Costs and benefits of ammonia and particulate matter emission abatement and interactions with greenhouse gas emissions in German agriculture

摘要

In the past decades, agricultural and particularly livestock production have increased with population growth and increasing demand for food, especially for livestock products, at global level. This trend is expected to continue in the coming decades and may even be fortified by an increasing demand for non-food biomass in an economy based on renewable biological resources. Agriculture influences also the state of the environment. Agriculture has been associated with expansion into natural ecosystems, adversely affecting biodiversity and has a large share in the global emissions of greenhouse gases and ammonia (NH3) and in the release and formation of primary and secondary fine particulate matter (PM2.5). NH3 emissions can lead to a loss of biodiversity in nitrogen-limited terrestrial ecosystems and can form secondary PM2.5 in the atmosphere. PM2.5 emissions may affect human health by causing respiratory and cardiovascular diseases and a reduction in life expectancy. As NH3 and PM emissions partly originate from the same production activities as greenhouse gases, interactions between NH3 and PM emission abatement and greenhouse gas emissions may exist. Emissions can be reduced by technical measures or by shifts towards a diet low in animal-based food products, because plant-based food products cause fewer emissions than animal-based food products. In Germany, agriculture contributes about 95% of the total NH3 emissions and 5% to primary PM2.5 and 8% to greenhouse gas emissions. Because of the environmental impacts and subsequent governmental regulations, there is a need to reduce emissions of NH3, PM2.5 and of greenhouse gas emissions significantly. The main objective of this thesis research was to increase the understanding of the full effects of NH3 and PM emission abatement in agriculture. Particularly, it aimed to quantify and compare farmers’ costs and society’s benefits of reducing NH3 and PM emissions in agriculture in Germany while considering interactions with greenhouse gas emissions and to identify cost-efficient NH3 and PM emission abatement measures. Both technical NH3 and PM emission abatement measures and a diet shift were examined with respect to the abatement costs and the benefits in terms of avoided damage costs of impacts on human health, terrestrial biodiversity and the climate. The analysis combined agricultural emission modelling and integrated environmental impact assessment, applying the impact-pathway approach, complemented by literature analysis.The abatement potentials ranged from 2 to 45% for NH3 emissions, from 0 to 38% for PM2.5 emissions and from 0to 49% for greenhouse gas emissions. The abatement potentials of a diet shift exceeded those of technical abatement measures. All air pollutant abatement measures affected greenhouse gases, in most cases synergistically. The average abatement costs ranged from 2.7 to 25.6 EUR per kilogramme NH3 reduced, from 7.5 to 31.2 EUR per kilogramme PM2.5 reduced and 0.01 to 0.03 EUR per kilogramme greenhouse gas emissions reduced. The average benefits were 24.5 EUR per kilogramme NH3 reduced and 68.3 EUR per kilogramme PM2.5 reduced. The benefits of reduced health damage costs were higher than those of reduced biodiversity loss, resulting in higher benefits of PM2.5 reduction. The benefits of the reduction of greenhouse gas emissions were 0.09 EUR per kilogramme. In conclusion, synergies with greenhouse gas mitigation reduced the abatement costs per unit of emission type, increased the benefits and improved the cost-efficiency of air pollutant abatement measures. This finding indicates that air pollutant abatement and greenhouse gas mitigation should be analysed together and that environmental policy design should consider interactions. The abatement potentials of technical measures were limited and should be complemented by changes in food consumption patterns to meet politically agreed emission reduction targets. Besides emission reductions, diets with low consumption of animal-based food provided land for alternative uses such as food production, lignocellulosic biomass production or biodiversity conservation that have the potential to reduce pressure on land from increasing demand for food by a globally growing population or for lignocellulosic biomass in an economy based on renewable biological resources.