Cost-Effective Nutrient Emission Reductions in the Rhine River Basin

Abstract

Nitrogen and phosphorous emissions in the Rhine river basin and measures and quota restrictions to reduce them are distinguished between in an optimisation model which calculates how to reach a desired load to the North Sea in a cost-effective way. Nutrients are emitted by farm types (at most 10 per region) and wastewater and sewage treatment plants in 13 regions and nutrients are retained by wetlands at the basin level. Cost abatement curves are fitted for each agricultural sector using the output of a simulation model which describes the interaction between agriculture, industry and wetlands. The cost effective solution suggests to substantially abate emissions by constructing wetlands. A sensitivity analysis with the model shows that if the climate becomes wetter, possibly due to climate change, the emissions of agricultural sources gain importance and more measures should be taken at the farm level, reducing the total cost by 1.6% as compared to the case without climate change.