Assessing water scarcity impact of food products applying AWARE method within LCA | Elintarvikkeiden vesiniukkuusvaikutusten arviointi elinkaariarvioinnissa AWARE-menetelmällä

An increasing number of people faces chronic water shortage, and 17% of watersheds suffer from overconsumption. Agriculture is the main water consumer globally, and irrigation comprises most of the agricultural water consumption. Irrigation more than doubled between 1960 and 2000. In many cases, water-intensive goods are produced in water-scarce countries, and virtual (irrigation) water is traded by agribusinesses. Food products potentially have an impact on local water resources in the production area. The water scarcity footprint of products can be calculated by applying the AWARE method within the life cycle assessment (LCA). AWARE is a relatively new method but is already recommended by several influential organisations (e.g. the European Commission), and it will probably therefore be applied widely in the coming years. The goal of this thesis was to study how the AWARE method compares to other water scarcity footprint methods in LCA for food products, study the water scarcity footprint of three common food products in Finland and the hotspots of the food products, and identify further LCA research needs for improving the performance of the chain and for harmonised LCA. Three food case studies were selected to assist in answering the research questions: milk (Article I), coffee (Article II), and broiler meat (Article III) produced for the Finnish market. Basic knowledge of the suitability of the AWARE method for a food product was produced in the milk case study. The water scarcity footprint of all three foodstuffs was assessed, and hotspots were identified. The interpretation of the results was supported by a detailed analysis of the challenges especially in the life cycle inventory phase and some further sensitivity analyses. Finally, recommendations for compiling good-quality life cycle inventory (LCI) data in water scarcity assessment to support the achievement of the LCA study’s goal were made. To support the analysis, the new terms ‘internal development LCA’ and ‘external harmonised LCA’ were proposed. An internal development life cycle assessment refers to a life cycle assessment that aims to evaluate the environmental effects of a specific product or service to support the development of the environmental performance of the product. External harmonised LCA is needed when comparisons, benchmarking, or public propositions are executed. In contrast with internal development LCA, the methods or their application cannot be selected freely according to the goal of the study in external harmonised LCA, but specific rules for LCA, Environmental Declaration Criteria, or Product Category Rules are followed. The LCIs in the case studies were analysed, and observations were made especially concerning the following aspects: identifying relevant processes and elementary waterflows; data collection methods; assumptions due to missing data or default origins; raw data modification methods; allocation methods and the link between inventory and impact assessment. A commonly observed challenge was the lack of knowledge of the origins of the inputs. A general conclusion about the AWARE method is that the water scarcity footprint result reflected both water consumption and the characteristics of the region in the form of a characterisation factor. This dissertation work’s results support the claim that the indicator has a clear and understandable physical meaning. Food product chain hotspots were recognised. If irrigation was applied, it dominated the water scarcity results. Irrigation dominated the water scarcity results of primary production, but even without irrigation, the magnitude of primary production was remarkable. The consumption stage may also be important for the water scarcity footprint. Water scarcity footprints have a strong spatial nature. The effect of geographical location on water scarcity footprint is especially important. Because of the regional character of water scarcity footprint, it seems it is generally impossible to define any normal or typical level of water scarcity footprint result of a certain food product, but products from different origins will have different water scarcity footprints. However, with stronger evidence in the scientific literature, it is likely that the typical water scarcity footprints of certain food items produced in certain regions can be defined in the future. According to the results of this thesis, improved primary data production and traceability to determine the origins of the inputs is needed in many cases to improve the results’ accuracy. The spatial nature of the water scarcity footprint considerably increases the need for regionalised (spatially differentiated) data. The production of geographically representative datasets is time- and resource-consuming work, but it is necessary for improving the accuracy of LCA studies applying AWARE. All data should be compatible with the definition of consumptive water in ISO 14046. Using theoretically modelled data instead of primary data may result in inaccuracy. This is an important question, especially with the volume of irrigation water, because the relative share of water for irrigation may be remarkable if included in the production chain. In harmonised LCA, the calculation rules should guarantee the harmonisation, at least at a reasonable level, but product category rules (PCRs) do not necessarily instruct the use of AWARE at a detailed level. Regarding the water scarcity effect, the PCR should list when primary data must be produced about the input, and when information about the origin of the input is mandatory, even if there is no other basic information about the product. In particular, the evaluation of irrigation water must be instructed.

Kasvava osa maailman väestöstä kärsii kroonisesta vesiniukkuudesta ja 17 % vesistöalueista kärsii liiallisesta vedenkulutuksesta. Maailmanlaajuisesti maatalous on merkittävin vedenkuluttaja, ja suurin osa maatalouden vedenkulutuksesta johtuu kasteluveden käytöstä. Vesi-intensiivisiä tuotteita tuotetaan usein vesiniukoissa maissa ja virtuaalista (kastelu)vettä ostetaan ja myydään maataloustuotteiden myötä. Tuotteiden vesiniukkuusvaikutuksia voidaan mitata elinkaariarvioinnissa (LCA) AWARE-vaikutustenarviointimenetelmällä. AWARE on suhteellisen uusi menetelmä, mutta useat vaikutusvaltaiset organisaatiot (esim. Euroopan komissio) suosittelevat sitä jo, ja siksi menetelmää tultaneen todennäköisesti soveltamaan laajalti tulevina vuosina. Tämän väitöskirjatyön tavoitteena oli tutkia, miten AWARE-menetelmä vertautuu muihin vesiniukkuuden arviointimenetelmiin elintarvikkeiden elinkaariarvioinnissa, tutkia kolmen Suomessa yleisen elintarvikkeen eli maidon, kahvin ja broilerinlihan vesiniukkuusvaikutusta ja niiden ongelmakohtia, sekä tunnistaa lisätutkimustarpeita ketjun ympäristösuorituskyvyn parantamiseksi ja harmonisoidun elinkaariarvioinnin tekemiseksi. Kaikkien kolmen elintarvikkeen vesiniukkuusvaikutukset arvioitiin ja vesiniukkuuden kannalta oleelliset tuotantovaiheet tunnistettiin. Tulokset osoittavat, että jos kastelua käytettiin, se hallitsi vesiniukkuusvaikutustuloksia, mutta ilman kasteluakin alkutuotannon merkitys oli huomattava. Myös kulutusvaihe voi olla tärkeä vesiniukkuusvaikutuksen kannalta. Maantieteellisen sijainnin vaikutus veden niukkuuteen on erityisen tärkeä. Vesiniukkuusvaikutusten arviointi on mahdollista elintarvikkeille, mutta vesiniukkuuden alueellisen luonteen vuoksi on erittäin haastavaa määritellä yleisesti tietyn ruoka-aineen normaalia tai tyypillistä vesiniukkuusvaikutuksen tasoa, jos sitä tuotetaan eri puolilla maailmaa. Monissa tapauksissa tarvitaan enemmän primääritiedon tuotantoa ja syötteiden alkuperän jäljitettävyyttä, jotta tulosten tarkkuus paranee. Vesiniukkuusvaikutuksen alueellinen luonne lisää huomattavasti alueellisesti eriytetyn tiedon tarvetta. Maantieteellisesti edustavien aineistojen tuottaminen on aikaa ja resursseja vievää työtä, mutta se on välttämätöntä, jotta ymmärrys ruuan vaikutuksesta veden niukkuuteen lisääntyy.

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