Reactive nitrogen pollution remains a challenge in north west Europe both of excess emission to air and to water. Air pollution of reactive nitrogen from ammonia, nitrogen oxides and nitrous oxide cause secondary particulate matter formation, eutrophication and climate change. Nitrates in water lead to eutrophication. 

Despite plenty of policy initiatives in different region  following on the implementation of the EU Nitrates Directive, the water quality is not improving anymore the last decade. This can to a large extent explained by the fact that the increased occurance of extreme weather events aggrevates nitrogen losses from agriculture and also increase the environemtal burden because stressed ecosystems have more difficulty to absorbe the changes. 

The objective is to perfrom bio-economic modelling to simulate the potential of different policy instruments to reduce the environmental impact with minimal economic impact.