Modelling cost-effectiveness of interrelated emission reduction strategies

Keywords:Environmental pollution; Acidification; Global warming; Agriculture; Abatement cost; Environmental policy interrelations; Ammonia; Nitrous Oxide; MethaneAgriculture is an important source of ammonia, contributing to acidification and eutrophication, as well as emissions of the greenhouse gases nitrous oxide and methane. Technical measures to control emissions of one of these pollutants may have an impact on emissions of others. These side effects, which may be positive or negative, are usually ignored in policy-making.This study investigates interrelations in emission reduction strategies for ammonia, nitrous oxide and methane from agricultural activities in Europe and analyses their impact on cost-effective emission reduction strategies. It presents a modelling framework to identify cost-effective strategies for simultaneous reductions in emissions of various pollutants, considering interrelations. The model includes emissions from various sources and atmospheric transport from the location of emissions to the location where the environmental effect occurs. Emissions can be reduced by several abatement options. The effects of these options, including side effects on emissions of various pollutants, are explicitly incorporated in the model.The model was used for an empirical analysis of interrelations in reducing ammonia, nitrous oxide and methane emissions from the European agricultural sector. In many countries, cost-effective ammonia abatement was found to result in an increase in nitrous oxide emissions. This was caused by measures that effectively reduce ammonia emissions but have adverse side effects on nitrous oxide, such as low ammonia application of manure and animal housing systems with low ammonia emissions. The results also indicated that several measures to reduce nitrous oxide and methane emissions, such as a lower nitrogen content in the fodder, improved fertiliser efficiency and feed additives improving animal productivity in milk and growth, simultaneously reduce ammonia emissions.Furthermore, the model was used to identify cost-effective emission reduction strategies to achieve geographically specific targets for nitrogen and sulphur deposition, contributing to acidification and eutrophication, combined with reduction targets for nitrous oxide and methane emissions from the European agricultural sector, considering the interrelations in reducing emissions from the agricultural sector. The results indicated that cost savings can be obtained when interrelations are considered, because measures with harmful side effects are substituted with measures with beneficial side effects.