate models in the impact that is projected.
Mostrar más [+] Menos [-]How researchers think they will make an impact: Evidence from the challenge program on water and food
2011
Álvarez, S. | Douthwaite, Boru
The nature and impact of climate change in the Challenge Program on Water and Food (CPWF) basins Texto completo
2011
Mulligan, M. | Fisher, M. | Sharma, B. | Xu ZX | Ringler, Claudia | Mahe G | Jarvis, Andy | Ramírez Villegas, Julián Armando | Clanet, J.C. | Ogilvie, A. | Ahmad, M.
In this article the authors assess the potential impacts of projected climate change on water, livelihoods and food security in the Basin Focal Projet basins. The authors consider expected change within the context of recently observed climate variability in the basins to better understand the potential impact of expected change and the options available for adaptation. They use multi-global circulation model climate projections for the AR4 SRES A2a scenario, downscaled and extracted for each basin. They find significant differences in the impacts (both positive and negative impacts) of climate change, between and within basins, but also find large-scale uncertainty between climate models in the impact that is projected.
Mostrar más [+] Menos [-]The nature and impact of climate change in the challenge program on water and food (CPWF) basins Texto completo
2011 | 2012
Mulligan, Mark; Fisher, Myles; Sharma, Bharat; Xu, Z. X.; Ringler, Claudia; Maheacute, Gil; Jarvis, Andy; Ramiacuterez, Julian; Clanet, Jean-Charles; Ogilvie, Andrew; Ahmad, Mobin-ud-Din | http://orcid.org/0000-0002-8266-0488 Ringler, Claudia
PR | ISI; IFPRI3 | EPTD
Mostrar más [+] Menos [-]Defining benefit sharing mechanisms in the context of water and food related services in the Andean Region
2011
Rubiano, J. | Carvajal, B. | León, J. | Lavado, A. | Carvajal, J. | Perdomo, D.
The nature and impact of climate change in the Challenge Program on Water and Food (CPWF) basins Texto completo
2011
Mulligan, Mark | Fisher, Myles | Sharma, Bharat | Xu, Z.X. | Ringler, Claudia | Mahé, Gil | Jarvis, Andy | Ramírez, Julian | Clanet, Jean-Charles | Ogilvie, Andrew | Ahmad, Mobin-ud-Din
In this article the authors assess the potential impacts of projected climate change on water, livelihoods and food security in the Basin Focal Projet basins. The authors consider expected change within the context of recently observed climate variability in the basins to better understand the potential impact of expected change and the options available for adaptation. They use multi-global circulation model climate projections for the AR4 SRES A2a scenario, downscaled and extracted for each basin. They find significant differences in the impacts (both positive and negative impacts) of climate change, between and within basins, but also find large-scale uncertainty between climate models in the impact that is projected.
Mostrar más [+] Menos [-]Structural Relaxation During Drying and Rehydration of Food Materials--the Water Effect and the Origin of Hysteresis Texto completo
2011
Champion, Dominique | Loupiac, Camille | Simatos, Denise | Lillford, Peter | Cayot, Philippe
The state of water in foodstuffs is a guiding principle in food design, and the equilibrium concept of water activity (Aw) is ubiquitous. It is regarded as a primary variable or “hurdle” in preservation technology, and a key variable influencing chemical reaction during storage. However, the amount of water in any system differs as function of water activity depending whether it is determined by water sorption or desorption. Even though this hysteresis behaviour has already been described in the literature, no physical interpretation of its origin has yet been proposed with respect to detailed molecular organisation. This work shows, for two different food powders, gluten and a milk-based product that the hysteresis disappears when either go through their glass transition. A more complete DSC analysis for gluten during different sorption/desorption cycles demonstrates that the hysteresis is dependent on the ageing of the material, which evolves in the glassy state and is induced by structural relaxation.
Mostrar más [+] Menos [-]The state of the world's land and water resources for food and agriculture: managing systems at risk Texto completo
2011
Assessment of quantitative food web metrics for investigating the influence of land use on warm water fish diets Texto completo
2011
Crane, Derek P | Johengen, Thomas H | Allan, J David
Lotic systems in many regions of the country have experienced habitat degradation and biodiversity loss due to agricultural activity and urbanization. Southeastern Michigan is no exception, as agriculture in the River Raisin watershed and increased urbanization in the Huron River watershed threatens both systems. To further understand the ecological impact of land use on trophic interactions in Midwestern streams and assess the use of a selected set of weighted, quantitative food web metrics as a tool for investigating the influence of anthropogenic disturbance on these systems we compared summer food webs for nine second-order streams. All streams were categorized as developed, undeveloped, or agricultural based on land cover data. Developed and undeveloped streams were located in the Huron River watershed and agricultural streams were located in the River Raisin watershed. Reach-level habitat quality was also assessed at each study site using the EPA's Rapid Habitat Assessment. Fish diets (n = 410) were analyzed to create summer food webs for each site. Comparisons of food webs were made using a suite of weighted, quantitative metrics to identify differences in fish-macroinvertebrate interactions across streams with differing land cover at the sub-basin scale and habitat quality at the local scale. Although undeveloped streams had higher species richness and less habitat degradation, no significant patterns were observed in the quantitative metrics across the three stream categories or based on reach-level habitat conditions. Decapoda, terrestrial Hymenoptera, and Chironomidae were the primary prey taxa in all stream categories. Decapods accounted for the majority of biomass consumed and the pattern of this consumption strongly influenced metric scores. The suite of quantitative metrics tested in this study did not detect significant differences in fish-macroinvertebrate food webs across land use categories, likely in part due to the dominance of a large, tolerant prey taxa in fish diets, regardless of land use and local habitat quality.
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