Overall objective of Baltic Compass’ scenario work is to evaluate the different possibilities that affect the nutrient load to the Baltic Sea generated by agricultural production. Reduction levels are set by environmental goals, taking into consideration the existing and future agricultural practices and restrictions set by socio-economic factors. The evaluations also consider the demands and prerequisites for agricultural production in the future.
VIHMA model is used in Aurajoki river basin in southwest Finland
The evaluations use scientifically tested methodologies to create assessments of the future. The current situation of nutrient leaching (around year 2005) in the selected areas was assessed with tested nutrient leaching models. In the Aurajoki river basin in southwest Finland the VIHMA and Coup models are applied and in the Svärtaå catchment in Sweden, south of Stockholm, the NLeCCS and Fyris models. The Odense river basin in Denmark (Fyn) uses the Daisy and N-LES4 models and in the Polish Narew river basin the SWAT model is applied.
These models were then used to project what might happen to the nutrient leaching from these catchments if there are changes in climate, land use and agricultural practice in the future. This extrapolation was made by testing the models to a real observed situation and then introducing changes in the drivers (such as climate, practices etc.) to see what could happen in the future.
Preliminary results suggest that for Svärtaå, a considerable increase in nutrient leaching is expected due to changed climate and land use, if assuming continuing the same practice as today. These results were presented to the stakeholder group of Svärtaå. This group was selected to represent different stakeholder interests/responsibilities in this area (the Swedish Board of Agriculture, the Swedish Water Authority and the Administrative Board in the County of Södermanland). For the other catchments the stakeholder groups were chosen to represent other interests as well.
The stakeholders suggested measures to be taken to reach the reduction targets. They chose among a long list of alternative measures suggested by Baltic Compass’ work package focusing on best practises. Of these 25 measures about seven were selected for Svärtaå, and similar numbers were also selected in the other catchments. The selection by the stakeholders was based on the measures they regarded applicable to the local conditions, experimental results on their effects, and on measures which were regarded possible to mimic in the models.
After the application of the first proposed measures the results were presented to the stakeholders, who then proposed alternative or modified measures. In this way the scenario work ended up in a package of final measures, well defined in quantitative terms and simulated nutrient leaching.
Scenario work evaluates the nutrient load to the Baltic Sea generated by agricultural production
Preliminary results indicate considerable problems in achieving reduced nutrient leaching close to the ones the stakeholders wanted to achieve. The problems seem even larger for 2050 than for 2020. In 2050 more innovative measures and measures which are costly today but more affordable in the future, are likely to be available. The scenarios could hopefully give us quantitative values of to what degree measures need to be taken to reach the environmental goals and alternatively how far from the goal the reduction will be, based on reasonable assumptions about the future.
Evaluation methodologies used in Baltic Compass’ governance work package are expected to be useful here. The quantitative results of the scenario work are expected to be ready by September and to be presented in October at the “A Greener Agriculture for a Bluer Baltic Sea” conference.