RESUMO
The possibility of using bioenergy as a climate change mitigation measure has sparked a discussion of whether and how bioenergy production contributes to sustainable development. We undertook a systematic review of the scientific literature to illuminate this relationship and found a limited scientific basis for policymaking. Our results indicate that knowledge on the sustainable development impacts of bioenergy production is concentrated in a few well-studied countries, focuses on environmental and economic impacts, and mostly relates to dedicated agricultural biomass plantations. The scope and methodological approaches in studies differ widely and only a small share of the studies sufficiently reports on context and/or baseline conditions, which makes it difficult to get a general understanding of the attribution of impacts. Nevertheless, we identified regional patterns of positive or negative impacts for all categories - environmental, economic, institutional, social and technological. In general, economic and technological impacts were more frequently reported as positive, while social and environmental impacts were more frequently reported as negative (with the exception of impacts on direct substitution of GHG emission from fossil fuel). More focused and transparent research is needed to validate these patterns and develop a strong science underpinning for establishing policies and governance agreements that prevent/mitigate negative and promote positive impacts from bioenergy production.
RESUMO
Chemical pesticides are widely used in modern agriculture but their potential negative impacts are seldom considered in environmental assessments of food products. This study aims to assess and compare the potential freshwater ecotoxicity impacts due to pesticide use in the primary production of six food products: chicken fillet, minced pork, minced beef, milk, pea soup, and wheat bread. The assessment is based on a detailed and site-specific inventory of pesticide use in the primary production of the food products, all of which are produced in Sweden. Soybeans, used to produce the animal-based food products, are grown in Brazil. Pesticide emissions to air and surface water were calculated using PestLCI v. 2.0.5. Ecotoxicity impacts were assessed using USEtox v. 2.01, and expressed in relation to five functional units. The results show that the animal-based food products have considerably larger impact potentials than the plant-based food products. In relation to kg pea soup, impact potentials of bread, milk, minced beef, chicken fillet and minced pork are ca. 2, 3, 50, 140 and 170 times larger, respectively. All mass-based functional units yield the same ranking. Notably, chicken fillet and minced pork have larger impacts than minced beef and milk, regardless of functional unit, due to extensive use of pesticides, some with high toxicity, in soybean production. This result stands in sharp contrast to typical carbon footprint and land use results which attribute larger impacts to beef than to chicken and pork. Measures for reducing impacts are discussed. In particular, we show that by substituting soybeans with locally sourced feed crops, the impact potentials of minced pork and chicken fillet are reduced by ca. 70 and 90%, respectively. Brazilian soybean production is heavily reliant on pesticides. We propose that weak legislation, in combination with tropical climate and agronomic practices, explains this situation.
Assuntos
Contaminação de Alimentos , Carne/análise , Praguicidas/efeitos adversos , Verduras/química , Ração Animal , Animais , Brasil , Ecotoxicologia , Água Doce , SuéciaRESUMO
The inclusion of ecotoxicity impacts of pesticides in environmental assessments of biobased products has long been hampered by methodological challenges. We expanded the pesticide database and the regional coverage of the pesticide emission model PestLCI v.2.0, combined it with the impact assessment model USEtox, and assessed potential freshwater ecotoxicity impacts (PFEIs) of pesticide use in selected biofuel feedstock production cases, namely: maize (Iowa, US, two cases), rapeseed (Schleswig-Holstein, Germany), Salix (South Central Sweden), soybean (Mato Grosso, Brazil, two cases), sugar cane (São Paulo, Brazil), and wheat (Schleswig-Holstein, Germany). We found that PFEIs caused by pesticide use in feedstock production varied greatly, up to 3 orders of magnitude. Salix has the lowest PFEI per unit of energy output and per unit of cultivated area. Impacts per biofuel unit were 30, 750, and 1000 times greater, respectively, for the sugar cane, wheat and rapeseed cases than for Salix. For maize genetically engineered (GE) to resist glyphosate herbicides and to produce its own insecticidal toxin, maize GE to resist glyphosate, soybeans GE to resist glyphosate and conventional soybeans, the impacts were 110, 270, 305, and 310 times greater than for Salix, respectively. The significance of field and site-specific conditions are discussed, as well as options for reducing negative impacts in biofuel feedstock production.