RESUMEN
Food production processes may have both positive and negative environmental sustainability impacts. This makes decision-making challenging in the transition towards more sustainable food production systems. In this paper, a new method for presenting environmental impacts in the context of planetary boundaries is demonstrated. This will help food and agricultural producers compare the magnitudes of various environmental impacts. The environmental sustainability impacts of an organic sheep farm in the boreal climate zone in Finland are studied herein first using a life cycle assessment method. The results are then normalized and presented in a planetary boundary framework to ascertain the extent of different environmental impacts. The results show that in the planetary boundary context, there are positive impacts of sheep grazing on biosphere integrity (genetic diversity) and biogeochemical flows and negative impacts on climate change, land use or freshwater use. Magnitudes of the impacts greatly dependent on the assumptions made especially regarding biosphere integrity impacts. In the future, it is crucial that decision-making be based on the evaluation of various environmental impacts and that the focus be more on complex sustainability thinking, rather than on one single environmental impact. This research demonstrates that results from a life cycle assessment can be modified and presented in a planetary boundaries context. A planetary boundary framework approach similar to that proposed herein could be further used to identify different environmental sustainability perspectives and to help one better recognize the multifunctional aspects of the ecosystem processes.
Asunto(s)
Conservación de los Recursos Naturales/métodos , Granjas , Agricultura , Animales , Cambio Climático , Ecosistema , Finlandia , Agua Dulce , Modelos Teóricos , Agricultura Orgánica , OvinosRESUMEN
This study focuses on commercial waste, which has received less attention than household waste in regards to greenhouse gas emission research. First, the global warming potential (GWP) of commercial waste management was calculated. Second, the impacts of different waste fractions and the processes of waste management were recognised. Third, the key areas on which to focus when aiming to reduce the greenhouse gas emissions of commercial waste management were determined. This study was conducted on the waste generated by a real hypermarket in South-East Finland and included eight different waste fractions. The waste treatment plants were selected based on the actual situation. Three different scenarios were employed to evaluate the environmental impact of managing mixed waste: landfilling, combustion and more accurate source separation. The GaBi software and impact assessment methodology CML 2001 were used to perform a life cycle assessment of the environmental impacts associated with the waste management. The results indicated that the total GWP of commercial waste management could be reduced by 93% by directing the mixed waste to combustion instead of landfill. A further 5% GWP reduction could be achieved by more accurate source separation of the mixed waste. Utilisation of energy waste had the most significant influence (41-52%) on the total GWP (-880 to -860â¯kgCO2-eq./t), followed by landfilling of mixed waste (influence 15-23% on the total GWP, 430â¯kgCO2-eq./t), recycling polyethylene (PE) plastic (influence 18-21% on the total GWP, -1800â¯kgCO2-eq./t) and recycling cardboard (influence 11-13% on the total GWP, 51â¯kgCO2-eq./t). A key focus should be placed on treatment processes and substitutions, especially in terms of substitutions of energy waste and PE plastic. This study also clarified the importance of sorting PE plastic, even though the share of this waste fraction was not substantial. The results of this paper were compared to those of previous studies. The output of this analysis indicated that the total GWP can be significantly reduced by identifying an alternative recycling or incineration location for cardboard where it is used to substitute virgin material or replace fossil fuels respectively. In conclusion, it is essential to note that waste management companies have a notable influence on the emissions of commercial waste management because they choose the places at which the waste fractions are treated and utilised.
Asunto(s)
Gases de Efecto Invernadero , Instalaciones de Eliminación de Residuos , Administración de Residuos , Finlandia , Efecto Invernadero , Eliminación de ResiduosRESUMEN
The ongoing trend in the public sector is to make more sustainable procurements by taking into account the impacts throughout the entire life cycle of the procurement. Despite the trend, the only deciding factor can still be the total costs. This article answers the question of how greenhouse gas (GHG) emissions should be taken into account in municipal solid waste (MSW) management when selecting an incineration plant for source separated mixed MSW. The aim is to guide the decision making of MSW management towards more environmentally friendly procurements. The study was carried out by calculating the global warming potentials (GWPs) and costs of mixed MSW management by using the waste composition from a case area in Finland. Scenarios of landfilling and combustion in three actual waste incineration plants were used to recognise the main processes that affect the results. GWP results show that the combustion of mixed MSW is a better alternative than landfilling the waste. The GHG results from combustion are greatly affected by emissions from the combustion and substituted energy production. The significance of collection and transportation is higher from the costs' perspective than from the point of view of GHG emissions. The main costs, in addition to collection and transportation costs, result from the energy utilization or landfilling of mixed MSW. When tenders are invited for the incineration location of mixed MSW, the main focus should be: What are the annual electricity and heat recovery efficiencies and which are the substituted fuels in the area? In addition, in the case of a fluidized bed combustor it is crucial to know the combusted share of mixed MSW after preparing solid recovered fuel (SRF) and the treatment of rejects. The environmental criteria for the waste incineration plant procurements should be made in order to obtain clear instructions for the procurement units. The results can also be utilized more widely. The substituted fuels in the area and the effect of the plant location on the utilization of the produced energy can already be identified when planning an appropriate site for the waste incineration plant.